Wood With Strings

Another Moving Experience

2011-10-09T11:41:00.009+08:00

When we were forced to find a new rental property last year, my guitar-building pursuits were seriously disrupted while we hunted for a suitable house, packed innumerable boxes, moved our accumulation of "stuff", then found homes for everything once we'd made the move. During the weeks that followed, my attention was focussed on building a workbench from scratch and establishing some semblance of order in my new workshop. Having achieved all that, I enjoyed more productive times and was pleased to be able to complete a couple of guitars and make good progress with the others I've featured recently on this blog.

Stability hasn't lasted long however, and barely 12 months later we've taken a critical look at our situation from the point of view of finances and lifestyle and have purchased our own home. As a temporary measure, I'll set up shop in the double garage, but the long-term goal will be to build a workshop at the rear of the property with the luxury of being able to give consideration to the heating and cooling, lighting and storage requirements best suited to our budget and the specialised needs of my guitar building hobby. In many respects it's a distraction I'd rather not face, but I'm confident that the planning, expense and hard work involved will pay off in the long term. It's my hope that I'll be much more inclined to spend time building guitars, particularly through our extreme summers when it's too easy to spend what spare time I do have lounging around in the air-conditioned house!

Updates to my blog will slow to a trickle in the weeks ahead, however, normal service will be resumed as soon as possible.

Cheers
Pete

Saddle Slots and Bridge Pin Holes

2011-09-25T18:45:00.008+08:00

Although I'm nowhere near ready to make use of them, I've spent some time lately working on the bridges destined for the two guitars I have under construction for no other reason than it's a job I can devote short periods of time to in a spare moment, or treat as light relief between more demanding or time-consuming tasks.

To facilitate drilling of the bridge pin holes in a perfectly straight line, parallel to the saddle slot I've previously routed out, I glue a small wooden block to the front edge of the bridge blank on the treble end prior to cutting the bridge outline. I trim the block carefully using my disk sander so that as the bridge is slid along a makeshift fence attached to my bench drill's table, the centre of each hole will be equidistant from the slot. Having guaranteed alignment in that direction, I need only take care then to align the bit with the string spacings marked on the bridge as I prepare to drill each hole (a white ball-point pen is a godsend when marking dark woods like this ebony). A brad-point bit makes accurate alignment much easier and produces a perfectly clean hole provided it breaks out through the lower surface of the bridge into a backing board of MDF or scrap timber.

With the bridge pin holes drilled parallel to the line of the saddle, there's a consistent break angle for the strings as they pass over it. While some reason that this guarantees an equal downward string pressure along the saddle's length, the fact that string gauges and tensions vary from string to string casts doubt on the validity of that argument. A slight increase in the saddle's height towards its centre and the potential use of radically altered tunings such as "Orkney" tuning (CGDGCD low to high) complicate the matter still further. Whatever its other merits though, it's a neat look and I'm assured of adequate downward pressure on the saddle and therefore good transference of the strings' energy to the soundboard.

It seems there's no hard and fast rule where bridge weights are concerned; popular wisdom has values falling within a fairly wide range. Given that there are a multitude of factors influencing the guitar's sound, I somehow doubt I'll ever build enough instruments to draw any meaningful conclusions where small variations in bridge weight are concerned; there are so many other variables likely to have a more significant and measurable effect should I feel the urge to experiment. That being the case, I'm happy to aim for a more or less consistent bridge weight from one guitar to the next. With ebony bridges such as these, I shoot for a weight of between 30 and 35 grams, making use of a cheap digital gram scale as I shape and shave the bridge wings to their final thickness.

Useful links:
Routing the Saddle Slot

Cheers

Pete

The Fingerstyle Guitar - Gluing the Soundboard and Back

2011-09-03T13:40:00.007+08:00

There are several commonly used methods of clamping the soundboard and back as they're glued to the rims, but the technique pictured here is the one I've adopted; it works very well, and I feel no need to explore other options. I use thin bungee-cord to apply the necessary clamping force, with a caul made from masonite and cork sheet in place to distribute pressure evenly around the guitar's perimeter. The caul focuses clamping pressure on the edge of the back or soundboard, preventing any deformation of the top or back plates which the tightly stretched cord might otherwise cause. It also serves to protect the delicate soundboard wood from damage where the cord breaks sharply over its edge. I trim the top and back plates to within a few millimetres of their final dimensions prior to clamping; there's minimal overhang and therefore no leverage brought to bear by the bungee-cord on the edge of the plates.

I haven't become anywhere near proficient enough with hot hide glue to consider using it to attach the soundboard and back plate to the rims, and in any case, I'm not convinced of the benefits of doing so. That being the case, I'm happy to continue using Titebond Original, applying it the gluing surface of the linings with a 1 inch foam roller after the rim assembly has been securely clamped in the outside mould. The roller allows me a high degree of control over the quantity of glue applied and, if I've judged it well, there's negligible glue squeeze-out at the intersection of the linings with the top and back plates and therefore little need for clean-up inside the guitar body. I attach the back first, the advantage being that once the bungee-cord has been secured, I can flip the entire assembly over and inspect the interior of the guitar through an opening in the base of the mould, cleaning up what squeeze-out there is with a damp sponge.

Click any of the photos for a larger view.

Cheer

Pete

The Fingerstyle Guitar - Notching the Kerfed Linings

2011-08-27T15:46:00.014+08:00

Once the kerfed linings are glued to the sides, the sandpaper-lined concave dishes I made use of when shaping and gluing the top and back braces serve their other purpose by helping me sand a drop-off onto the edges of the rim assembly to match the curvature of the back and top plates.

I can then use a Dremel rotary tool to rout pockets into the linings to accommodate the brace ends. Using the more traditional kerfed linings whose saw kerfs face into the guitar body, there's always a danger that if one or both edges of a brace pocket happen to be in close proximity to the kerfs, a chunk of wood will be dislodged as the pocket is cut. With reverse-kerfed linings, however, the individual sections of wood between the kerfs are firmly glued to the sides and serious chipping of the exposed face of the lining on either side of the brace pocket is far less likely, provided some simple precautions are taken.

When routing the brace pockets, it's important that the Dremel is guided in such a way that the router bit's clockwise rotation doesn't contribute to tearing or chipping of the linings as the pocket is cut. This is particularly important to observe where the left-hand edge of the brace pocket is concerned (i.e., with the guitar side facing me). With that in mind, I make my first cut towards me in the direction of the guitar side along this left-hand margin, easing the router bit into the lining for the equivalent of around half the bit's diameter; a second shallow entry cut on the right-hand side of the pocket defines its width. Several light passes are made from left to right until a single recess is created between the two entry cuts. I repeat this process until the recess extends to the guitar's side and make final adjustments until the end of the brace fits snugly within the pocket. It's difficult to avoid chipping entirely, but by guiding the router in the manner I've described, it's of a minor nature and can be easily cleaned up with sandpaper.

I rout the pockets in pairs, beginning at the tail-block end of the body. If the first pair of pockets is accurately marked and cut, the centre-line of the back will be correctly aligned from that point on. If a minor adjustment to the back alignment is required, the pockets can be modified accordingly. The second, and subsequent pairs of pockets can then be more accurately positioned, with correct alignment of the back more firmly established as each pair is cut.

Some builders postulate that because reverse-kerfed linings stiffen the rim assembly once attached, there are resultant improvements in the sound of instrument. Occasionally, it seems, views such as this are repeated often enough by individuals held in high regard within the luthier community that they become accepted as fact, whether or not they've been held up to close scrutiny. I acknowledge that I have a lot to learn and always try to have an open mind when reading of the experiences and opinions of other more experienced builders, but after looking at popular wisdom such as this from all angles, I'm left unconvinced. For what it's worth, my personal view is that while it's somewhat helpful having a stiffer rim to work with in the course of constructing the instrument, from the point at which the back and soundboard are attached to the rims, any contribution the linings may have made to the rims' stiffness is eclipsed by the strength of the top and back in compression. I suspect that in the finished instrument, the linings - reversed or otherwise - play little part beyond their primary purpose: to provide a gluing surface for the top and back plates.

Cheers
Pete

The Fingerstyle Guitar - Side Reinforcement

2011-08-26T10:18:00.004+08:00

For almost as long as I've been building guitars I've followed the lead of others and have fitted kerfed linings to the rims, then installed wooden reinforcement strips to span the sides between the top and back linings. Although this remains common practice, it seems an increasing number within the lutherie community are coming to the view that this could potentially do more harm than good, the thinking being that if the guitar sustains a significant impact, the area of relative weakness created at the intersection of the side reinforcement and the lining could contribute to a crack developing at that point - it makes sense to me.

For this guitar then - and for its rosewood and spruce companion - I've chosen an alternative approach which is to to glue cloth bias tape across the full width of the sides at regular intervals and install the linings over the top of it. The rationale for this is that as the glue-impregnated cloth spans the entire side and will remain somewhat flexible, the weak point I've described is largely avoided. In the unlikely event that a crack develops in one of the sides for whatever reason, the tape will provide a measure of protection against the crack propagating along the length of the side - at least until a permanent repair can be carried out.

Useful Links:
Installing Side Tapes

Cheers
Pete

New Wood Purchases

2011-08-22T19:20:00.037+08:00

I have a love/hate relationship with our strong Australian dollar at present. It's too convenient an excuse to click the "Buy Now" button when I spot particularly desirable pieces of wood on favourite web sites such as Allied Lutherie's but, of course, it's also of benefit once I've given in to temptation. Resistance is futile, it would seem.

Ample evidence of my recent weakness can be seen below. Those poor souls similarly afflicted with "Wood Acquisition Syndrome" can click the pictures for a closer look.

European Spruce

Port Orford Cedar

European Spruce needs no introduction, but Port Orford Cedar is a relatively uncommon tonewood. Luthier's Mercantile has this to say about it:

Similar in appearance and scent to Alaskan Yellow Cedar, Port Orford Cedar is stiffer, lighter and thus more suitable for soundboards. Indeed, it is highly sought after for the bold, robust, responsive tone that it imparts on an instrument. It is very even textured, with a slight golden-white color and tight, even grain. A great advantage to the builder is that this wood is more immune to splitting than absolutely any other soundboard wood.

