The Black and Red Guitar

I've been working on this East Indian Rosewood/Sitka Spruce OM at more or less the same pace as I have the Claro Walnut/Redwood guitar featured in recent posts, but progress has fallen behind a little in recent weeks as I've focussed my attention on preparing the Walnut/Redwood guitar for finishing.

While I wait patiently for a trio of fine days suitable for spraying, it's a good opportunity to catch up a little where this black and red OM is concerned. The purfling has been in place for a week or two, and with the end wedge now installed, I've begun the process of gluing the ebony bindings in place. It's not a task I particularly look forward to, which hints at the fact that I'm yet to feel I've attained any level of mastery over this particular aspect of guitar construction.

It will certainly be intriguing to assess the two guitars' responsiveness and tonal characteristics individually, but I'll be especially interested to make comparisons between them. Shaping of the soundboard braces on both guitars was completed at around the same time, the end result being what I perceived to be similarly responsive tops once I'd concluded the cycle of brace shaving, tapping and flexing. If popular wisdom proves to be well founded, the wood species used in these guitars will have a significant influence on the sound I'm ultimately able to coax out of them, and they'll show themselves to be very different from one another, tonally speaking. On the other hand, my assessment could lend weight to the theory that the sound of an instrument reflects the builder's individual style and methods as much as it does the materials used in its construction, in which case their tonal differences might be more difficult to detect. Whatever the result, and for the first time ever, I can confidently predict that I'll be able to share sound files and/or videos with you here on this blog. Eventually, that is!

Cheers
Pete

Spray Day Delay

With epoxy pore filling of the back, sides, neck and rosette of this guitar completed, it’s a case now of waiting for a string of fine days and a concurrent break in my regular daily work commitments. Without an enclosed spray booth, I need three consecutive days of good weather to complete my spraying schedule, with a day off work an unfortunate additional requirement.

In readiness for spraying, I've calculated the bridge position and masked the top in the area of the bridge and fretboard extension with a thin, low-tack adhesive film known as frisket film. The edges of the frisket film in the area of the bridge are around 3/16" inside the bridge outline. I've found that by leaving such a margin, it's much easier to level sand and buff the finish in the vicinity of the bridge perimeter. The frisket film is removed only after the body is buffed and I'm preparing to glue the bridge.

After two brushed coats of Ilva TF23 sealer, I'll spray a maximum of five coats of Grafted Coatings’ KTM-SV per day, for a final result of 15 coats of KTM-SV on back, sides and neck, with 10 coats on the soundboard. After level sanding and buffing, I’ll end up with a thin, flexible finish that has minimal impact on the responsiveness of the soundboard while still providing an adequate level of protection.

More soon - good weather permitting!

Cheers

Pete

Delivery Day

What a great day it turned out to be. Tiani visited this afternoon and, after a nervous start, treated us to several songs, accompanied - of course - on her new guitar. I could have listened to her beautiful voice for hours.

Although Tiani is very appreciative and feels fortunate to be the recipient of this guitar, I can't help feeling that I'm the real winner.

Cheers
Pete

The Fingerstyle Guitar - Epoxy Pore Fill

While it's perhaps not in the same league as the Claro Walnut used on the guitar I've recently finished, applying the first coat of epoxy pore fill to the instrument pictured reminds me that each piece of wood has its very own character and unique appeal. Once again, walnut has cast its spell over me and I'm very pleased with the way this guitar is shaping up.

It's an unfamiliar feeling to be pore-filling an instrument so soon after completing the previous one. Typically, many months pass after finishing an instrument before I'm ready to repeat the process, but as I work my way through this current batch of three guitars, I'm no sooner finished with one part of the process than I'm ready to repeat it on the next guitar.

With the necessity of a day job to distract me, the prospect of spraying the finish coats presents something of a problem: to apply the necessary number of coats to the back, sides and neck, I need to devote three consecutive days to the task if I'm to limit the number of coats per day to five. As I'm employed on a contract basis and paid by the hour, the bad news is that I'll need to sacrifice a day's pay if I'm to successfully apply a sprayed finish to the guitar - all the more reason to begin selling my instruments!

Cheers
Pete

The Fingerstyle Guitar - I Can Smell the Finish Line!

After a few days' break from guitar building during which I've enjoyed noodling on Tiani's Claro Walnut /Sitka Spruce 000, it's time to get back to the workbench.

