Friday, October 9, 2015

Workshop Dreaming

I guess "rustic" wasn't in the forefront of my mind when I envisaged my dream workshop, although I've always considered that its setting should ideally bring me close to nature. The primitive outbuilding at the rear of our temporary home will function as my workshop - hopefully in the short term - and actually allows nature into the workshop! Needless to say, I'm prepared for my resolve and my adaptability to be tested in the months ahead.

Our cottage is simple but comfortable, but to state that the structure at the rear of the property that will function as my workshop is basic is to take the concept of understatement to new levels. I can deal with the uneven dirt floor, but it's the "air-conditioning" that is likely to provide the main challenge. I've taken the precaution of attaching a hygrometer to the wall behind the workbench; my guitars and I can seek refuge in the cottage whenever the relative humidity creeps outside of what I consider to be safe limits. In a controlled environment, I try to maintain a relative humidity of 45%, so alarm bells go off in my head when I see the gauge drop much below 40%, or begin to rise above 60%.

To take a pragmatic approach, I'm confident that if I pay close attention to the ambient temperature and relative humidity, the standard of my workmanship won't suffer, although my personal comfort may be less than optimal at times. Having said that, when I eventually have that dream workshop, you can bet I'll appreciate it!


Monday, October 5, 2015

Reality Check

The anticipation of moving east to the little village of Stanley in south-eastern Australia was difficult to deal with at times; for too long I've looked forward to devoting the majority of my working days to building guitars!

Reality has bitten though, and the prospect of building - or having built - a purpose-built workshop seems a little further away since the verdict of our appointed building inspector was delivered on the house Sandi and I inspected during our scouting trip a few months ago. The building inspector's findings were off-putting to say the least, but not entirely unexpected given that we're downsizing in a serious way, and looking at properties whose age and condition is reflected in their low price tag!

The little rental property we've selected as a temporary home is cosy enough, and is at least located in the village we've committed to settling into. However, storage and working space is in short supply and the prospect of commencing any new guitars seems like a distant dream. There is hope, however, when I reflect on the fact that the woodworking aspect of the guitars I have under construction is complete, and the process of applying finish to them is at least within my grasp - weather permitting. It's unseasonably warm and dry at present and with the relative humidity outside plummeting to the low twenties through the day, I'm wary of submitting guitar bodies to such conditions for any length of time. Hopefully, this spell of warm weather won't last and I can prepare to spray some finish top-coats soon.

Short-beaked echidna - a recent visitor to our garden.

Tuesday, May 19, 2015

The Call of the East

Stanley, known variously over the years as Snake Gully or Nine Mile Creek, is a small village located in a historic gold-mining area in Australia's south-east. It's primarily a nut and fruit growing area these days, but is home to a number of artists, artisans and - rumour has it - an odd assortment of eccentrics. I'm pleased to announce that, together with my partner Sandi, I'll soon be leaving the west behind and joining their ranks!

Approaching Stanley from the south
Along with this impending cross-country move, a significant downsizing will afford me the opportunity to build guitars in a more-or-less full-time capacity. What's more, with no pressing need to maximise output and profits, I can be totally self-indulgent and devote as much time as necessary to improving my guitar building skills, perhaps even diversifying a little into mandolin and ukelele construction. Most importantly, I'm looking forward to settling in a small community of like-minded people, and developing a more laid back approach to life in general, far from the hustle and bustle of the city. The stars are brighter too!


Sunday, March 29, 2015

Positioning the Bridge

There are several handy gauges and gadgets available that help the guitar builder determine the position of the bridge, but the method I've adopted works well enough that I haven't felt the need to try them out. To give credit where it's due, I believe I first saw the method I'm about to describe on Matt Mustapick's now defunct and sorely missed workshop blog.

On this particular Port Orford Cedar soundboard, the grain is incredibly fine and the centre join is extremely difficult to detect. I've lightly pencilled a line along the join to highlight it, then taped a sheet of graph paper to the soundboard with the centre grid line aligned with the pencil line. With the neck securely attached, I measure from the nut end of the fret board and mark the notional scale length on the graph paper - it's the longer of the three marks in the picture below.

I make a second mark a little under four millimetres further along the centreline to allow adequately for compensation, acknowledging that with wider saddles gaining favour among many builders these days - myself included - there's plenty of scope for fine-tuning of intonation once the guitar is strung up.

I measure the distance from the centre of  the saddle slot to the front of the bridge at its mid-point, then measure back from the compensated mark on the paper towards the nut by the same distance, placing a third mark on the graph paper to represent the front edge of the bridge. I extend this mark outwards in either direction.

The underside of the bridge has been sanded to conform to the dome of the soundboard, initally using a domed platform to which I've stuck some 120-grit sandpaper, and then, by way of fine tuning, by taping some 240-grit sandpaper to the soundboard itself then moving the bridge to and fro across the sandpaper until the white pen marks I covered the bridge underside with have been removed.

