Fretboard Binding

Gluing the purfling to the binding before it's attached to the fretboard edge seemed to be the most logical approach when I began binding my fretboards, but I found it a challenge to accurately align the lower edge of the purfling with the underside of the board, no matter how careful I was when gluing and clamping it in place.

I managed to achieve acceptable results on the first couple of bound fretboards, but was uncomfortable with the process and felt there must be a better way. After dwelling on the problem off and on for a while, it occurred to me that I could just glue the binding on first - sans purfling - without fussing too much about aligning its lower edge exactly.

To solve the problem, I've knocked together what could best be described as a mini router table. With my laminate trimmer clamped in position from below, and a makeshift fence in place, I make some test cuts on scrap, adjusting the trimmer so that the rebate cut by the router bit will be the exact depth of the purfling strip. The width of the rebate isn't quite as critical, as long as it's less than or equal to the width of the purfling - any overhang can be trimmed off later.

Having set up the trimmer and fence, it's a simple matter of running the bound fretboard along the fence to accurately form the rebate for the purfling. The curved sections at the soundhole end of the board deserve some special treatment, but they're easily addressed using a similar approach.

All that remains is to glue the purfling strips into the rebate, with help from the same clamps used to glue kerfed linings strips in place. The purfling at the soundhole end of the fretboard is mitred to achieve a neat look.

I'm sure there are other equally effective methods, but this one works for me!

Cheers
Pete

Fingerboard Inlay

I think it's a commonly held view that for the majority of players, traditional fretboard markers provide little practical benefit (the markers on the fretboard edge are a different story), but I can't quite bring myself to leave the fingerboard totally devoid of decoration. Having said that, my ambitions where inlays are concerned are modest indeed, and while there's no denying the skill and sheer artistry displayed by the likes of Larry Robinson, Grit Laskin and Jimmi Wingert, I have no desire to emulate them - even if I thought I had the ability and temperament to do so.

The abalone and pearl inlay I've come to regard as my own was originally inspired by the decorative elements found on Bob Benedetto's arch-top guitars, but has evolved over time to the extent that my conscience is now clear - I no longer view it as imitation. I'm not adept at distilling design ideas down to abstract representations - I'd fail miserably at logo design, for instance - so whatever I dream up tends to be fairly representational. Where my fretboard inlay is concerned, I've stretched those personal limitations ever so slightly, but it's still blindingly obvious that the inlay represents a single flower flanked by two leaves.

I draw the shapes freehand, directly onto the pearl and abalone blanks, then cut the pieces out with a jeweler's saw. I don't feel the need to be terribly careful as I cut, knowing that the shapes of the individual pieces lend themselves to clean-up and refinement on my spindle sander. I'm quite happy for the exact shape to vary from guitar to guitar; given that I strive for accuracy and consistency where every other aspect of the guitar is concerned, it's nice to introduce some elements that have come into being by a more organic process.

My Dremel has its shortcomings and limitations, but it's an appropriate tool with which to route the inlay cavities. I need to keep the cavities free of wood dust as I proceed, and the solution is provided by an aquarium pump running alongside me on the bench. The outlet hoses from the pump are taped to one of the pillars on the Dremel base, and direct a constant stream of air onto the work. They disperse the ebony dust as soon as it's produced, which helps maintain a clear view of the lines I've previously scribed around the individual inlay pieces.

Using tiny spiral downcut router bits, I can cut accurately up to the lines, with a scalpel blade and my smallest chisel tidying up the corners that were too tight for the router bit to deal with. The inlay experts would have me believe that it's prudent to undercut the edges of the inlay cavities with a ball-end bit, but my inlay is so simple, and my results to date of a decent enough standard, that I haven't found it necessary to explore that option. If I've been careful enough, any gaps between the inlay and the walls of the routed cavity are insignificant. Those that are evident are easily hidden with matching wood dust and a drop or two of thin cyanoacrylate (CA) glue applied after the shell pieces have been glued in place. Of course, it helps that ebony is very forgiving in this regard!

Cheers
Pete

A Guitar-Shaped Box!

Hey, this is beginning to look like a guitar!

Cheers
Pete

Fitting the Back

Perhaps there's some aspect of successfully fitting the back that represents a significant milestone along the way to completing a guitar, or maybe it's just that I've repeated this part of the process enough times that I feel confident in the outcome and have come to enjoy the sensation and sound of the back braces clicking neatly into their pockets. Whatever the reason, it's a part of the build process I look forward to and derive great satisfaction from.

To reach this milestone - assuming that the dome of the back has already been sanded into the rims - I carefully align the back with the centres of the head and tail blocks, then mark the sides where the brace closest the the tail block will intersect them. I lay a steel rule across the guitar to join the corresponding marks, and pencil the line of the braces onto the top surface of the linings. 

As a precaution against chipping, I make a saw cut equal in depth to that of the brace end on the side of the pocket likely to be chipped by the clockwise rotation of the bit. I hope the right-hand photograph below shows this clearly.

With a spiral downcut bit mounted in the Dremel and carefully adjusted for depth, I rout the first pair of brace pockets, using the pencil lines as a guide. If the marks were placed accurately, the braces slip into place with just a hint of resistance. I check the fit of the back and widen the appropriate brace pocket to compensate for any misalignment. Once I'm happy with the fit and alignment, I can mark the next pair of brace pockets, confident that the alignment of the back will be more securely and accurately established as I proceed. When the four pairs of brace pockets have been prepared and the back fits perfectly, I can allow myself a moment of self-congratulation - before I remind myself that it's really only a minor triumph and that there's plenty of work ahead of me!

