PREPARING SOUNDBOARD GRAFTS AND REINFORCEMENTS

After a lot of speculation about the grain direction of these component, the soundboard doughnut in particular, I took the plunge and started making them. The bridge graft will be the only one running cross grain, the soundhole doughnut and the grafts under the fingerboard will both have the grain running parallel to those of the soundboard. Why? Well, it seem that most builders do it this way and so I sheepishly followed.

I started by drawing up the grafts of the soundboard cut-off, trying to position the components on the best, most vertically grained area, and at the same time trying to group them together leaving as much of off-cut intact, in case I needed to redo some of them later.

Once the grafts were drawn up, I cut them out with my dovetail saw and jointed the edges to final dimension. Both these task were done 'freehand' using the shootingboard as support. Once that was done I stuck the grafts on to the shootingboard with double sided sticky tape and planed them all to final a thickness of 2mm using my block plane with a 38º blade. This little plane is a true gem and now that I have the full set of blades to go with it, it is an incredibly versatile little setup.

The soundhole doughnut was cut using a drill press fly-cutter I bought a while back for this very purpose. I had to sharpen the blade and it was quite an ordeal doing this by hand, but I got a mirror finish on all three faces in the end. My intent was to use the angled part of the cutter to create a slightly beveled edge, partly because of aesthetics but also because I have read somewhere that the air in the body will be able to pump in and out more efficiently this way.

I soon realized that this was easier said than done. If I just turned the blade around to cut the inside bevel, the blade would also be cutting 'backwards'. To do inside bevel properly I would have to, either do some major surgery to the blade or have two blades, one for an inside bevel and one for an outside. But, as it was late and I was so close to finishing up I decided to do the unspeakable and have the inside bevel done with the blade running backwards - Yikes! However, Spruce is rather soft and it actually did kind of work, with a little bit tearout though.

All in all I found the fly-cutter a bit of an awful beast to deal with. It is a big and sturdy model made by General and as it only has a cutter on one side it through the whole drill press out of balance, cutting with a lot of vibration. As I said the cuts themselves were fine, but the whole thing was a very wobbly and rather unpleasant affair. I might use my StewMac circle cutter next time.

I finished the bridge graft by trimming the ends with a slight angle. The little triangular cut-off will be saved for later use as guides for trimming the underside of the fan braces where they cross over the bridge graft.

The fingerboard graft was left to be trimmed for final fitting later.

MEASURING AND DRAWING

CUTTING THE PIECES

JOINTING THE EDGES

PLANING TO THICKNESS

CUTTING THE SOUNDHOLE DOUGHNUT

CUTTING BRIDGE GRAFT CORNERS

THE FINISHED GRAFTS

PREPARING THE END BLOCK

Last night I made the end block. I used some off-cut the kind people of Rockler had given me for free. It wasn't perfectly quartersawn, actually it wasn't really quatersawn at all, more on the rift side of things but otherwise nice and clean.

I have been 'uhm'ing and 'ah'ing about which way to orient the grain on the end block for some time now. As with so many things in lutherie there seem to be many ways to approach the building process and there are equally many conflicting arguments as to why and why not. I ended up making the block with the grain running parallel to the grain of the sides. The theory behind it being, that the two components will have a similar movement when exposed changing humidity and temperature.

Anyway, I started by cleaning up one face and then proceeded to true one of the sides and one of the ends. Once they were true and square I cut the block to almost final dimension on the bandsaw and subsequently cleaned up the cuts on the shooting board. Finally the other face was planed so the block was left with a final thickness of 18mm.

To get the slight curve on the face that is going to be glued to the sides (to follow their curvature) I skewed the blade in the block plane with the lateral adjustment knob in the back. This way it was cutting deeper on the right side than the left, or rather, it was cutting a slightly skewed cut on the right side only. With careful planing this allowed me to visually see where and how much I was cutting off as the cross grain cut left a distinct mark on the wood where it started. Three stokes on each side of the middle did the trick, though I will probably have to make some slight adjustments to get a good fit, once I get to the assembly.

Last, I trimmed the corners of block by 'eye' just to create little more pleasing looking lighter block.

TRUING THE FIRST END

CUTTING TO DIMENSION

SETTING THE LATERAL BLADE ADJUSTMENT

TRIMMING THE CORNERS

FINISHED END BLOCK

FINISHED END BLOCK

PREPARING BACK BRACES

Recent evenings have been spent in the garage preparing the braces for the back. When I made the neck I kept the off-cuts for this purpose and I managed to have just enough scrap to complete the task. However, the off-cuts had some slight movement in them which made me somewhat nervous about their suitability. More so, it also made me wonder how well the neck is going hold up down the road. Time will tell.

First I cut the brace stock to proper length with my dovetail saw and miter box set-up. As one of the pieces was quite larger than the others, I ran that through the bandsaw first to get it close to the final dimension. Each brace was then attached to the bench with double side sticky tape and planed flat and straight to 6mm thickness.

Because I don't have a 'real' bench, I don't have the facilities to properly clamp down the braces as well as I would like to, and though I did get there in the end - sort off - it made these relatively thin pieces unnecessarily difficult to plane. As usual double sided sticky tape was called in to save the day (I thank the higher powers for double sided sticky tape!!) and with that, each brace was attached to the bench, butted up against a bench dog. Last they were jointed on the shooting board to a width of 15mm.

Once the brace blanks were done I scribed a 15' radius on each of them, using a template I made for this purpose and an ordinary scalpel, and planed the corresponding curve on the bottom with my block plane.

In Bogdanovich' book he suggests to profile the braces before gluing them onto the plates. This, he states, naturally cuts down on the amount of carving needed once they are on and thus limits the potential damage to the plates that might occur during the process. I don't know either way, but I it somehow appealed to me, and this was the way I did.

I approached the 'carving' the same way I did when I carved the heel for the neck - with bevels. The good thing about bevels is that you can quite easily monitor you progress by holding the work up to a light-source so it reveals each bevel very clearly as the light falls upon them. I planed two primary bevels on both sides of each brace and once they were as even and symmetrical as I could get them, I evened the profile out with secondary bevels.

In retrospect it proved to be more difficult to achieve a consistent and symmetrical outcome than I had anticipated. Again, it was hard to secure the work to the bench, in particularly when it came to do the second side, and double sided sticky tape only goes on and off a few times before it has to be replaced.

If I were to do this again I also think I would do the bevels in three stages instead of two: First, one primary bevel, then two secondary bevels and a third and pass smoothing it all out. But, so far so good.

NECK BLANK SCRAP

CUTTING BRACES TO LENGTH

THICKNESS PLANING THE BRACES

JOINTING THE BRACES

SCRIBING 15' RADIUS

PLANING 15' RADIUS BOTTOM

PLANING BEVELS

BEVELED BACK BRACE

FINISHED BRACES