I delude myself with the notion that this Claro Walnut/Redwood OM is essentially complete, ignoring the fact - because it pleases me to - that the lengthy process of filling, finishing and buffing lies ahead of me. After a solid day's work installing the remainder of the purfling and bindings, a few hours' final sanding sees me ready to apply epoxy pore fill to the back, sides and neck. The walnut back and sides are not as spectacular as those of the 000 I've just finished, but there's enough subtle flame evident that I'm confident the final package will look pretty slick - the Macassar Ebony and Zebrano components almost guarantee it.

Cheers

Pete 

Claro Walnut/Sitka Spruce 000 - More Photos

Some final photographs before I deliver this guitar to its new owner.

Cheers
Pete

Claro Walnut/Sitka Spruce 000

I was finally able to string up this guitar yesterday, and I look forward with some excitement to presenting it to Tiani, its new owner.

Tiani is the talented daughter of a family friend, and her youthful passion for music is truly refreshing. Although her musical inclinations have little in common with those of the players I imagine myself building for in the future, she's nevertheless a worthy recipient of this instrument on the strength of her originality and enthusiasm alone.

I began this guitar three or four years ago, and at some point over the course of its construction the decision was made to donate it to someone I felt could put it to better use than I could. There were some minor cosmetic blemishes that irked me, but more significantly, after the box was closed up and remedial work became impractical, I was concerned that the top was braced too heavily. As a result, I had serious doubts about its likely success from a tonal perspective and it took a back seat to other guitar projects for a couple of years. With that as a background, I was prepared to be less than impressed yesterday when I strung it up for the first time, and my initial assessment was indeed less than enthusiastic. However, after only a few hours, I was much less critical; in the absence of any other explanation, I suspect the strings simply needed to be left in peace for a short time to acclimatise to their new home: bent over saddle and nut and brought up to concert pitch. It's early days still, but I'm prepared to cautiously pronounce the guitar a success - I hope Tiani feels the same way!

I'll let the guitar settle further over the week ahead, make final adjustments to neck relief and action height, and hopefully hand the guitar over to Tiani soon afterwards.

Vital statistics:
Back and sides: Claro Walnut
Soundboard: Sitka Spruce
Neck: Tarzali Silkwood
Fretboard and bridge: ebony
Bindings: curly maple
Scale length: 24.9"
Finish: Grafted Coatings KTM-SV
Pickup: K & K Pure Mini

Cheers
Pete

KTM-SV - Sanding and Buffing

There are a multitude of guitar finish products available, and it's generally acknowledged that each of them have their advantages as well as their shortcomings. The dilemma for the guitar builder, then, is in deciding which particular compromise they can live with, and what product best suits their particular circumstances.

My current choice is Grafted Coatings' KTM-SV, a water-based, oil-modified urethane that a growing number of musical instrument makers are using with great success. I'm in the throes of completing the guitar pictured - my third using KTM-SV. Although I've been pleased with this product so far, if a little of its flexibility could be sacrificed for the sake of hardness, I'd be truly ecstatic. I'm keeping an eye out for the release of the manufacturer's new product - which I believe will be marketed as KTM-10 - in the hope that it makes up for what KTM-SV lacks in terms of hardness. Early reports sound very encouraging.

My technique with the spray gun tends to improve over the course of finishing a guitar, and by the time I've applied the last of the top coats, I've generally sorted myself and the gun out to the extent that the guitar's finish is level and reasonably smooth. After the finish has cured for a few days, the process of sanding through the grades of sandpaper can proceed. With the paper wrapped around a cork block, I begin sanding with 600 or 800 grit paper, depending on the quality of my last coat. I'm pretty cautious when sanding the edges of the body and the headstock; I skip the coarser grades and begin my sanding of those areas with 1200 grit paper, dispensing with the sanding block. I use soapy water as a lubricant throughout this process, and constantly check my progress by squeegeeing off the water and holding the body or neck up the the light to check for rogue sanding scratches.

Inevitably, I'll sand through the topmost finish coat to one or more of the underlying coats; witness lines are evidence of that, even after a thorough sanding with the finest of the papers. It's at this point, of course, that my attention turns to the buffing wheel, but I've learned that this finish needs a couple of weeks to harden enough that buffing will completely remove these witness lines. I've wasted a lot of time and effort and become quite frustrated when attempting to achieve a mirror-like gloss before the finish has had time to harden - it's just not going to happen! Not unexpectedly, it's also apparent that the finish shrinks ever so slightly over the first few weeks. On future guitars, I plan to delay sanding with 1500 and 2000 grit papers - if not all of them - until a couple of weeks has elapsed and I'm about to buff. Perhaps that's not so much of a consideration where the soundboard is concerned as ridges in the finish corresponding to grain lines seem to be accepted, given their inevitability when any of the more traditional nitrocellulose lacquers are used.