The Port Orford Cedar is in transit as I write this and I'm impatient to inspect it, flex it, tap it - and smell it! Aside from its promised tonal and structural advantages, I'm looking forward to experiencing the pungent peppery smell it's said to impart to a completed instrument. It's almost worth combining it with a back and side set of Claro Walnut for that reason alone given walnut's delicious aroma. Such an instrument would surely be the ultimate "perfumed guitar"!

Useful links:
Port Ordford Cedar - Stansell Guitars

Cheers
Pete

Kerfed Linings

2011-08-02T09:18:00.006+08:00

Kerf: a slit or notch made by a saw

Pre-made kerfed linings are readily available from any number of suppliers, but given their expense and fragility, I prefer to fabricate my own, leaving a little more wood between the termination of each saw cut and the opposite face of the lining than is generally present on those available commercially. Even with that precaution, I like to pre-bend the mahogany strips with the aid of a bending iron to match the contours of the guitar side. Breakages are rare, but if I should happen to snap one, it makes sense to discard it, or at least reserve it for areas where the break won't be visible. Given the attention to detail lavished on the other aspects of a hand-built instrument, I find it incomprehensible when I see pictures of the interior of a guitar in which joins in the linings are in plain view through the soundhole. I'm a little uncomfortable too with saw cuts whose spacing or depth varies noticeably along the length of the strip. Using my band-saw and the crude but effective fixture pictured below, I'm able to produce evenly spaced cuts of a consistent depth.

After several less than satisfactory attempts using a router to apply a rounded profile to what will be the inner corner of the strips, I discovered that by planing a series of facets onto the appropriate edge with a small block plane, I could quickly and easily blend them into a smooth curvature with a sanding block. It reinforces the fact that sometimes, the simple, non-mechanised approach is best!

Cheers

Pete

A Claro Walnut/Sitka Spruce 000 - Free to Good Home!

2011-07-31T18:07:00.027+08:00

I've made great advances with the last two guitars I've completed in terms of build quality and tone and I'm afraid I'm a little lacking in motivation when it comes to completing this one. I guess that's a little strange given my usual passion for guitar building, but considering that I began its construction quite some time ago and would much rather be working on my new instruments, putting into practice important lessons recently learned, I'm inclined to forgive myself for this half-hearted attitude.

The photograph above doesn't do the claro walnut back and sides justice; in its present raw state, the wood looks pretty uninspiring. Under finish, however, its stunning figure will be fully revealed and will be the icing on what I hope will be a very successful cake!

Tapping on this unusually marked Sitka spruce soundboard in its unfinished state gives me reason to be confident. The body is very resonant, the standard of workmanship is acceptable and construction is far enough advanced that I'm sure I can muster the enthusiasm to finish it. This guitar's state of completion will fall into line with my two latest instruments when they are ready to receive bindings. From that point on I'll attempt to complete the remaining steps on all three guitars concurrently.

Click for a closer look.

For what will hopefully be the last time, I plan on finding an appreciative recipient and making a gift of one of my instruments. It's certainly been very satisfying to have delivered my last two guitars to keen players free of charge, but once this guitar finds a new home, foregoing that pleasure and at last deriving some meagre income from my hobby is a prospect that's becoming increasingly attractive. Semi-retirement (and a new band-saw) beckons!

Cheers

Pete

The Fingerstyle Guitar - Head Block, Tail Block and Linings

2011-07-10T20:04:00.004+08:00

Having braced the top, it's time to temporarily suspend my excitement and spend some time on the rims. For me, this is perhaps the least inspiring stage of construction and the reason I find it preferable to have a ready-made stock of head blocks, tail blocks and kerfed lining strips which I've prepared in batches over the preceding months. With a supply of blocks and linings on hand, I can make short work of fitting them to the guitar's sides and move on quickly to more interesting tasks.

I laminate my tail blocks using three layers of wood, the middle layer of which has its grain oriented at right angles to the two outer layers, parallel with the grain of the sides. For the little additional effort involved, I can feel confident that the block will remain intact and a side crack will be avoided should the guitar ever be dropped on its end pin.

In the belief that setting modest targets fuels motivation and sustains momentum, I'm setting myself the goal of attaching the head and tail blocks and installing the kerfed linings in the week ahead.

Cheers
Pete

The Fingerstyle Guitar - Soundboard Voicing

2011-06-30T22:40:00.032+08:00

Like many novice guitar builders I was inclined to overbuild my early guitars, the mortal fear of them imploding tending to override any suspicion that I was robbing them of their full tonal potential. It's been difficult to leave that mindset behind me, but with a conscious effort to "lighten up", and with the wisdom of more experienced luthiers in mind, I'm venturing further from my previous comfort zone with each guitar in an effort to increase their responsiveness. To that end, I've significantly reduced the mass of my soundboard braces, ever mindful of the delicate balance necessary between lightness and strength. Ironically, it's because of advice from those same sources that I'm inclined to leave the soundboard itself a little thicker than I may once have done.

John Mayes' "Advanced Voicing" DVD provided me with a way forward where carving the soundboard braces is concerned. Without a doubt, watching John shave and shape the soundboard braces then tap on the top to assess the changes he'd brought about has given me a much better insight into the process than I'd been able to gain through simply reading about other luthiers' methods in that regard. As John clearly demonstrates, judicious removal of small amounts of mass from one or more braces can make a big difference to the responsiveness of the soundboard. It's still a somewhat mysterious and inexact science for me, but recent results suggest that I'm heading in the right direction at last.

There's some carving of brace ends and final finish sanding remaining, but essentially, the redwood top is as resonant as I can confidently make it without sacrificing necessary strength. Its pitch when tapped is significantly different to that of the Sitka spruce top I've recently brought to this level of completion and it will be interesting to compare the two guitars when they're strung up. For my own future reference, I intend to document each top's overall weight and brace dimensions as well as record their tap tones with a hand-held Zoom recorder, the thinking being that over time, as I complete more instruments, I'll be able to correlate these measurements with their sound when played.

Cheers
Pete

Postscript: Since publishing this post yesterday, I've capped the "X" brace intersection with a small piece of spruce and the relative pitches of the two tops when tapped are now much closer. It explains the startling difference I noticed yesterday and is a great demonstration of how this small addition can significantly increase the overall stiffness of the top.

The Fingerstyle Guitar - Fun With Hide Glue

2011-06-26T17:40:00.016+08:00

This has been my first attempt at using hot hide glue, and although there were some tense moments - including one abortive attempt at attaching the bridge plate - major disasters were averted.

Because hide glue begins to gel quite rapidly once it cools, it's important to apply it and have the piece being glued clamped in position before that happens. Before I glued each brace, I found it useful to have several practice runs without glue to establish the sequence of steps I'd follow and to make sure I knew in advance where and in what order I would position the "go-bar" clamps. Despite the benefit of those dry-runs, I wasn't able to remain cool, calm and collected at all times and I still managed to make a gooey mess on a couple of occasions. Thankfully, of all the glues I've used, hide glue is by far the easiest to clean up. As I found out on my first attempt at gluing the bridge plate, the worst that can happen is that the soundboard, brace or bridge plate need to be cleaned of glue with a little warm water, ready for a second attempt when things have dried out. The advice I've read repeatedly - and with some relief - is that using hot hide glue gets easier with practice!

Cheers
Pete

More Fun With Rosettes

2011-06-22T22:24:00.007+08:00

After the recent experience of having several instruments under construction at once, I vowed I'd restrict myself to building one instrument at a time once they were completed. That promise was soon broken however, as evidenced by this East Indian rosewood/Sitka spruce guitar which I'm building alongside my claro walnut/redwood fingerstyle instrument.

Where the rosette is concerned, I decided to contrast the spruce top with a dark wood - again using a radial design. Macassar ebony seemed a natural choice, with a dash of red adding some zing to the combination. Top, back and side purflings will extend this black/red theme.

Cheers
Pete

The Fingerstyle Guitar - Installing the Rosette

2011-06-19T13:59:00.019+08:00

I'd probably still be fitting abalone rosettes to my guitars but for the fact that the shell blanks are now unavailable from my usual U.S. sources. Perhaps that's a good thing: the radial designs I've adopted make a welcome and attractive change - at least I think so!

Routing the rosette channel

Dremel rotary tools attract criticism from some quarters due to their questionable robustness (this one is my third), but when combined with one of Stew-Mac's soundhole jigs and their router base, they're well suited to the task and I'm able to achieve a near-perfect fit of the rosette and the adjoining purfling rings. If there's a secret to success, it's in exercising patience and "sneaking up" on the final channel width in tiny increments, checking the fit of the rings after each cut until they slip into the channel with light pressure.

Dry-fitting the rosette and purfling rings

Once the rosette has been glued in place and allowed to dry, I feed the top through my drum sander until the rosette and the rings are at the same level as the top. I can easily check when I've arrived at that point by holding the top at an angle such that the the scratches left by the sander are clearly revealed against the light from the workshop door. I want to see continuous scratches along the full length and across the full width of the top, including the rosette. Once that's achieved, I bring the top to the desired thickness using the drum sander to remove material only from its inner face.

The zebrano rosette - glued and levelled

Click on any of the images for a closer look.

Cheers

Pete

Guitars for Sale - Perhaps!

2011-06-18T09:43:00.011+08:00

Either through ignorance, foolishness or a surplus of enthusiasm, I was only too keen to offer my early guitars for sale - thankfully, none of them have come back to haunt me! I've often wondered what became of the instruments I sold so many years ago, so it was with pleasant surprise that I received an email from a past "customer" who discovered this blog and decided to get in touch - thanks Laurence! It was great to hear from him, but I was a little startled to hear of his continuing affection for the guitar I built him - now more than ten years ago - given the degree to which the quality of my guitars has improved over the intervening years and how those first few instruments must suffer - quite naturally - by comparison to more recent efforts.

