Bracing wood

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Fernando Esteves
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Bracing wood

Post by Fernando Esteves »

Hi!
I'm just building my workshop and hope to build my first acoustic completely on my own soon.

I'm thinking, some spruce woods tend to sound a bit trebly and a bit harsh. Would the use of Cedar, Redwood or other softer wood could help warming a bit the tone?

The first one I'm planning would be Rosewood + Bearclaw.
Thanks!
Amateur luthier from Brazil.
I'm here to learn!!!
Alan Carruth
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Joined: Sun Jan 15, 2012 1:11 pm

Re: Bracing wood

Post by Alan Carruth »

'Spruce is spruce', especially when you're talking about bracing.

The sound really is in the top: you can't do much to improve a poor choice of top wood with 'better' bracing wood or a different brace layout, but it's distressingly easy to make a bad sounding guitar with a good top if you mess up on the bracing. This is more about the way the bracing is profiled, and the care with which it's assembled and glued, than the actual wood used for the braces.

Long grain stiffness (Young's modulus) tracks the density pretty closely in softwoods. A low density top or brace can be made as stiff as a higher density one simply by leaving it a bit thicker/taller. Usually, because of the 'cube law', the thicker low density wood will actually end up lighter at the same stiffness.

Braces, in any case, seldom make up more than about 25%-30% of the total weight of the top assembly: that's the point, they add stiffness without a lot of mass. On a Classical it's possible for all of the bracing together to weigh less than the bridge. Saving 5% of 30% of the top weight, 1.5% of the total, is hardly going to make or break the sound.

Spruce teds to be tougher than many other softwoods; less prone to splitting. WRC, redwood and Douglas fir, are all fairly splitty woods. Since braces do tend to get split from things like blows to the top, too much runout, or poor construction practice, it's wise to go with something tougher.

This is one of those areas where 'standard practice' makes a lot of sense.
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Fernando Esteves
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Re: Bracing wood

Post by Fernando Esteves »

Thanks for your input.
I just got from mail this week your DVD, hope I can use it well
Amateur luthier from Brazil.
I'm here to learn!!!
Gilbert Fredrickson
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Joined: Tue Feb 07, 2012 9:07 pm

Re: Bracing wood

Post by Gilbert Fredrickson »

Hand splitting brace wood was my least favorite part of the process.
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