Links to Grafted Coatings' web site:
KTM-SV
KTM-10

To view previous posts dealing with KTM-SV, click here.

Cheers
Pete

The Fingerstyle Guitar - Latest Photos

I seem bogged down in the details at present, and it feels I'm making little headway. Nevertheless, here are some more progress shots.

Cheers
Pete

The Fingerstyle Guitar - Slow Progress

Despite the fact that I'm devoting most of my available spare time to completing a claro walnut and spruce instrument for a friend's daughter, there has at least been some movement with this redwood and claro walnut guitar lately. I'm content to proceed patiently, and I'm currently gluing purflings and bindings one piece at a time, through the week after I arrive home from work.

Acknowledging that the tuners and bridge are yet to be attached, the guitar is very light and, knowing how much I strived to brace the soundboard as lightly as I dared, I have great hopes that I'll achieve my goal of producing a very responsive instrument well suited to a fingerstyle player.

Cheers
Pete

Mitre Madness!

With the aid of lutherie's most underappreciated item of machinery, the disk sander, I've been preparing binding mitres and have almost finished these fingerboards and headstocks. 

Should I ever find myself building guitars for profit, bound fretboards and headstocks will definitely be an optional extra, priced accordingly. The rewards are great, but there's a lot of additional work involved.

Cheers
Pete

Claro Walnut - Not So Subtle!

With the luxury a few days off over the Christmas/New Year period, I'm proceeding steadily with the pore-filling process while I wait for delivery of the KTM-SV top-coat material. I'm perpetually amazed at the figure in this guitar's Claro Walnut back and sides, hence the repeated attempt at a photograph that will do this wood justice. Thanks Allied Lutherie!

Cheers
Pete

Pore Filling With Epoxy

After installing purflings and bindings, it's very rewarding to scrape them level, carefully round over the edges, then sand the top, back and sides in readiness for the first steps in the finishing process. It feels like the end of a journey while at the same time signifying the beginning of another equally challenging one.

With final sanding on this guitar complete, I've taken the first steps towards pore-filling the back and sides with epoxy, a process that finally reveals the true beauty of the wood. As a hobby builder, many months have inevitably elapsed before I get to this stage, but the rewards make the effort and the wait worthwhile. Along with stringing a completed guitar up for the first time, seeing the figure and colour of the wood magically appear as the first coat of epoxy is applied is surely one of the highlights of the building process.

On a cautionary note, a problem with some epoxies is that of amine blush, a waxy residue that forms as the epoxy cures that can interfere with adhesion and curing of subsequent top coats. From what I've read on the topic, spending a little more on a good quality epoxy is worth considering as they're less likely to be susceptible to blushing. Whichever product you choose, once the epoxy has fully cured a thorough rub down with a damp cloth - or, better still, one dampened with a 50/50 mixture of water and denatured alcohol - is a simple precaution that eliminates potential problems. There's wisdom too in avoiding the application of epoxy when the ambient temperature is falling and relative humidity is therefore likely to be rising - conditions said to exacerbate blushing.

Hats off to Todd Stock for putting together these very informative tutorials:
Epoxy Pore Filling Part 1: Application of First Coat & Sealing a Rosette
Epoxy Pore Filling Part 2: Prep & Application of Second Coat
Epoxy Pore Filling Part 3: Prep & Application of Third Coat and Prep for Finishing

Cheers
Pete

The Secret's Out!

A friend contacted me yesterday seeking advice about a suitable guitar upgrade for her daughter. As I've secretly had plans all along to make a gift to her of one of the guitars I currently have under construction, it seemed like a good time to reveal my intentions. As a result, I've decided to prioritise the completion of this guitar with a view to presenting it to her as soon as I can.

As luck would have it, I finalised the construction stage only a week ago - the task of finishing therefore begins in earnest. The first step is to fill the pores with epoxy after which two coats of Ilva TF23 sealer will be applied immediately prior to the first of the KTM-SV top coats.

I'll document the process here for the recipient's benefit and in the hope that it's of some interest to others as well.

Cheers

Pete

Guitar Necks: A Recent Improvement

I had time to daydream about guitar building over the last few months even if I didn't have opportunities to make progress in any practical sense. Among other things, my ruminations concerned construction of the neck in terms of how I might improve the design and produce more consistent results. Finally, with the university year over, I'm in a position to turn those thoughts into actions. 