Frequent "reality checks" in the years since I built Laurence's guitar have served to keep my feet on the ground and have convinced me of the wisdom of building instruments for my own use, or for friends and acquaintances free of charge. It's a cautious approach that's allowed me to gather a much better array of jigs and tools and gradually improve my skills to a level comparable to other emerging builders. If you've followed this blog over the past couple of years you'll know that improving the standard of my finishes has also been a major factor in my decision to prolong my self-imposed apprenticeship.

Perhaps the two guitars I've recently commenced herald a new era and will give me the renewed confidence - hopefully deserved this time - to offer my guitars for sale. Both are modelled after Martin's iconic "Orchestra Model" (OM) series of instruments and feature combinations of East Indian Rosewood/Sitka Spruce and Claro Walnut/Redwood respectively.

If there's even a shred of truth in what's written about the tonal characteristics of the various wood species, the finished instruments will be worlds apart when they're eventually equipped to sing. Assuming I work on the instruments concurrently and complete them at the same time, I'll be well placed to make useful comparisons and judgements.

Cheers
Pete

The Fingerstyle Guitar - Progress Report #1

2011-06-17T18:04:00.004+08:00

By necessity, progress on all of my instruments takes place in fits and starts and typically drags out over many months - or longer! It's been especially difficult lately to find large chunks of time to devote to guitar building, although I can't complain too loudly: one of the reasons has been a leisurely three-week trip exploring Australia's east coast between Melbourne and Sydney - a long-awaited and enjoyable break from the normal routine.

Diversions and distractions aside, I have managed to spend some time on the claro walnut/redwood guitar I discussed in a recent post. The back is complete, the sides are bent and, after stealing a few hours away from my day job through the week, I've managed to join the halves of the redwood top and fabricate a zebrawood rosette. If all goes to plan, I'll inlay the rosette and thickness the top over the coming weekend. The really fun part - bracing and tuning the soundboard - will follow.

Cheers

Pete

Hot Hide Glue

2011-06-15T20:48:00.012+08:00

In an effort to find out first hand why so many luthiers favour the use of hot hide glue when modern alternatives are so readily available, I've finally ordered (and received!) some high clarity 192 gram-strength hide glue granules from the U.S. I'm sure my Titebond, epoxy and superglue will remain indispensable for many tasks, but I'm keen to introduce this most ancient of glue types into my building process, particularly when it comes to attaching braces to instrument soundboards and backs.

My initial order was intercepted by Australia's occasionally-vigilant quarantine service and ultimately destroyed by them (despite my protestations), but it seems they were distracted by other matters while my second order was entering the country. I'd be feeling a little guilty right now for having circumvented our quarantine laws, except for the fact that other Australian builders report that their shipments are routinely inspected by quarantine personnel before being sealed up and sent on their way without a fuss. If one-pound packages of hide glue posed any real threat to national security I'm sure they would be confiscated on a more consistent basis!

It's been a long time since I've had any need for a baby bottle warmer; the cheap model pictured will see out its days as a handy glue pot.

Some useful links:
Frank Ford - Using Hide Glue
Luthier's Mercantile - Granular Hide Glue
Wikipedia - Animal Glue

Cheers
Pete

The Fingerstyle Guitar - Prototype #1

2011-06-03T18:39:00.015+08:00

Not so long ago, I started a thread on the Acoustic Guitar Forum seeking opinions as to the ultimate fingerstyle guitar with respect to design features and materials; there were some interesting and very informative responses. I have to concede that in the past I've erred in seeking out construction tips from other builders to the exclusion of the views of the people who really matter - the players! It seems to me that the Acoustic Guitar Forum is frequented more by guitar players than by guitar builders, so the opinions offered were particularly illuminating. With the benefit of that feedback, I'm setting out to build the best fingerstyle guitar I possibly can within my own limitations and accepting of course that opinions as to what such an instrument might look and sound like will vary markedly.

Perhaps it's my own slightly flawed tendency to focus on the visual aspects of the guitar which made some suggestions stand out from the pack, but within the comments I received I noted an emphasis on the ergonomics of the instrument I was proposing. As well as responsiveness and lightness, a slightly wider string spacing at the bridge and a wider nut stood out as worthwhile features on a guitar destined as a fingerstyle instrument. Depending on how adventurous I'm feeling, I may attempt an arm bevel for the first time too.

Where wood choices are concerned, I sense a preference for the responsiveness and warmth of cedar or redwood soundboards, while for back and sides, walnut seems a popular choice, perhaps because its higher damping and tendency towards shorter sustain results in greater clarity and separation of notes when in the hands of a fingerstyle player. That being my summation of the opinions offered, I'm opting for a combination of claro walnut and redwood together with the wider string spacings generally preferred by those who responded. I'm favouring my take on the ubiquitous Martin OM body shape together with that model's 25.4" scale length.

I hope you'll join me as I begin my quest for the "ultimate" fingerstyle guitar. If the outcome is anything less than brilliant, I can always laugh the offending instrument off as "a prototype" in an attempt to salvage some self-respect!

Cheers

Pete

A Belated Gift

2011-04-21T20:19:00.014+08:00

If first impressions count for anything, there are a lot of things to like about this guitar which I strung up for the first time last weekend. I'll let it settle for a while before I make final nut, saddle and action adjustments, but even in its current unfinished state I'm able to play it and assess its tonal potential. I look forward to enjoying the full experience - however briefly - before I deliver it to its new owner.

There were more than my usual number of blunders along the way and I'm still refining my finishing technique, but overall I'm pleased with the outcome. The minor cosmetic flaws are disappointing, but after riding out the obligatory post-build period of self-recrimination, I'm now able to look beyond them and enjoy the fact that the sound of this guitar surpasses anything I've built previously. My hope is that where bracing and tuning of the soundboard is concerned, what I've achieved with this guitar signals a permanent leap to the next level.

The guitar is a gift to a very patient musician friend in Melbourne. Maurice is an old rocker with a soft spot for Marshall stacks and Gibson Les Pauls, however, I hold out some faint hope that he'll be impressed enough with this guitar to suppress his natural tendencies and learn some more subdued acoustic pieces. The message will be clear when I present it to him: if he's inclined to mount a humbucker in the soundhole and plug into a wall of Marshalls, I'd rather not know about it!

Soundboard: Engelmann spruce

Back and sides: East Indian rosewood

Neck: Queensland maple

Fretboard and bridge: ebony

Bindings and trim: koa
Rosette and fretboard inlay: green abalone

Tuners: Schaller mini

Fretwire: Gold "Evo"

Cheers
Pete

It's All About the Music!

2011-04-04T11:40:00.010+08:00

As a would-be luthier, it's easy to lose sight of the fact that the guitar is a means to an end rather than an end in itself, and that as a builder of musical instruments, the role I play is to facilitate the making of music. Accepting that I gain immense enjoyment from my contribution to the process and that my efforts are worthwhile in their own right - at least at a personal level - ultimately it's the musician who (hopefully!) creates the real magic.

I was privileged to experience some of that magic on Friday night when Tony McManus was in town. While I don't hold out much hope of ever having my guitars in the hands of the likes of Tony McManus, seeing a player of his calibre play in person strengthens my resolve to build the best guitars I possibly can in the hope that I can contribute in some small way to the creation of beautiful music.

Coincidentally, it was at this same venue that I watched the owner of my one and only commission so far - a 12-fret 000 - put his new guitar through its paces. That was some years and several guitars ago, but the experience lives on in my memory as the highlight of my guitar building "career" to date. Perhaps, one day, I'll have the opportunity to repeat it!

Cheers

Pete

Hand Tools: Out With the Old, In With the New

2011-03-27T17:00:00.004+08:00

I've known for a long time that guitar building will be an activity I'll pursue until failing eyesight, a wayward bus or the grim reaper himself finally put an end to my efforts. Despite that certainty, I've always had great difficulty parting with my hard-earned cash to build a collection of high quality hand tools - second-hand shops and flea markets have been the source of many of them until recently.

I've justified my tight-fisted attitude by reasoning that spending five times as much on a decent hand plane, for example, would be unlikely to result in a corresponding five-fold improvement in the standard of my instruments. While there's still truth in that argument at a superficial level, thinking a little more deeply on the subject leads me to conclude that there are other more subtle benefits to owning quality tools beyond their ability to perform their intended function so much more effectively than the poor substitutes I've made do with in the past.

In fact, finally clicking the "Buy Now" button on a set of LMI's chisels and a couple of Veritas hand planes - a low-angle jack plane and a #4 smoother - has been beneficial on many levels. The simple fact that my chisels and planes are now of a much higher quality has instilled a sense of pride in their ownership - a new and pleasurable experience! That in turn has added to my enjoyment of the job at hand which in itself can only have a positive effect on the standard of my work. I might also add that acquiring quality tools and experiencing the warm glow their ownership brings has provided the incentive to develop a much more disciplined approach where sharpening is concerned - I've been pretty lazy in the past on that score.

When I'm about to undertake a task demanding the utmost care and attention to detail, I find that clearing my workbench of its usual accumulation of tools and firing up the shop vacuum seems to unclutter my mind as well as my immediate work area; I seem better able to concentrate and my chances of success with whatever task I'm about to begin seem vastly improved as a result. I'm finding that the joy of using a well-tuned, good quality plane or a sharp, finely made chisel is having a similarly positive effect on my attitude and ability to focus. Any doubts I might have had brought about by the not-insignificant cost - including the predictably horrendous shipping charges from the U.S. and Canada - are fading rapidly. Besides (I tell myself!) my amateur status shouldn't stand in the way of my pursuit of professional results.

If there's a downside to all this - other than the hit my wallet has taken of late - it's that I can no longer blame poor quality tools for any work I judge to be less than perfect!

Cheers

Pete

Claro Walnut - a Musical Thud

2011-03-04T16:20:00.006+08:00

After joining and thicknessing this walnut back set it was difficult to muster enthusiasm when assessing its resonant qualities, however, the attachment of braces has elevated the response when tapped to a more pleasing musical thud!

Unlike the much-prized rosewood species, claro walnut isn't known for its ringing glassy tap-tone, but with this guitar destined for a fingerstyle player, that's not necessarily a desirable trait anyway. When discussing fingerstyle guitars, popular opinion seems to be that each note should do its thing then get out of the way relatively quickly to make way for those to follow. With a relatively high damping factor, claro walnut supposedly satisfies that requirement well by limiting sustain - or at least not contributing further to it. It's also said to impart little of its own sonic flavour to the completed instrument leaving the top to produce it's signature sound unhindered.

