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Time to turn a drawing into wood. My current project is for a shrunken Dreadnought, 18.5" long, 14.5" lower bout.

I've already chosen to try to not overbraced this one, and I'm using 3/16" wide bracing for the top, 1/2" high for the one lateral tone bar (think Larravee) and finger braces. What about the x-brace? I originally drew the 'x' as being 9/16" high in the center (tapered), and I'm wondering if I'd be better served by this one being a half-inch high, too. The red cedar top has been tap-tuned so that's a fixed parameter.

Anybody's SWAG advice will be joyfully received!

Thanks, folks.

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Peter Havriluk

In absence of any other takers…for a guitar that size, 1/2” brace heights will probably be fine, provided there’s enough stiffness in the top, bridge, and bridge plate. TBH 3/16 brace width skeeves me out a bit…

Thanks, Ed. Gonna find out. At least now I can start to build up the top and the back.

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Peter Havriluk

Thanks, Ed. Gonna find out. At least now I can start to build up the top and the back.

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Peter Havriluk

Sounds pretty dicey to me. Stiffness is proportional to width x height³, so 3/16" width is already quite a lot more flexible than 1/4" width. It also depends on the profile. Sharp triangular is 1/3 the stiffness of rectangular, so there's a large unknown factor there for us guessers. Triangular is popular for its higher stiffness to weight ratio, but you have to increase the height to make up for the loss of stiffness due to the profile. For a triangle and rectangle of equal width, the triangle needs to be 44% taller (cube root of 3) to have equal stiffness, and will be 72% the weight.

I’d stick with 9/16” for the X.

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It's not what you don't know that hurts you, it's what you do know that's wrong.