In keeping with my usual method, two knock-down bolts extend through the headblock into threaded plugs embedded in the neck tenon. Although this is a popular and proven design, I've come to realise that there's an inherent weakness: if the bolts are overtightened through the soundhole by an inquisitive or over-zealous owner for some unknown reason, there's a chance that the force they exert on the plugs could eventually split the neck at the extremity of the tenon. However remote this possibility might be, it seems prudent to provide some reinforcement. With that in mind, I've modified my routing jig so that the tenon it produces is narrower than it once was, the idea being that I can build it back up to the desired width of 20mm by gluing a 2mm layer of wood to either side of the tenon as shown in the picture below. Crucially, the grain direction of these outer layers is at right angles to that of the neck shaft which provides good protection against splitting.

I'd like to achnowledge the luthier who came up with this idea; if I could only remember who they are I'd certainly do so!

I'll report on further improvements to my neck construction methods in an upcoming post.

Cheers
Pete

What's on the Bench?

Having swapped plane and chisel for scalpel and scissors, here's a picture of a recent project!

A Cane Toad gives his life for science.

I may have left it a little late in life to go "back to school", but the move has at least provided me with a new and exciting challenge as well as a much-needed sense of direction. Having said that, I'm already looking forward to a break at the end of the year and the opportunity to resume my regular woodworking pursuits.

I'll be back!

Cheers
Pete

Preparing Bindings and Purflings

When it came to preparing purflings for two of the guitars I'm currently building, the first step was to laminate veneer sheets into a black/white/mahogany/white/black sandwich. Rather than the black-dyed maple I used as the outer veneers when preparing an earlier batch of strips, I substituted black fibre sheet (sometimes called fish paper) this time to minimise the risk of deformation or splitting when the strips are bent to fit the purfling channels; the last time around, some of the black maple veneers collapsed slightly in the area of the waist and had to be discarded.

The brayer pictured above is a tool commonly used by printmakers - I sourced mine from a local art supplies store. It's the ideal tool to quickly and evenly spread glue when laying up the veneer sandwich. Titebond III is a glue well suited to this task; it's relatively heat and moisture resistant and the layers of veneer are less inclined to de-laminate when the strips are moistened and bent to shape.

With a small circular saw mounted under my table-saw bench and equipped with one of Stewart-MacDonald's fret slotting blades, I switched the saw on and raised it slowly, cutting through a masonite sheet I'd clamped over the table until the blade was fractionally higher than the thickness of the veneer sandwich, at which point I locked the saw's adjusting lever. Feeding the veneer sandwich through this very fine blade minimised wastage and resulted in an extremely clean cut. I was quickly able to produce enough purfling strips for two guitars, with a couple of strips left over as spares in case of breakage or buckling.

Preparing purflings for the rosewood guitar was an even simpler exercise; they're a simple combination of one black and one red veneer strip - thin enough that strips could be cut from the veneer sheet using a steel rule and a craft knife and pliable enough that pre-bending the strips is unnecessary.

Where the bindings are concerned, I chose to glue contrasting veneers to the edges of the binding strips - again using Titebond III - prior to bending them. Ebony bindings can be a pain to bend so I took the precaution of spraying them lightly with SuperSoft 2 veneer softener the day before I bent them - the softener plasticises the wood strips somewhat, reducing the chance of breakage. Taking care to arrange them into matched pairs, I taped the strips together, misted them with distilled water then wrapped the assembly of strips in brown paper and aluminium foil and bent them in my Fox bender. I began cranking down the press screw at the waist when the thermometer reached 240F and, when I'd bent the upper and lower bouts and applied full tension at the waist, let the heating blanket climb to 310F where I let it sit for a further 5 minutes. I switched the blanket off and removed the binding strips when the machine had cooled to room temperature.

Despite the fact that I'm currently working full time and distracted by those unpleasant but unavoidable weekend chores, I'm setting myself modest targets every week and making steady progress. Installing these purflings and bindings on the three guitar bodies is my next task.

Cheers
Pete

Guitar-Shaped Objects

With these guitar bodies assembled at last, I'm better able to imagine what the completed instruments might look like. It's very satisfying to have reached this stage, but I know there's a lot of work remaining.

Sitka Spruce/Claro Walnut; Sitka Spruce/East Indian Rosewood; Redwood/Claro Walnut

Having laminated the veneers from which I'll slice the purflings, my next job is to prepare purfling and binding strips, then rout out the ledges on the bodies to accommodate them. With the right jigs and tools this shouldn't be a particularly challenging job, but as a "hobby builder", the interval between guitars is significant; I'm not usually able to perform this task frequently enough that I ever feel entirely at ease with the process. With three instruments in the pipeline though, I should be feeling more confident by the time I carry out this step on the last of the current crop.