Paired with the tonal warmth and richness characteristic of a redwood top, I'm hopeful that the guitar this back is destined for will be as successful as my previous claro walnut/Engelmann spruce instruments.

Cheers

Pete

Slow and Steady Wins the Race!

2011-02-20T19:14:00.014+08:00

I often rue the fact that I have insufficient time to spend on my hobbies, but the picture below suggests otherwise. The secret seems to be in looking ahead, determining as best as I can what spare time I might have on my hands and planning in advance how best to make use of it.

The back and soundboard halves were joined and thicknessed on separate days some weeks ago, while the braces, bridge patch, cross-grain back reinforcement and headblock have been laying around in readiness having been prepared in short bursts of activity over the past few months.

With higher humidity on several days over the last two weeks, the dehumidifier in the spare room has been running continuously and I've been able to maintain a relative humidity of around 45% - ideal for gluing braces to the soundboard and back. The temperature in my workshop has been bearable too, and the neck I began yesterday reached its current state of completion this afternoon. I'm on a roll!

Cheers

Pete

Voicing the Top - Intuition and Technology

2011-02-13T16:34:00.010+08:00

Shaving the soundboard braces to bring out the guitar's tonal potential is one of the more intuitive and mysterious aspects of guitar construction. For me, it's also one of the more tactile and enjoyable stages when the use of hand tools is mandatory and the senses come strongly into play. A cycle of tapping, flexing and brace shaving is involved, with a somewhat nebulous goal in mind despite having read everything I can on the subject!

Unfortunately, my hobby builder status dictates that it's often many months after voicing a top then going on to complete and evaluate the instrument before I'm able to repeat the exercise - hardly an ideal situation in terms of being able to build any sort of muscle memory or draw meaningful conclusions. The pertinent questions whose answers seem elusive in terms of being able to adequately articulate them are:

What did the top feel like as I flexed it, i.e., how much resistance was there when bending it across the grain and with the grain?
How did the top ring as I tapped it and how was the response influenced by the way the top was held or suspended and where it was tapped?
What was the correlation between those very subjective assessments and the success of the completed instrument from a tonal perspective?
To what extent did the materials, density and stiffness of the guitar's other components combine with those of the top and contribute to the outcome?

As I review that list of questions, it strikes me that the challenges they pose seem almost insurmountable. It's obvious that relying on my memory from one instrument to the next isn't a satisfactory approach given the subjective nature of the assessments involved and how infrequently I'm able to repeat this part of the process.

Perhaps the use of technology offers a way forward and can lend a degree of objectivity to what would otherwise be limited to some vague, transient sensory experience. Measuring top deflection both parallel to and across the grain prior to gluing the braces, photographing the top bracing and noting brace heights, recording tap tones with a decent microphone (or perhaps one of the hand-held Zoom recorders) or even videoing myself as I hold the top and tap it seem likely candidates as I seek to minimise the guesswork involved in the voicing process and develop a baseline for subsequent instruments. Or perhaps I should learn to trust my senses and develop a greater appreciation for the delightful uncertainties inherent in wooden instrument construction!

Cheers
Pete

Glue Clean Up

2011-02-11T20:01:00.009+08:00

With the advent of the soundport, the standard of workmanship inside the guitar body is more easily scrutinized and there's perhaps an even greater incentive to clean up surplus glue as the various component parts are assembled - not that I've neglected this previously. If some vintage instruments can be taken as a guide, it seems this wasn't always a priority, even for well-respected manufacturers. Times change though, and as I inspected a new Martin in a local music shop not long ago, I must say I was impressed by the meticulous attention to detail within the guitar body including the fact that all traces of excess glue had been carefully removed from the intersection of the back plate with the linings and back braces. I vowed then and there to emulate this in my own instruments to the best of my ability in recognition of the fact that it's often the little things that make a big impression.

There are several approaches to cleaning up excess glue once clamping pressure is applied to a freshly-glued joint. Regardless of the method used, I always try to plan ahead and give some thought to the arrangement of clamps to ensure unhindered access to glue squeeze-out after they're in place. I'm also careful not to apply an excessive amount of glue in the first place. A 1-inch foam roller is helpful in that regard, with the added advantage that an even coverage of glue is more quickly and easily achieved.

I know that the preferred approach for many builders, whichever glue is used, is to leave glue squeeze-out undisturbed, letting it partially set or gel before attempting to remove the excess. I use Titebond for the majority of gluing tasks, and find that a flattened plastic drinking straw with the end cut at something like a 45 degree angle is a good first step towards removing unwanted glue as soon as clamps are in place. This approach works particularly well when gluing braces to the soundboard or back. The straw is pushed cut-end-first along the freshly-glued joint and much of the surplus glue finds its way inside the straw which is then discarded. It helps of course to have several pre-prepared sections of drinking straw on hand. Chisel-shaped slivers of spruce or cedar, moistened Q-Tips (cotton buds or ear buds) or a moistened sponge can also be useful as a follow-up and, using a combination of these methods, it's usually possible to remove every last vestige of excess glue without compromising the joint itself.

When gluing braces to the back and soundboard, I exercise patience and generally glue one - or perhaps two - braces at a time. Not only does this slow and steady approach give me ample time to clean up after myself, but I have the luxury of a clear view and unobstructed access to squeeze-out.

Another strategy which contributes to a clean look inside the guitar body is to attach the rim assembly to the back first, rather than to the top. I find it helpful to have a second chance to tidy things up before the top is attached and while the various nooks and crannies which will remain visible after final assembly are still easily accessible.

Cheers

Pete

Two Rosettes

2011-02-01T20:23:00.004+08:00

The finished rosettes:

I'm pretty happy with them both, and they provide an attractive alternative to my more usual abalone rosettes.

Click on the image for a better view.

Cheers
Pete

A New Rosette

2011-01-24T11:56:00.009+08:00

This rosette is a departure from the abalone versions I've recently installed. It's a simple radial design in Macassar ebony which I hope will work well in the visual sense; the final verdict will have to wait until I can marry it with the guitar's other decorative elements and see it as part of an overall design.

Dimensions marked on 1/8" MDF

Sliced and diced: ready for tapering

Tapering the wedges on the disk sander

Wedges tapered and glued

Routed to size - a spiral down-cut router bit keeps things tidy

Ready for installation in a redwood top

I have two of these rosettes ready to install along with their edge purflings. I'll post pictures when they're done.

Cheers

Pete

Lessons in Finishing

2011-01-20T13:15:00.009+08:00

Having completed only a handful of instruments with sprayed finishes, it's not terribly difficult to identify flaws and aspects of the process I've yet to come to terms with. Having said that, it helps to keep things in perspective and remind myself occasionally that the perfect finish - if there is such a thing - is an impossible dream for us mere mortals, a fact apparently acknowledged by many U.S.-based builders who happily farm out the finishing of their instruments to a professional. I'm sure the health and safety aspects of working with solvent-based materials play a significant part in that decision too. Down here at the bottom of the world, however, I'm left with the task of identifying problems with my technique, improving my finishing processes, finding materials that suit my situation and hobbyist status and developing the most effective means to combine and apply them. Although it's been a laborious and sometimes frustrating process, I'm cautiously optimistic about my next guitar - but then I always am!

I've made some mental notes of late where finishing is concerned:

Do a thorough job when pore-filling. At this point in time I'm using epoxy, as do many others. Aside from its effectiveness in filling the pores, I like the way it enhances the figure and colour of the wood it's applied to. Briefly described, pore-filling consists of applying the epoxy to the wood with an old credit card or spatula, then removing as much as possible from the wood's surface, leaving epoxy only in the pores. It often takes several sessions, allowing the epoxy to cure and sanding off dust nibs and ridges before the next application, before all visible pores are filled, but it's worth the extra effort given all the hard work that's preceded it.
Wipe down cured epoxy thoroughly. A by-product produced as epoxy cures is something called "amine blush", a waxy residue that can have an adverse effect on subsequent coatings. Thankfully, a good rub down with a damp cloth, or one dampened with a mix of denatured alcohol and water is sufficient to remove it. From what I've read, it's worth spending a little extra on a good quality epoxy and applying it in a warm, low-humidity environment to reduce the impact of blushing. The manufacturer of the boat-building epoxy I use contends that their product is not prone to amine blush, but I tend to give it a precautionary wipe down anyway as added insurance.
Find a compatible sealer. Oily species such as rosewood can be particularly problematic and can adversely affect or even prevent curing of top coats. It's worth experimenting with sealers or barrier coats to find one compatible with epoxy and your chosen top coat material. While some builders sand the epoxy pore fill back to the wood, in which case an effective sealer becomes particularly vital when using any of the oily wood species, I choose to leave a thin layer of epoxy on the wood - excluding the soundboard. The epoxy serves to lock in any oils present in the substrate and the task remaining for me has been to find a effective product to act as a tie-coat between the epoxy and the top coats of KTM-SV. Adhesion of my top coats has been a recent concern, but hopefully I've identified a compatible set of finishing products as I described in an earlier post.
Find a suitable top-coat. Having set myself the long-term goal of selling my instruments, I've pondered the various features that a prospective purchaser might commonly be looking for. A durable, high-gloss finish is one them, and is one aspect of instrument building that continues to test me, particularly as I've vowed to avoid solvent-based materials such as the much-used but far more hazardous nitrocellulose lacquer.
Drop-fill early. Any small gaps in the bindings are evident once the first top coats are applied. It's worthwhile dealing with gaps and pin holes while there are plenty of remaining top coats to even out these repairs, the caution being that with only a couple of coats of finish in place, extra care needs to be taken so as not to sand through to the wood when levelling.
Level sand with the finest grade of abrasive paper which will get the job done, i.e., top-coats are necessarily thin and remnant scratches from coarser grades of paper are difficult to fill. With practice, sprayed finishes shouldn't need much in the way of leveling and, as I've become more comfortable with the settings on my spray gun, I've not found it necessary to level sand with anything coarser than 600-grit.
Final level sanding of the cured top coats can't be rushed, i.e., don't be in too much of a hurry to crank up the buffer! Patience and a generous helping of elbow grease are pre-requisites as the instrument is wet-sanded in readiness for final buffing.
Be careful when sanding the edges of the guitar, and especially so around the headstock, where it's easy to "roll-over" an edge with the sanding block and remove more finish than is necessary or, heaven forbid, sand through to the wood. I haven't sanded through yet, but I'm keenly aware of the potential to do so.