I insert a clamp through the soundhole, positioning a piece of MDF that conforms to the bridge plate outline inside the body and over the bridge plate as I do so. With the bridge clamped lightly in place over the graph paper, I wriggle it into position, using my third mark to align the bridge's front edge at its mid-point, and the grid lines that run perpendicular to the soundboard centreline to align the bridge's front corners. The clamp is tightened, and I drill through the first and sixth bridge pin holes so that the bridge can be accurately pinned in position when the time comes to permanently attach it to the soundboard. The MDF inside the body prevents chipping when the point of the drill bit exits the bridge plate.

Removing the bridge, I replace the graph paper with a thin, low-tack adhesive film known as frisket film. I give the film a light scuff with fine sandpaper so it's easier to mark. I pin the bridge into position through the first and sixth bridge pin holes, and lightly mark the bridge outline onto the frisket. I remove the bridge and, using a craft knife, carefully cut through the frisket around 3/16" inboard of the pencil line, being careful not to cut into the top wood. I can then peel off the frisket that sits outside the scored line. I've found that by leaving a generous margin between the edge of the remaining film and the actual bridge outline, it's much easier to level-sand and buff the finish in the area of the bridge perimeter, bearing in mind that the frisket film is removed only when the finish has been buffed and I'm ready to remove the remainder of the finish within the bridge outline prior to permanently gluing the bridge.

In the interests of a neatness, I'll leave around 1/16" of finish inboard of the bridge outline, and rout a ledge fractionally over 1/16" wide around the underside of the bridge perimeter to a depth equivalent to the target finish thickness. To do so, I clamp my laminate trimmer to a MDF platform that's been domed to replicate the curvature of my soundboard. To prepare the MDF, I laminated two 3mm layers of MDF in my go-bar deck using a 25' radius dish as a base, then drilled a hole in the centre large enough to accept my chosen router bit. As previously described, the underside of the bridge has been sanded to conform to the dome of the soundboard before I rout the ledge.

As always, I'm open to suggestions and I welcome any comments.


Sunday, March 15, 2015

Pop Goes the Rosewood!

I know it's unfashionable in some quarters to get too enthusiastic about East Indian Rosewood, but after applying a first coat of epoxy pore-fill to the back of this guitar, I feel justified in getting just a little bit excited. Let's hope it sounds as good as it looks!


Friday, February 13, 2015

Software for Luthiers: New Version of Luthier's Workbench Released

Luthier's Workbench is a software application built with the instrument builder and repairer in mind.

It's been some time since I released a new version, due mainly to the fact that recent changes have not been particularly significant. However, there have been enough of them now that it's high time I made the effort to release an update.

Click the image for a larger view.
Adding to the motivation for doing so is a recent support call that related to a user's inability to save changes to the application database. He had been able to add and edit records previously, but error messages suddenly began appearing, seemingly for no reason. Before I'd had time to investigate, the user saved me any effort and discovered for himself that the attributes of the folder in which the data file is stored had somehow been set to "read only" at some point.

He was able to resolve the problem himself without difficulty, but to avoid the problem altogether, I've made changes to the program logic in the new version so that the folder attributes are explicitly set to "read/write" every time the application is started.

You can see a summary of the changes incorporated in the new version HERE

For anyone who hasn't encountered this software before, here's a summary of its capabilities:

For the Builder
* Record woods, hardware and finish materials for your instruments.
* Record dimensions, weights, deflection measurements and resonant frequencies for any instrument part.
* Record standard model features as well as popular options such as soundports, bevels or fanned-frets.
* Assign prices to each model and build option offered to automate calculation of instrument prices.
* Enter finish schedules and notes to serve as a valuable reference for future builds.
* Use the Image Gallery feature to link images to individual instruments.
* Store address and contact details for all your customers and suppliers.

For the Repairer
* Build a price list for the repair services you offer as well as parts either sold directly or used in repair work.
* Automate the preparation of quotes by selecting from your list of repair services and parts.
* Print quotes, invoices, receipts, job sheets and build specifications.
* Keep track of quoted jobs, incomplete and completed work, as well as jobs requiring an invoice.
* Identify unpaid invoices.
* View customer build and repair job histories.
* Compare income and expenses and keep track of Sales Tax/GST/VAT.
* Filter income and expenses by a date or date range.

 You can download a free, fully-functional 30-day trial version HERE.


Friday, January 23, 2015

Progress - Slow, But Relentless

Despite my slow progress, I'm pretty happy with the way this one's shaping up and amazed - yet again - how completing the gluing of the bindings restores the resonance that's lost when the channels for the purfling and bindings are routed.


Monday, January 19, 2015

Binding and End Graft Preparation

I attach the black and white side purfling strips to the ebony bindings with Titebond 3, a glue that's much more resistant to heat and moisture than the regular Titebond I rely on for so many other guitar-building tasks. The clamps I use when gluing kerfed linings to the sides come in handy for this task too. If only I owned enough to prepare more than one binding strip at a time - tedious! Once the glue is dry, I scrape off any beads of glue and level areas where the edge of the purfling stands proud of the ebony bindings.

