Home Road Map Resources Lutherie Tools
A short weekend, and no chance to get into the shop during the week. Worked on soundboard bracing.
can just barely see it in this picture, but I drafted the outline of the braces
on the underside of the soundboard. I did this by cutting out the soundboard
from my sacrificial copy of the plans, and marking around the edges where the
braces met the edge or would meet the edge if extended. With a straightedge
along the line of the brace, I continued the line out to the edge of the extra
material. This gave enough of a line to orient the straightedge after the plan
was removed, to draw the actual brace within the outline. This sounds more
complicated than it was!
Having split the brace wood once, I split it again, perpendicular to the first split. The first split went in tangent to the growth rings of the tree, and it split fairly straight down the length of the board. This split will go along the "ray" lines, radially from the center of the tree out. If there is any twist in the grain, or if the billet was sawn at an angle to the vertical, it will show up in this split.
As you can see, the split diverged significantly from the sawn face of the billet. I'll now resaw the braces out of the billet using the split planes as references, and the lines of the fibers will run uninterrupted through the length of the braces, at least in the center third or so of the brace.
Here's the curl of the week. This came off one of the pieces that will become part of the X brace. Yes, it's really one curl. The plane is a fore plane.
Here two adjacent sides of the brace blank are smoothed and square to each other; this was done with the fore plane. I'll mark the height and width from these sides and plane (or in some cases, re-resaw) the rough sides down to that dimension.
To keep track of what I'm doing, I lay each brace blank onto the plan as it's dimensioned. Here they all are, with the exception of the bridge patch. The small brace below the soundhole is in the plan, but not in Cumpiano and Natelson. I think the X-brace is more "closed" left to right on this plan because of the overall width being less, and that leaves more of a gap between the x-brace intersection and the bottom of the soundhole.
Speaking of the bridge patch, here it is being glued down. It's just a thin piece of rosewood cut into a trapezoid shape closely following the lines of the X brace. The boxed materials come with a piece specifically for this, but in the future I'll cut it from the waste on the back, as long as I'm making small guitars anyway. I haven't measured it out, but it seems I can get both the bridge plate and the peghead veneer this way. The grain on the bridge patch runs left-to-right. The caul is 1/4" plywood: I'll use a thicker one in the future, as it will distribute the clamping pressure better. I don't anticipate any trouble from using the thinner caul here, but better safe than sorry.
Here is the clamping arrangement for the upper transverse graft, a thin piece of spruce that runs under the area above the sound hole. The grain runs right to left. The piece is a cutoff from the soundboard material, less than 1/8" thick. It's an inch wide, and reaches to within about 3/4" of the edge on both sides -- far enough away to miss interfering with the linings when the sides are attached. It's being glued here with a piece of 1-by stock cut to fit it as a caul. I've read a number of things about this piece, and there's some controversy about its use. But I'll put it there because I'm building this first guitar "vanilla" and both Cumpiano and Natelson and the plans have it there, and it's traditional. Here you see there's a board underneath the soundboard for the clamps to bear on. The board is used in clamping the bridge plate as well, though you can't see it in that photo. The board is used for these wide, flat braces because a bit of extra pressure is needed to make sure they meet the soundboard over their whole surface, and a little extra pressure is needed for that. Other braces, as you will see, are clamped without such protection because the pressure is lighter and the soft faces of the clamps prevent marring the soundboard face.
After the graft is glued down, it is shaped to a rounded profile.
After rounding, the ends are beveled down to the soundboard level.
Finally, a notch is cut into the center of the graft to allow clearance for the truss rod.
here's the result of this weekend's work. Next weekend is Easter and my folks
are visiting, so I'll get even less done! Actually, getting all the brace blanks
roughly dimensioned took most of the time this weekend.
Home Road Map Resources Lutherie Tools
Copyright © 2001 Stephen Miklos