Cheers

Pete

Continuous Improvement - a Hard Road

2011-01-01T10:51:00.011+08:00

I tend to be hyper-critical of my own work, so it's gratifying to be able to identify at least some aspects of my instruments which I have difficulty finding fault with. Perhaps after 20 years of trying I've simply had enough practice, or perhaps as I've slowly accumulated a decent collection of tools and equipment, developed a range of useful jigs and constantly reassessed and refined my processes, a satisfactory outcome is now more likely.

Now that I've finished congratulating myself, I might add that there's plenty of scope for improvement in several important areas including fretting, setup and finishing. Even more significantly, having any real control over the tone of the finished instrument - except in the broadest sense - seems the most formidable challenge and is one reason I'd be reluctant to take on commissioned work should I ever decide I'm ready to sell my instruments.

An important part of the process of continuous improvement is an dispassionate self-appraisal of my work, involving a comparison of actual results with the work of others and the benchmarks I've set for myself. If my own personal vision of perfection is a valid goal - as it almost certainly should be - it helps to be mindful of the old conundrum involving travel: if we manage only to halve the remainder of the journey each day, we'll approach but never quite reach our target destination. It's a useful metaphor to reflect on when striving towards mastery of any skill; the parallel where my guitar building efforts are concerned is that rapid progress seemed far easier to achieve as I began this adventure, but as time has passed, improvements in the quality of my work seem less significant and more infrequent and difficult to achieve. I do wonder at times whether it's the challenges I constantly confront that form an important part of lutherie's appeal!

While I'm certainly in a position to cast a critical eye over the standard of my own workmanship with a reasonable degree of objectivity, my own limited playing skills will stand in the way of any useful self-critique where tone and playability are concerned. Bearing in mind that it's the views of the guitarists I build for that should be of primary concern, I really do need to seek constructive criticism from skilled players if I'm to make progress with those all-important aspects of the craft. Soon, perhaps, I'll hunt down a willing local participant with that goal in mind.

Cheers

Pete

Grafted Coatings' KTM-SV - A Sticky Problem

2010-12-20T19:25:00.012+08:00

With two guitar necks and a body almost ready for finishing, it's an ideal opportunity to refine my spray finishing techniques as well as experiment with a new seal coat material.

As I've reported previously, I'm pretty happy with Grafted Coatings' KTM-SV, the finish material I've used on my last two guitars, however, as I removed the finish in readiness for gluing the bridge in place on both guitars, I was a little concerned by the poor adhesion of the top-coats to the shellac beneath it. Shellac is well known as a material that readily sticks to almost anything, however, it seems the same can't always be said for the adhesive properties of other coatings when applied to shellac. Most notably perhaps, shellac adheres well to epoxy, but epoxy cannot be used on top of shellac. Go figure.

A recent thread on the Official Luthier's Forum discussed this issue and attracted some interesting responses. It's comforting in a way to read that others have had similar experiences and are also looking for solutions. It's also pleasing to see that Grafted Coatings themselves are taking a keen interest and have volunteered to prepare some test panels with a view to recommending a suitable sealer for their KTM-SV product.

I'm looking forward to Grafted Coatings presenting their findings, but in the meantime, I'm keen to try a two-pack polyurethane barrier coat manufactured by Ilva which luthier Randy Muth uses and recommends. I'm pleasantly surprised to have discovered a local source for Ilva products and relieved that the distributor - who commonly deals in commercial quantities - could be persuaded to decant a couple of litres each of the resin, hardener and thinners for me.

If I have any qualms, it's that I'll be reverting to use of a solvent-based product when it was the safe, environmentally-friendly aspects of KTM-SV which attracted my attention in the first place. Thankfully, use of this product is likely to be limited to two light coats, and with the usual precautions of good ventilation and a twin-filter respirator with vapor cartridges, I'm prepared to give it a trial run.

Cheers

Pete

Buy Now!

2010-11-24T20:13:00.002+08:00

It's been a long time coming, but with the Australian dollar at last reaching parity with the U.S. dollar (and predicted to climb even further), the parcel delivery van has been an increasingly frequent visitor of late. With such a strong local currency at present, Australian exporters are feeling the pain, but as an importer of "must have" guitar-building tools and exotic woods, I'm in my glory.

For too long, as my finger hovered uncertainly over the "Buy Now" button on the Allied Lutherie or Luthier's Mercantile web sites, I was forced to add up to 50% to the advertised U.S. price as I made a rough conversion to my own currency - and that's before I'd factored in those truly horrendous international freight charges. Often, I'd indulge in a little harmless fantasy and fill my online shopping cart and then, after a moment or two to savour the experience, grudgingly click the "Empty Cart" button after reality had kicked in and I'd calculated the final cost!

East Indian Rosewood

I've never been one to horde wood, preferring instead to order materials to satisfy immediate needs, but after my recent purchases I must admit it's nice for a change to be able to pick and choose from the growing collection of soundboards and back and side woods awaiting my attention. I can see why wood acquisition can become an addiction for many builders!

Cheers

Pete

Routing the Saddle Slot

2010-11-16T22:03:00.020+08:00

None of my jigs are particularly attractive, polished or professional, but they're certainly functional and take the guesswork and inconsistency out of many tasks.

Routing a slot in the bridge blank into which the bone saddle will be fitted is one job I've given over to the ugly but effective jig pictured below.

The Macassar ebony bridge blank is affixed to the base of the jig using double-sided tape (what would I do without it?); the blank's positioning isn't really critical. The blank is bedded down with a few taps from a soft-faced hammer which more than adequately secures it for the duration of the process - the tape is tenacious stuff!

As you can see, two adjustable guides sit atop the jig and, with the plunge router riding snugly between them and the router bit sitting just proud of the wood surface, are adjusted so that the bit will accurately track the line of the saddle marked on the bridge blank.

I rout the slot in several passes, each one a little deeper than the last, until I hit the depth stop set on the router body.

I'm tempted to add sliding stops to either end of the jig to limit the router's travel, but for now, a couple of strategically positioned panel pins serve this purpose well enough, which perhaps explains why I haven't been in any great hurry to make that modification - I'd rather be building guitars than building jigs.

I'll show the next stage of the process in a future post.

Cheers

Pete

Eye Strain Reduced!

2010-11-06T13:24:00.003+08:00

For making marks on dark woods such as rosewood and ebony, I use these white ballpoint pens which I discovered at an art supplies store. They're a vast improvement over the graphite pencils I made do with for so long.

Cheers

Pete

The Flat-Top Guitar That Isn't

2010-11-02T15:28:00.030+08:00

With some exceptions, steel-string acoustic guitars - often referred to as "flat-top" guitars - actually have arched or domed backs and soundboards, the advantage of which is arguably more structural than tonal. There are those who would argue that where soundboards are concerned there's little benefit in introducing an arch, but I think it's widely accepted that a domed top is better able to flex with variations in humidity thereby reducing the chance of cracks developing over time.

The mating surfaces of the various braces attached to the back and soundboard are curved in such a way that the dome is maintained in the finished instrument. Typically, the top assumes the shape of a section of a sphere having a 25 foot radius, while a 15 foot radius is commonly used for backs.

The following sequence of photos shows the method I use to shape the braces:

After the brace stock has been thicknessed to 7mm, I pencil the radius onto the brace blank using the appropriate acrylic template. In this case, I'm shaping the braces for the guitar back.

A 12-inch disk sander makes short work of the excess wood outside of the pencil line and it's surprising just how accurately the curve can be defined at this stage. A shop vacuum hooked up to the sander takes care of the wood dust pretty effectively.

With very little additional effort, the final arching of the brace can be established. Here, I'm using a hollow form whose radius matches that of the finished brace. Using 180-grit and 240-grit sandpaper in turn, the radius is accurately sanded into the brace. The scrap of wood held in place by my right hand helps prevent the brace from rocking sideways as it's sanded.

The finished back braces, ready for gluing.

Cheers

Pete

Joining the Back and Top Plates

2010-10-31T22:35:00.057+08:00

Preparing the back and soundboard halves for gluing is a relatively easy but critical step in guitar construction. Many luthiers use a traditional shooting board similar to the one pictured here. The back or soundboard halves are placed flat, one on top of the other, with the edges to be joined overhanging the ledge slightly; the plane is pushed along the length of the overhanging plate edges.

My own take on this has been to build a shooting board in such a way that the plates to be joined are held vertically between two cork-lined jaws as the picture below shows. The top or back plates are clamped lightly and accurately aligned before the jaws are fully tightened. Truing the edges then takes place with the plane guided by the vertical fence, with pressure applied from above and the plane held in the familiar and more controllable upright position. The advantage of this configuration for me is that, once they're firmly clamped, the plates are immobilised and I feel I'm able to apply more even pressure than a more typical shooting board would permit. To ensure an accurate cut, my trusty old wooden plane has been fed through the drum sander to true up the side which bears against the fence.

A few judicious strokes with a sharp plane blade are generally all that's required to achieve the perfect joint, after which, the halves are glued together using the jig shown below. As you can see, wedges are tapped into place to apply the necessary clamping pressure. The underside of the blocks is faced with 80-grit sandpaper which reduces slippage once the wing nuts are tightened and the wedges are tapped home.

Cheers

Pete

Some Final Observations on KTM-SV

2010-10-23T09:17:00.024+08:00

I realise I've banged on about Grafted Coatings' KTM-SV water-based finish a bit over recent months but, as a final word on the subject, it's probably worth reviewing what I've read or found out for myself for the benefit of others who find themselves facing the same challenges I did with the finishing process.