Ebony can be stubborn to bend and prone to breakage, particularly if there's run-out present in the binding strips; I always take the pessimistic approach and bend a few spares. In an effort to minimise breakages, I spray them with Super-Soft veneer softener the day prior to bending, and heat the bending blanket to a higher temperature than I'd use for more compliant woods. Although a little spring-back isn't the end of the world where bindings are concerned, I run them through two cycles of heating and cooling to help set the all-important waist bend. On this particular batch of 12 binding strips, I'm pleased to report that all 12 survived intact.

The use of ebony bindings might pose some difficulties in terns of bending, but it does at least provide some latitude when it comes to preparing close fitting joints. I do my utmost to achieve perfection, but usually miss the mark to a greater or lesser degree; fortunately, imperfections are easily disguised with ebony dust and a drop of thin CA glue.

A short length of binding to which I've glued and mitered a piece of purfling is a useful aid when it comes to fitting the end graft. I carefully trim the ends of the end graft using a disc sander, frequently using the binding fragment as a substitute for the actual bindings as a means of checking progress as I sneak up on the final length. Only when I'm completely happy with the fit do I glue and tape the end graft into place. I know many builders trim the graft and miter its corners after it's glued in place but, as much as I'd prefer to avoid the situation, I like having the option of discarding a poorly prepared graft before I've committed glue to it. With the end graft successfully sized and glued in place, I can remove the appropriate length of side purfling from the actual binding strips, then miter the purfling ends to achieve a tight fit where they butt up to the end graft corners.

The point at which the bindings meet at the tail of the instrument is most commonly dealt with by simply butting the ends of the bindings together, but I find I'm more likely to achieve an invisible joint by introducing a matching 45 degree bevel to the end of each piece - commonly known as a scarf joint. The scarf joint is cut in such a way that the end of the binding glued on second wedges tightly under the end of the first. I treat the purflings in the same way. At their full length, the purfling strips extend well past the end graft, so I leave them intact and the location of the scarf joint therefore ends up somewhere other than the half-way point. It's perhaps because the joints aren't where you would expect to find them that they seem much more difficult to detect.

In the interests of achieving a snug fit when it comes time to install the bindings, I find it's helpful to have filed or sanded a facet onto their inner corners. I do the same to the top outer corner of the binding so that the filament tape I use to secure the binding as it's glued isn't cut by the sharp outer edge when force is applied to the tape. To avoid an ugly gap, I'm careful not to round over the top outer binding edge where it will intersect with the fretboard edge. With this in mind, I round over the binding edge in this area with the neck temporarily attached.

On the guitar pictured, which has a florentine cutaway, the curvature of the plates - the back in particular - is such that the sections of binding destined for the cutaway must curve in two dimensions. To achieve a neat, gap-free fit here, I've taken inspiration from the Ervin Somogyi book and fabricated two lengths of binding - one for the top, and one for the back - that have the necessary compound curvature.

To prepare them, I held a piece of stiff card against the inner surface of the cutaway and ran a pencil around the perimeter of the top and back plates; the resulting pencil lines described the curvature I needed to introduce into my ebony strips prior to bending them to match the shape of the cutaway. To make things easier on subsequent guitars, I've prepared a piece of 6mm MDF whose opposing edges conform to these curves. With an ebony headplate attached to the MDF template, a flush-trim router bit gives me a clean edge that's guaranteed to conform to the floor of the binding channels without the need to apply force that would distort the strips and cause gaps between the binding and the adjacent purfling.

Despite the fact that I sprayed the the first pair of strips with Super-Soft and left them to dry overnight, my attempt at bending them to conform to the curvature of the cutaway failed; evidently there was some run-out in my ebony stock, and both strips broke before I'd managed to make much headway. Plan B involved preparing four curved strips - two for the top and two for the back - again using the template pictured. I glued purfling to the edge of one of each of the pairs then, with the help of my drum sander, sanded all of the strips to a thickness representing a fraction more than half the width of the binding channels.

At a thickness of just over 1 millimetre, they bent easily even without the use of Super-Soft, and I was able to laminate the bent pieces to form the two full-width binding sections required. The ebony I used was perfectly black, and the fact that the strips are comprised of two layers will be undetectable once a finish is applied.

Perhaps an overlooked component of binding preparation is the mental aspect. Along with many other (most?) guitar builders, I don't particularly enjoy the task of binding a guitar, and I delay each step until I feel I'm a state of mind conducive to producing a good result. Fabricating and fitting the bindings to the point of the cutaway, for example, requires great patience and precision, and I make sure I'm relaxed but alert before I tackle the job.

Please feel free to offer suggestions and comments - the learning never ceases!

Useful links:
Super-Soft 2
Kerfing Clamps