Cheers

Pete

The Modified OM

With the messy job of constructing a new bending form and outside mold finally out of the way, I've been able to make some progress on this guitar over the past week.

The walnut sides bent willingly, as they always do, and I was pleased to see that they conformed closely to the new mold, with the exception of some minor spring-back on one of the lower bouts. The spring-back was a useful reminder that it's advisable to subject the sides of any wood species to a couple of heating and cooling cycles before removing them from the bending form. I have to try hard to resist my innate impatience, and on this occasion I was a little premature in taking the second side out of the side bender, hopeful that such a compliant wood wouldn't require a second cycle. A quick touch-up on the electric bending iron soon had the side sitting obediently in the mold.

With the head block, tail block and kerfed linings glued to the sides, I'm better able to assess the new body shape. Needless to say, I'm greatly relieved that it matches my expectations, and that the time-consuming and incredibly dusty task of making yet another bending form and outside mold has been averted.

Noting the recent emergence of guitars referred to as "modified dreadnoughts", and lacking a more imaginative idea, it seems reasonable to dub my new guitar model the "modified OM"! 

Cheers

Pete

Kerfed Linings

I've fabricated kerfed lining strips from mahogany in the past, and while that's a popular and appropriate choice, on this guitar I was in the mood to use linings that closely match the colour of the spruce back braces. Spruce doesn't exactly grow on trees in my neck of the woods (puns intended), so I substituted Jelutong - a lightweight, light-coloured South East Asian hardwood species that serves this purpose well.

After bandsawing and thickness-sanding the strips, I set up a crude but effective jig on the bandsaw that helps me cut kerfs of a consistent spacing and depth. I leave a little more wood between the extremity of the cut and the opposite face of the lining than it seems is common with the off-the-shelf product, and the strips I prepare are a little more robust as a result. If there's any trade-off, it's that I feel the need to pre-bend the waist and upper bout portion of the linings on my bending iron prior to gluing them in place, more as an added precaution against breakage than out of any real necessity. 

A pet peeve, and the motivation for devoting a little time to preparing my own snap-resistant kerfed linings, is seeing an otherwise carefully crafted instrument whose linings are joined at some point, particularly when such joins are in plain view through the soundhole. Sacrilege!

Cheers
Pete

Headstock Binding Completed

Given the effort involved in binding a guitar headstock, I'm curious as to the upcharge a professional builder might reasonably apply, and whether a fee acceptable to the buyer could adequately compensate the builder!

Not only does my chosen headstock shape dictate that one of the sections of binding must conform to the tight curve at the extremity of the headstock, but mitering the individual binding pieces prior to gluing requires painstaking attention to detail. I know many builders cut these miters in-situ with a sharp chisel, but for better or worse, I choose to use my disc sander to do so prior to gluing them in place. As they're fitted dry in the first instance, I have the luxury of being able to discard any pieces whose miters don't meet my standards, with the need to start all over again acting as a strong incentive to get them right on the first attempt! With a light touch, and a patient approach that involves constantly checking for an exact fit, I'm able to produce tight fitting miters using this method.

Before I can think about mitres, however, I need to prepare the sections of ebony strip. The first step is to glue a black/natural purfling to one edge of the binding. I do so with the help of the clamps normally reserved for gluing kerfed linings, as the photo below shows. For the straight sections of binding, regular Titebond is adequate, but for those sections that will be bent into a curve - excluding the piece that fits the tightest curve and is treated differently - I like to use Titebond III, which is better able to withstand the heat involved in shaping the strips on my bending iron. Unless a piece of ebony is particularly reluctant to bend, I find they can usually be coaxed into shape without the use of water.

Gluing the black dyed and natural maple(?) purfling to the binding edge.

Maple veneer glued to what will become the inner face of the bindings.

Test fitting the first of the mitred corners, minus glue.

It goes without saying that accurately positioning the binding pieces as they're glued and taped into position, then tightly butting up the adjoining piece as it in turn is glued, contributes to an acceptable outcome. Call me strange, but when carrying out tasks like this that demand my close attention, I find that tidying up my work space before I begin unclutters my mind as well as my workbench - the Zen of guitar building in action perhaps!

One concession I make these days is to acknowledge that the tightly curved section can more easily be fabricated from two thin pieces of ebony rather than a single full width piece. As anyone who has attempted to bend ebony into a tight curve on a bending iron can attest, this makes life a lot easier. Once glued, scraped and sanded, it's almost impossible to detect that this section of binding has been laminated. To begin with, I run two pieces of ebony binding through the drum sander until they're half the desired binding width. The pieces can then be bent on the bending iron until they conform to the curve without the need to be forced into position. Once I'm happy with the fit, I laminate the two pieces of ebony, adding a layer of maple veneer to what will be the inner face as I do so.

Because this section of binding is fabricated from two layers of ebony, it's not possible to edge the piece with a strip of black and white purfling prior to bending as I did for the other pieces. Instead, I wait for the glue to dry, then clean up and glue one of the edges to a piece of black and white veneer sheet that has been prepared earlier. Once the glue has dried, the surplus veneer is trimmed from the inner and outer faces of the ebony strip, duplicating the look of the other binding pieces.

Completed headstock

Cheers

Pete