From memory, I was alerted to this finish by Rolfe Gerhard’s article “KTM-SV – An Overlooked Finish”. The way Rolfe described it, Grafted Coatings’ KTM-SV sounded like the safe, environmentally-friendly finish material I’d been vainly searching for to that point, possessing most of the positive attributes of the other commonly used water-based products, with some important differences. Grafted Coatings’ web site describes it as “a waterborne, oil-modified, self-crosslinking urethane”, which immediately separates it from the better known waterborne acrylics.

On the plus side, it’s reportedly harder than the likes of Target Coatings’ EM6000 or Grafted Coatings’ other instrument finish, KTM9, although how that’s been determined with certainty I’m not quite sure. Also, not having an acrylic base as they do, it doesn’t display any of the blue cast some report with those products. For me, however, the most telling statement in Rolfe’s article is that he’s had instruments in the hands of players for two or three years and no problems have arisen in that time. For my own peace of mind I wish it were longer, but I’m comforted by that information nevertheless. For me, this is the acid test in terms of any new or newly adopted product’s suitability as an instrument finish. How many stories are there of instruments finished with KTM9 developing bubbling or sticky necks over time for instance? KTM9 still has its fans, but I think it’s fair to say the enthusiasm for that particular product has diminished over the past few years, due in part perhaps since prominent advocates such as Mike Doolin and Charles Fox have reportedly jumped ship and turned to polyester and nitro respectively. The disappointments with U-Beaut’s original Hard Shellac are well documented and, although it’s been reformulated, I’m still unconvinced of its suitability given my recent experience with it as a sprayed finish – French polishers (and Australian ones for that matter!) may have more luck. In any case, I don’t think it’s proven itself over a long enough period to be considered seriously, particularly if you’re as cautious as I am and share my view that warranty work is bad advertising, even if it’s expertly carried out.

Because I avoid mineral spirits (turpentine) whenever possible, another plus for me is that unlike other waterborne products, KTM-SV can apparently be wet-sanded using water as the lubricant. In his article, Rolfe says that witness lines buff out invisibly, which I’m able to confirm with greater conviction since I steeled myself and ordered a buffing arbor from LMI in the U.S. Used together with two grades of Menzerna buffing compound, buffing is now an easy task, and the gloss I’m able to achieve effortlessly is pretty impressive. My wallet may be lighter, but my finishes have improved out of sight as compensation.

Of course, with any finish material there are trade-offs and compromises and KTM-SV is perhaps no different in that regard. One of KTM-SV’s supposed disadvantages is that, unlike Target’s EM6000, once it’s cured, subsequent coats don’t burn into the preceding ones meaning that invisible finish repairs are difficult to achieve. I’ve come across some conflicting advice, however, which says that rubbing the area to be repaired with acetone or lacquer thinner softens the finish enough to allow an invisible repair, but I have no first-hand experience where that’s concerned and can only repeat here what I’ve read elsewhere. Less significantly in my view, it’s said that it can’t be buffed to as high a gloss as nitro, although I’m pretty happy with the gloss level on the guitars pictured. The only other real negative - which I'm all too used to living in Australia - is that freight from the U.S. is more costly than the material itself.

The guitars pictured in my last two posts were finished with KTM-SV top coats over epoxy pore fill and three seal coats of de-waxed white shellac. I followed the finish schedule described by Randy Muth in a thread on the OLF, whose prescription is for six coats per day over two days, with the exception of the soundboard which receives two coats fewer for a total of ten, i.e., only four coats on the second day. Following Rolfe’s suggestion, I added 30ml of distilled water to my quart tin of KTM-SV which seemed to help with flow-out and leveling, although it’s also possible that the coats began to lay down more smoothly for me as my novice spraying technique improved; by the time I applied the last top coats on the second of these guitars, it was laying down beautifully, to the extent that I was able to begin my level-sanding with 800-grit paper.

Interestingly, Rolfe also remarks that there’s very little shrink back as the finish cures, however, I notice that minute ridges corresponding to the grain lines are evident on both tops; in fact, it looks a lot like a typical thin nitro finish which isn’t necessarily a bad thing given that for many, nitro is still the standard by which all other finishes are judged. As best as I could determine with dial calipers, my ten coats on the soundboard measured around 0.1mm, or 4 thou in thickness after leveling and buffing – a very crude guide to be sure, but nevertheless helpful in the absence of any more accurate means of measurement.

At some point I may try Target Coatings’ EM6000 (Stew-Mac’s Colortone Waterbase Lacquer) purely for the sake of comparison, but for the foreseeable future I’m a KTM-SV convert, and greatly relieved to have at last a found a finish product which allows amateurs like me to produce near professional results without the bother and expense of a spray booth, explosion-proof fan, etc. I know I could cross my fingers and shoot nitrocellulose in the back yard as many others do, but I’ve been there and done that and as I’ve grown older, a little wiser, and a lot more conscious of health and safety issues, I’ve decided not to repeat that experience and expose myself and others to the attendant risks. Like a reformed smoker, I’m still tempted at times to ignore the risks and revert to past practice, but I’m confident that good sense will prevail on both counts!

Some relevant links:

KTM-SV – An Overlooked Finish

KTM-SV Finish for Wood

Official Luthier's Forum discussion

Cheers

Pete

Notable Firsts

2010-08-28T08:43:00.064+08:00

This is a guitar project I've had very little time to work on lately, but with the Australian blackwood/Sitka spruce triple-O featured in my last post about to head off to its new home, I delude myself with the notion that with one less guitar to complete, this East Indian rosewood/Engelmann spruce effort is somehow closer to completion too.

With a side soundport and a Florentine cutaway, there are some personal firsts for me with this instrument. This has also been my first experience using Grafted Coatings' "other" water-based finish, KTM-SV, which I've written enthusiastically about in earlier posts. KTM9, Grafted Coatings' previous foray into water-based finishes, was successful up to a point and still has its advocates, but there have been enough negative reports over the years that I eventually discounted it as I considered a switch to sprayed finishes. I think it's fair to say that in many people's experience it hasn't stood up well to normal wear and tear or, most alarmingly, to the corrosive effects of some people's perspiration. To date, I've read no reports of a similar nature regarding KTM-SV - fingers firmly crossed!

The soundport is an increasingly popular feature and proved a simple addition, which perhaps accounts for the fact that some professional builders offer it as an option at no additional cost. Adding the port is a relatively easy task which I completed once kerfed linings had been glued around the rim and the back had been attached to the sides. The guitar sides diminish gradually in depth as they approach the neck area, and it was easy to glue in a similarly tapered veneer laminate to wedge snugly between the linings as cross-grain support in the area of the port. I chose a simple oval soundport which was marked on the outer face of the side with the aid of a flexible plastic template and a white ball-point pen. I used my Dremel and a tiny circular saw blade to roughly cut through the side and the backing laminate well inside the line, then sanded to the line with the Dremel and a mini sanding drum.

The cutaway presented a more formidable challenge, with much head-scratching and several sleepless nights required before a plan of attack was formulated. Bending the cutaway section of the side on an electric bending iron was easy enough, but binding the point of the cutaway proved a little trickier; I chose the ambitious approach which was to mitre the joints in three dimensions. The outcome wasn't perfect, but having now negotiated the process more or less successfully, I can see ways to improve the end result next time around. Generally, it's only after I've addressed a problem and found myself unable to identify a potential solution that I become temporarily dejected and briefly contemplate other less taxing hobbies!

Cheers

Pete

Reaching the Finish Line

2010-07-16T20:41:00.056+08:00

I've made significant advances with many aspects of guitar construction in the recent past, but achieving a quality finish has proven to be a persistent frustration as well as one of the last major hurdles. It's especially pleasing then to be able to report that the finish used on this guitar - Grafted Coatings' KTM-SV - has proven to be a watershed where confidence in the standard of my guitars is concerned.

While there's still plenty of scope for further improvement of my skills and knowledge - most noticeably in the area of fretwork and setup - I'm quietly confident that my guitars are approaching a standard comparable to that of other fledgling independent builders. If I ever make the leap and decide I'm ready to sell my guitars, the prices I ask will of course reflect this cautious assessment!

Finding a finish product which works for me is cause for celebration, but rubbing it out to the high gloss that guitar owners expect has been yet another challenge. Thankfully, after taking the plunge recently and ordering a buffing arbor from LMI in the US, I'm pleased at last to be able to bid farewell to the more laborious hand-polishing methods. Not only was it an onerous task, but I was never entirely satisfied with the end result. With motor-driven buffing wheels and two grades of Menzerna dry buffing compounds at my disposal, the process is an absolute breeze and the gloss I'm now able to achieve reduces the pain of having purchased a hefty piece of equipment from overseas. International freight charges - as always - are a real headache!

I guess some vital statistics are in order:

Back and sides: Australian blackwood
Soundboard: Sitka spruce
Neck: Queensland maple
Bridge and fingerboard: ebony
Bindings: ebony
Frets: EVO gold
Tuners: Gotoh 510 minis
Rosette and fingerboard inlay: paua abalone
Finish: Grafted Coatings KTM-SV
Scale length: 24.9"

Click any of the photos for a larger view.

Cheers

Pete

Double-Standards

2010-03-04T15:54:00.006+08:00

What a strange set of standards we apply when it comes to wood. Where backs and sides and, to a lesser extent, soundboards are concerned, we are happy to pay a premium for colourful, unique or highly-figured woods. According to tradition though, components made from ebony must be jet black and are graded and priced accordingly. We can even buy dyes especially for the purpose of reducing interesting, streaky ebony to a boring, homogeneous black!

The ebony headplate pictured was rated as "second-grade" material, presumably because it wasn't boring enough. Make up your own mind!

I've applied a first seal coat of shellac on this neck and will spray another two before allowing it to cure overnight. Once the finish coats of KTM-SV have been sprayed, levelled and polished, I'm confident this ebony will look much better than second-grade!

Cheers

Pete

In Pursuit of a Glossy Finish

2010-01-14T11:09:00.039+08:00

Without access to a buffing wheel, it's a case of gritting my teeth and rubbing out the finish on this guitar using more tedious methods. It's a good workout if nothing else!

