Official Luthiers Forum!

Hi all,

I am a complete novice, still at reading stage, and only just getting round to making my first work board for my first kit build classical. So forgive this naive question but I cannot seem to find the answer online or in any of the books I've read so far. When you are radiusing the workboard so that the back or top have the correct curvature when you glue on the bracing, do you radius the WHOLE shape or just the lower bout? All the stuff I'[ve looked at suggests only the lower bout (creating a circle based on the centre point of the bridge) but I cannot see how that would work. Surely the whole pattern needs to be concave?

Also, if anyone has any tips on creating a workboard (particularly the radiusing) with no power tools, I'd be very grateful to have them! Or do I just have to have a router?

Sorry if these questions are stupid. As a complete novice I feel a bit stupid so far - I guess things can only get better?!?!

Thanks,
Sean

No, it is the lower bout indeed, and usually continuing into the soundhole creating a teardrop shape. The upper transverse bar is flat.

When I did mine I simply used a chisel to remove some of the bulk and then leveled with 80 grit sandpaper. I had a nicely radiused brace salvaged from a factory guitar and used that to check the progress and find the high spots.

First you need to decide on the actual radius/depth of the solera as this will have a massive impact on your neck/bridge geometry, and probably on the sound as well.

Mine is about 3mm deep (15') and that is bulged enough to warrant a straight neck. If the fan braces do not seem to hold the doming well, I might add 1mm of tilt at the nut, in order to keep the fingerboard more or less the same thickness from 1 to 19. Alternatively (in case you get, or shoot for, lower doming) you can make a tapered fingerboard, say 6mm at the 1st and 4.5/5mm at the 19th. Both ways are fine.

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Build log

As Alex says, the dome is a teardrop shape in the lower bout. Roy Courtnall's book has a good description of that sort of doming, where the top is flat around the perimeter of the lower bout and in the upper bout. I built my first solera that way and have used it to build several Rodriguez and Reyes style guitars. (Of course, there is the method of creating the dome by having the lower bout perimeter fall away from the plane of the rest of the top - I assume this isn't where you are intending to go? John Bogdanovich' book provides an example, although there are easier ways to deal with the resulting taper on the sides.)

If you have a hand held orbital sander, slap a good heavy grit paper on there and you can get your doming done in short order. Work carefully, keep laying a straightedge across the dip and look at the dip at a number of angles, to make sure your profile is smooth, the maximum dip is placed where you want it and is the right depth, and the dip is tapering to nothing before reaching the outline of the guitar's shape (plantilla).

Or chisel (I'd prefer a fairly large radius gouge, myself). Many ways to get it done.

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Jim Kirby
kirby@udel.edu