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I'm going to try some deflection testing on some brace wood. I'm wondering what sort of length and diameter people have been working with? I have some Sitka, Englemann, Lutz and fairly stiff Cedar to play with so I am looking forward to seeing the results. I know you don't have to be too scientific with your set up. A picture would be cool.

On the topic of brace wood, what do you guys find you get the best results with? If your not testing it, what do you look for. Grains per inch? Some of the Sitka I have has the tightest grain count on the sapwood. Wonder if that makes a difference? I'll also try some wider grain Sitka.

Thanks,
Danny

I pretty much exclusively brace with Adirondack Spruce. Best stiffness to dimension ratio, which allows the most radical scalloping. Nominal beginning stock for X brace is .25" x .5"
-C

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Freeborn Guitars
and home of BeauGuard©

Thanks for that Chas. I wish I had some Adirondack to throw in the test. When I asked about size I was referring to what a good dimension to use in a test.

Danny

I test lots of brace wood. I start with .75 X .32 stock for testing purposes, measure the deflecion across a 12" span and wiegh the brace stock on a gram scale. I grade my braces by their stiffness to wieght ratio not stiffness alone. I've concluded that you can't grade by spieces alone. I've had some great adirondack and some no so so hot adirondack, same with sitka, and european, engleman and lutz.
You can also learn to sort them just by tapping braces of equal dimensions, you'll get them sorted in right order but won't be able to attach any numbers to them, for ever that's worth.

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Jim Watts
http://jameswattsguitars.com

I do, I just sort it by mechanical properties regardless of species and use it accordingly. For example, stiffest braces for things like the upper transverse brace, and X brace and I use the most flexible for things like finger braces.

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Jim Watts
http://jameswattsguitars.com

The last one I did had a Lutz "X" and the rest was Sitka. I have come to one strong conclusion on this combination and that is that it makes for very good guitar like sounds and still has a very definite guitar shape.

Ok, that was pretty interesting. I used a dial on a magnetic stand on my table saw. Just a couple of 6" long 4x4's, 12 " apart and an 8lb weight. It seemed the best way to get most accurate values was to weight the ends down a bit. I tested Lutz, Englemann and Sitka, .625 x .3125. They were all pretty close but interestingly enough the higher the grain count the stiffer the wood. FWIW the Sitka had 4 growth rings and .023 deflection, Lutz, with 5 rings had .021 and Englemann, with 7 growth rings had .019 deflection. I milled a piece of cedar also but it was off the chart. I think I'll see if I have some tighter Sitka and see what the difference would be. Unfortunately no Adi or Euro to throw in. I thought I would share this because it was a new experience kind of interesting.

Have a good weekend.

Port Orford cedar is supposed to be very strong, and it smells nice too. Never tried deflection testing yet.

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"Preoccupation with an effect gives it power and enhances the error"
from "Your Owner's Manual" by Burt Hotchkiss.