I was careful to level the finish thoroughly as the spraying of the 12 top-coats proceeded. As a result, it was a relatively easy task to carry out the final levelling with 800-grit wet-or-dry paper and water once the finish had been allowed to cure for a few days. To allow for the curvature of the guitar's surfaces - including the domed top and back plates - I wrap my abrasive paper around a small rectangle of cork floor tile. The cork provides a solid backing for the paper but has just enough flex to conform to the curves. I've had better results since I began sanding with the grain, the significance of which is that by sanding in one direction, the sanding scratches seem more easily removed by the grade of paper to follow.

Other water-based finish products require that mineral spirits (turpentine) be used when wet sanding, however, I detest turpentine for any application and it's a blessing that KTM-SV can be safely wet-sanded using water as the lubricant, - the proviso being that it's been given time to cure. It's become very clear to me that a little extra time spent sanding thoroughly through 800, 1200, 1500 and 2000 grit papers to remove sanding scratches before the polishing compounds are brought into play makes a high gloss much, much easier to achieve. If you noticed the large gap between 800 and 1200, it's only because my usual local sources seem to have run out of 1000-grit paper temporarily. Sanding is a tedious task, but I found that reaching for the polishing compounds too soon invariably saw me return to wet-sanding soon afterwards when polishing revealed remnant sanding scratches - there are NO short-cuts!

As I mentioned in an earlier post, I use Autoglym's 03B Fine Abrasive and 02B Ultrafine Renovator once I'm done with sanding. With limited experience with sprayed finishes, I'm still pretty tentative when it comes to levelling and polishing for fear of rubbing through the layers of finish to the wood and, although a random-orbital sander equipped with hook-and-loop Surbuf pads helps with the polishing to a degree, I've been careful to stay away from the perimeter of the guitar's top and back plates as well as the edge of the soundhole, the area of the side soundport and the cutaway region while using it. As a result, I'm left with the option of a cork-backed sanding block wrapped with a polishing cloth to rub out these areas. It's not a difficult job, but patience and persistence are valuable assets - ones I wish I had in greater measure!

Click on any of the photos for a larger view.

Cheers

Pete

Beautiful Blackwood

2009-12-31T09:06:00.076+08:00

Here are a couple of attempts to show a guitar-in-progress after I sprayed two coats of de-waxed white shellac this afternoon as a sealer and tie-coat.

Among the many significant milestones to be enjoyed during the building process, this must surely be one of the most satisfying - the ugly duckling is turning into a beautiful swan! There's still a long way to go before the transformation is complete, but it's at this point I tell myself I can see the light at the end of the tunnel and can look ahead eagerly to the end result of my latest collaboration with Mother Nature.

I visited Australia's south-east for the first time last year and was taken aback by just how common Australian blackwood (Acacia melanoxylon) is, however, trees yielding wood with the striking figure displayed here are altogether more unusual. The rippled appearance in the grain changes constantly depending on the direction of the light and the angle of view - no photograph can truly do this wood justice! There's little wonder it's become so highly prized in the guitar world both here and abroad for it's looks alone.

Just to demonstrate that its popularity extends beyond guitar enthusiasts, here's a shot of a brushtailed possum who had taken up residence in a blackwood tree next to our overnight camp in Victoria's Tarra-Bulga National Park.

Click on any of the photos for a larger view.

Cheers

Pete

Economies of Scale

2009-12-26T10:31:00.001+08:00

As my current marathon effort building several instruments at the same time draws to a conclusion, I've sworn never to repeat the exercise when I finally have a clean slate and I'm ready to begin the next one. As a part-timer, the building process is slow enough as it is and I've found it a little frustrating having to wait so long to enjoy the fruits of my labour when my limited time is divided between so many instruments.

Nevertheless, it's sometimes more efficient to work on a production run of components like these mahogany neck blocks, when preparing bracing stock or dimensioning and slotting the mahogany strips to be used as kerfed linings. The additional time involved isn't hugely significant and it's easier to fabricate them mindlessly with consistent dimensions when jigs are in place or machinery is set up and adjusted appropriately. There's the pleasing illusion of rapid progress to be enjoyed later on too when there's a ready-made stock of components on hand!

Cheers

Pete

New Rosewood Back and Sides

2009-12-12T15:59:00.019+08:00

Here's a recent acquisition which I hope to begin work on early next year, assuming I've managed to complete my current crop of guitars. As much as I've grown to love it, East Indian Rosewood can sometimes look a little bland and uninteresting, but in this case the colour variation is a little more pronounced than usual and I found myself unable to resist the urge to click the "Buy Now" button when I spied it on Allied Lutherie's web site! It should look terrific under a finish, and the tap-tone in its current raw state suggests that it has the potential to sound pretty impressive too.

East Indian Rosewood is something of a staple in the guitar-building world and, unlike some of the other rosewoods, is still reasonably priced and has a fairly secure future. I always smile when I see sets of this wood marked down to a lower grade when they're not exactly quarter-sawn or exhibit anything less than perfectly straight grain. Some of the other more coveted rosewood species are offered to instrument builders for astronomical prices even when they're flat-sawn or have been salvaged from stumps and have the wildest grain imaginable. The bar is obviously set pretty high for their Indian cousin!

Cheers

Pete

U-Beaut Hard Shellac - Once Bitten, Twice Shy

2009-12-11T14:39:00.017+08:00

I didn't want to die wondering whether U-Beaut's Hard Shellac could have been the answer to my finishing dreams and I experimented with it on this little Claro Walnut/Engelmann Spruce 12-fret double-0, destined for my own use. Having been distracted by other projects recently I've only just strung the guitar up and, although it's still a little tight and is yet to have its initial fret job and setup, it sounds very promising already. What's more, I love the way it looks - up to a point.

Reports from those who had used an earlier formulation of this finish were encouraging, but there were occasional angry mutterings about serious crazing which sometimes materialised weeks or even months after application. In response to criticism, the manufacturer added a plasticiser to the recipe and re-released the product, advertising the fact that it was now suitable for musical instruments. I certainly found it a dream to spray after reducing it 50/50 with denatured alcohol to a 2lb cut and, after waiting three weeks or so for it to fully cross-link and harden, I was able to rub it out to an impressive shine. I was an instant but cautious convert! My optimism was tempered by the recognition that any finish - particularly a shellac variant - has to prove its resistance to use and abuse over time before it can be declared commercially viable. With neither use nor abuse to blame in this instance, my hopes have been dashed already however and, after six months, the finish on the neck of this guitar shows the first barely discernible but unmistakeable signs of the same crazing which so frustrated (some) users of the earlier formulation. There's an equally faint suggestion of the same thing happening at the waist on one side and there's no telling if it will worsen or appear elsewhere over time. I must say, I'm not too upset though; it was a risk I was willing to take and at least it's answered the questions I had once and for all - in my mind anyway.

Interestingly, this Australian product has recently been added to the inventory of one of the leading U.S. lutherie suppliers and there's been a good deal of excited chatter about it on one of the on-line guitar building forums. Based on my very limited experience, I can only urge caution; either the additional plasticiser hasn't been entirely successful in curing the crazing problem, or skilful application is absolutely critical to success. Although I was at pains to spray thin coats, waiting an hour or so between them (it was a hot day), it just may be that the ambient conditions at the time weren't ideal, or that my rudimentary skills with the spray gun weren't up to the task. Perhaps those applying it as a french-polished finish will have better luck, but after this experience, I'm fearful that the results are likely to be unpredictable at best - not a recipe for good customer relations. For the time being at least, I'm inclined to stick with the water-based KTM-SV I discussed in my previous post.

Cheers

Pete

KTM-SV - The Bee's Knees

2009-12-10T09:52:00.002+08:00

As I'd hoped, the top coats of Grafted Coatings' KTM-SV went onto my OM beautifully, particularly after I'd added some distilled water to the finish prior to spraying. The advice I'd read suggested adding 1 ounce of distilled water to a quart of finish which equates to around 30ml for us metric types. I used approximately half of my quart tin which should leave enough for the Australian Blackwood/Sitka Spruce triple-0 waiting in the finishing queue.

Other than it being an opportunity to become better acquainted with my spray equipment, I learned that acceptable results are probably more likely when the temperature is lower and the humidity higher than it was on my first day of spraying. With the temperature climbing to around 35C through the day and the relative humidity sitting on 20%, I was probably foolish to have proceeded and it was difficult to achieve the wet coats I wanted. I'm sure my inexperience played a large part in the less than perfect results I had with the initial coats too. Although it didn't dry with the gritty appearance that suggests that the finish has dried en-route, between the spray nozzle and the guitar, I suspect it was dry very shortly thereafter, before it had a chance to self-level completely. As a result, some "orange peel" was evident after the first couple of coats. With more practice, the addition of the distilled water and cooler, more humid weather on the second day of spraying, however, I was pretty happy with the appearance of the later coats straight off the gun.

I waited a couple of days to level sand and a few more days before attempting to polish out the finish. Without a buffing wheel at my disposal I use a random orbital sander and Surbuf polishing pads purchased from Lee Valley Tools in the U.S. The polishing compounds I used are made by Autoglym and are branded 03B Fine Abrasive and 02B Ultrafine Renovator. They replace the Meguiar's products I used previously which I found unsatisfactory for my purposes. After a week, the finish on this guitar is HARD, and it's a slow but satisfying process sanding through the grits then rubbing out to a high gloss with the polishing compounds. Perhaps as I hone my skills I'll think about building a buffing wheel, but I feel there's less chance of buffing through to the wood with my current method, which is certainly slower but much less prone to burn-through.

Having progressed this far, I'm increasingly confident that the KTM-SV is the safe, environmentally-friendly finish I've been looking for. Those who've used it for some time and have had instruments out in the real world for two or three years have reported no issues with it which strengthens my belief that this is the ultimate finish for the the health-conscious amateur luthier with limited resources and a less-than-ideal working environment. For an even more low-tech approach, I understand it can be brushed on which makes this product suitable for even the rawest of beginners.

I'll post glamour shots soon - minus the scantily-clad model - when the guitar is strung up and ready for delivery!

Cheers

Pete

OM Nearing Completion

2009-11-22T15:56:00.019+08:00

Click for a larger view

With its new owner due to visit in a couple of weeks, I've been spending a lot of time lately preparing this guitar for finish.