Cheers
Pete

Soundports

I've posted Matt Mustapick's observations on soundports before, but it seems an opportune time to do so again:

"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."

Prior to marking and cutting the side soundports, I took the precaution of gluing two thin layers of veneer to the inner surface of the sides as reinforcement.

Cross-grain veneers provide a measure of protection against cracks

In recognition of the veneers' primary purpose which is to strengthen the area around the ports, their grain runs perpendicular to that of the sides. Some builders argue that cross-grain veneers actually promote cracking by restricting the expansion and contraction of the sides that would otherwise occur. While I accept that such veneers do indeed limit the capacity of the sides to move with fluctuations in humidity, the distance between the linings in this area of the upper bout is small and any potential dimensional change is minimal. If it was a credible risk, we'd surely see cracks developing where the headblock and tailblock similarly restrict the sides' movement across the grain.

In addition to their practical role of protecting against cracks, the veneers also provide me with an opportunity to introduce a contrasting maple line around the walnut guitar's port and extend the rosewood guitar's black and red theme.

Dremel extension handpiece with mini circular saw blade fitted - before and after

A mini sanding drum in the Dremel handpiece takes me to the line

Final sanding required, but essentially, they're done

Very soon, I'll prepare myself mentally for the onerous job of installing purflings and bindings - a task that never seems to get any easier or less stressful!

A recent guitar, with soundport

Useful links:
The Shrinkulator is an online tool that calculates dimensional change in wood with variations in moisture content or relative humidity.



Cheers
Pete

Back at the Bench - Headstocks

Hopefully, this post marks a transition to business as usual after the disruptive and sometimes stressful process of moving house. As if that wasn't enough of a distraction, our newly acquired house and garden required a time-consuming facelift, but with much of that work now behind us, I can at last devote some guilt-free time to my hobbies.

Macassar ebony headplate

To ease myself back into normality, I've spent a little time working on the headstocks of the two guitars I'm currently building. Using a masonite template as a guide, I've band-sawn the headstocks to within a couple of millimetres of their final shape then accurately affixed the template to the headstock face using the indispensable and ever-present double-sided tape; a few taps from a soft-faced hammer ensures that the template is firmly attached to the headstock's face. The laminate trimmer I use to complete this job is adjusted so that a bearing on the shaft of the router bit rides along the edges of the template. Using this arrangement, it's then a relatively straightforward task to reduce the headstock to its final shape.

I've learned the hard way that when using this method consideration needs to be given to grain direction and the trimmer's direction of travel if damage to the headstock is to be avoided. Trimming the extremities of the headstock's end where they transition into its long edges demands special attention. On the upper corner of the headstock corresponding to the bass side of the neck, I guide the trimmer in a clockwise direction, effectively "climb-cutting" as the bit begins trimming the headstock's end adjacent to that corner; on the opposite upper corner of the headstock corresponding to the treble side of the neck, I guide the trimmer in an anti-clockwise direction. As an added precaution, I trim the end of the headstock before I trim its sides so that any minor chipping will be removed when the long edges are trimmed as a final step. Needless to say, different headstock shapes will require their own unique approach.

Observing the same precautions described above, I've also routed out the ledge that accommodates the headstocks' purflings and bindings, this time using a spiral-downcut router bit and the trimmer's adjustable guide. The rebate on one of the headstocks is pictured below, with the final result on the other shown for comparison. Hopefully, I'll have both of the headstocks completed before the weekend is over.

Laminate trimmer, with bearing guide fitted

Binding rebate prepared

Bound and ready for clean-up

I mentioned in my previous post that my plan was to construct a purpose-built workshop at the rear of the house. It's still an attractive proposition, but after much thought, I decided that at this point in time I'm unwilling to sacrifice what could easily be another twelve months of my life to such a major project - spare time is in short supply as it is. Another significant factor in my shelving of those plans is that once we'd found homes for the assortment of bits and pieces we all seem compelled to accumulate, a generous amount of usable space remained in the double garage at the front of the house. Importantly, with an abundance of fluorescent ceiling lights in the garage, lighting is more than adequate for my purposes. If there's a downside to my use of the garage for guitar building, it's that my partner may find her car coated in wood dust from time to time - I'm sure she'll understand!

Cheers

Pete