Here's a shot taken this afternoon after shooting a couple of seal coats of 2lb-cut de-waxed white shellac. Prior to spraying, I inflated a couple of party balloons inside the body of the guitar to seal off the soundhole and the soundport, preventing any contamination of the interior.

Given my limited experience with sprayed finishes, it's a case of "so far, so good". I arrived at what I think was the right combination of spray gun settings more by trial and error than anything else. Setting the correct air pressure at the compressor, then adjusting spray pattern, air flow and material flow at the gun took some patience but, as with anything unfamiliar, the secret lies in constant practice.

Without a dust-free environment to work in my finishes are never going to be flawless but, under the circumstances, I'm pretty happy with the results so far. My hope is that the top coats of KTM-SV are as easy to apply as the shellac seal coats were. I guess I'll find out over the next few days!

Cheers

Pete

The Cautious Approach

2009-08-04T18:51:00.032+08:00

The way I see it, pledging the guitars I'm currently constructing to keen players free of charge has a dual benefit. Not only is it a nice thing to be able to do for someone who might otherwise never own a handmade instrument, but I also get to have my guitars road tested under real-world conditions. With instructions to play the hell out of them and subject them to the rigours of everyday use, hopefully they'll take this treatment in their stride and I'll be more confident of approaching guitar building as a commercial enterprise, albeit in a limited way. Were I to keep the guitars for my own use, I'd really be none the wiser; they would see little use and, when they were played, I'd follow past practice and handle them with kid gloves. I'd rather not make the assumption that life for a guitar is always that easy! I have sold several instruments in the past, but I feel I did so in ignorance of the risks and the potential for conflict.

Having built around 15 electric and acoustic guitars over the past 20 years, I know that structurally they'll hold up just fine. The area in which I do need reassurance is with the finish I'm about to use for the first time. KTM-SV, a water-based urethane, is receiving great press from those who've tried it, but I'd like to see for myself how it stands up to use and abuse over, say, 12 to 18 months. I can extrapolate from there and make an assessment as to what the longer-term prognosis is likely to be. The manufacturer, Grafted Coatings, has this to say about KTM-SV:

KTM-SV Spar Varnish wood finish is a waterborne, oil-modified, self-crosslinking urethane system. It features high quality, low film yellowing, excellent chemical, mar and scuff resistance, and is specifically designed for finishing wood. Because of its inherent oil urethane characteristics, the user can expect excellent flow, leveling and penetration into porous wood surfaces. Applied by spray or brush, maintaining high solids in the coating allows for good film build and fewer coats to apply.

In my search for a safe, environmentally friendly finish material, I've found any number of products which sound good on paper, however, the reality is that the demands placed on a finish destined for an acoustic guitar are unique. Tops, backs and sides are in the region of 2mm to 3mm thick and expand and contract unhindered. Not only does the finish need to be wear and scuff resistant, but it must also be flexible enough to withstand these changes in dimension on a daily basis. Add to that the guitar-buying public's expectation that their prize instrument should have a mirror-like gloss and the list of candidates shrinks significantly!

Cheers

Pete

Fretboard Completed

2009-07-27T08:41:00.011+08:00

Here are some shots of the completed fingerboard which I've slotted, inlayed and bound.

The benefit of some years of experience is that I've come to recognise and accept my own limitations. A more ambitious inlay design would in all likelihood stretch my patience and there's every chance I'd put off completing the job. The other advantage of a simple inlay design is that it looks so darn good, at least to my eyes! Less is more as they say.

The edges of the fingerboard are bound with black and white veneers and a 1mm outer layer of koa. Once the fingerboard was bound, I ran it past an upturned spiral downcut router bit to form a rebate along the edge that will adjoin the neck shaft. Black and white purflings were then glued into this ledge.

Cheers

Pete

Radiusing the Fretboard

2009-07-05T18:52:00.024+08:00

Here are some shots of a jig I constructed which helps me put a 12" radius on the fretboard. I take no credit for this idea - I found it on the Luthier Supplies web site. As a luthier living in Australia, astronomical freight charges from the US and a dismal currency exchange rate mean that making my own copy is the only viable option. Don't worry, I'm used to it!

As the pictures show, the carriage to which the fretboard is attached slides in curved slots routed in either end of the jig. The fretboard is attached with double-sided tape. The carriage is moved incrementally along the slots, gradually increasing the degree to which the fretboard is tilted from the horizontal. After each such adjustment, the entire assembly is passed through a drum sander. The end result is a faceted fretboard whose radius is very close to the required 12".

After removing the fretboard from the jig, I'm ready to refine its curvature. I attach it with double-sided tape to the flattened face of a piece of rock maple and mount it in my vice. I use an aluminium sanding beam having a milled concave surface with a 12" radius and affix 120 grit sandpaper with - you guessed it - double-sided tape. A few strokes along the length of the fretboard and the job is complete - at least for now.

Cheers

Pete

Carving the Heel

2009-06-21T15:45:00.011+08:00

Pictured here is the result of a couple of hours spent shaping the heel. This is as far as I'll proceed for the time being; I'll carve the neck and fine tune the shape of the heel after the fretboard has been glued to the neck shaft. I've chosen to rough carve the heel prior to attaching the radiused fretboard as it's easier to secure the neck in a vice or clamp it "heel up" to a benchtop without it.

I use a template to pencil in the shape of the heel where it will meet the sides and a second template to mark the outline of the heel cap. Although the intersection of the heel and the sides is critical to the accurate alignment of the neck with the centreline of the body and is crucial in establishing the correct neck angle relative to the bridge, there's a large degree of latitude where the shape of the heel itself is concerned. It's an ideal opportunity to inject some creativity and there are some wonderful examples where luthiers have done just that. Personally, I prefer to keep it simple and a graceful set of curves and a slim, refined look are my primary goals.

I carry out the initial shaping using a variety of chisels, then move to rasps and files. As the heel approaches its final shape I switch to scrapers and sandpaper. Shadows cast on the heel while holding the neck up to a bright light help identify any remaining lumps and bumps. Although I'm aiming for symmetry, I'm not obsessive about it - I'm happy to rely on visual cues such as this to highlight any inconsistencies.

Cheers

Pete

An OM for Maurice

2009-06-15T19:15:00.018+08:00

As a music lover as well as a guitar builder, I can imagine no greater reward for my efforts than getting my instruments into the hands of great players. With that goal in mind, here's one of the instruments I'm working on which I look forward to sending to friend and musician Maurice McGovern in Melbourne.

Soundports like the one pictured are becoming commonplace on custom instruments and, having added one to an old guitar of my own, I can vouch for their effectiveness. US builder Matt Mustapick has this to say about soundports:

This concept came originally from the great classical maker Robert Ruck, who puts two small holes on each side of the guitar, very close to where the neck joins the body, rather than one larger hole. The main advantage of the soundport is that it gives the player a "front row seat" to enjoy a strong direct signal from the soundbox. This feature takes nothing away from the forward projection of the instrument. From 20 feet away the guitar is just as loud. For anyone closer to the guitar, it adds a great deal of richness to the sound, owing to the dual sound source which creates a stereo field.

The combination of rosewood with koa trim is one of my favourites and I can't wait to see the effect when a finish is applied; the rosewood will darken considerably and the curly koa will really come alive. The small clamps I use when gluing kerfed linings came in handy for pre-gluing the purfling lines to the koa bindings prior to bending them in my Fox bender. I used Titebond 3 for this job and there was no sign of delamination which can happen with regular Titebond.

The purflings around the perimeter of the top and back are comprised of black-dyed maple and natural maple veneers with a 1mm mahogany centre piece. The five veneers were glued up as a sandwich using Titebond 3. I then cut the sandwich into strips on the bandsaw (a table saw with thin-kerf blade would be better) and ran them through my thickness sander prior to bending. On future guitars I'll substitute black fibre for the black maple; the maple gave way on the outside of some of the tighter bends. Luckily, I took the precaution of bending a few spares at the same time.

The overlay on the rear of the headstock strengthens the splice - not that it really needs it - and also obscures any glue line where the headstock joins the neck shaft. It's a much cleaner look as well as another excuse to use more of that beautiful koa!

Cheers

Pete

What's on the Workbench

2009-06-14T17:36:00.001+08:00

Never one to complete a project before moving onto the next one, I currently have a number of instruments at various stages of completion:

14-fret 000 - Australian Blackwood back and sides, Sitka Spruce top
14-fret 000 - Claro Walnut back and sides, Sitka Spruce top
14-fret OM - East Indian Rosewood back and sides, Engelmann Spruce top
12-fret 00 - Claro Walnut back and sides, Engelmann Spruce top
F5 mandolin - Maple back and sides, King William Pine top

My excuse? As a hobbyist luthier, my choice of finish materials is limited due to lack of access to a spray booth with an explosion-proof fan, etc. I've been down the nitrocellulose path before in more reckless times, but I've had time since then to contemplate the health and safety issues associated with use of that material. As a result, the unfinished instruments have banked up while I explore the alternatives best suited to my hobbyist status, more cautious approach and limited workspace.

I used Birchwood-Casey Tru-Oil successfully on several earlier instruments - it's very forgiving and can be brought to an attractive sheen - but, ideally, I'd like to find a finish I can spray safely and ticks all the boxes where ease of application, appearance, durability and repairability are concerned. A tall order perhaps, but I've finally bitten the bullet and ordered some of Grafted Coatings' KTM-SV, a water-based urethane which I've heard encouraging reports about. Luthiers Mercantile now stock it in addition to Grafted Coatings' KTM9, a water-based acrylic lacquer which promised much but, despite the best efforts of any number of talented builders over a number of years, has not delivered dependable results. Although it still has its advocates, I've read enough negative reports now that my own unopened tin of KTM9 will be thrown out in favour of the KTM-SV I'm currently waiting for. For an excellent discussion of KTM-SV, have a look here.

I hope to post a few pictures of works-in-progress from time to time, as well as share methods and jigs which have helped take the guesswork out of a particular process or have contributed to a more consistent outcome. And, who knows, perhaps this blog will chronicle the completion of my first F5!

Cheers

Pete