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Anyone used this tonewood with success??If so, what changes did you make for bracing patterns ?? etc etc . thanks

Sitka tends to be denser than most (myself included) like for a classical top. You'd be better off with Engelmann, Lutz, Euro, or WRC. Having said that, I'm sure that if you really look around you can find a sitka top that is acceptably light. So if you're set on building a classical with it I'd suggest that go through a lot of sets and find the least dense top you can (while maintaining adequate stiffness).

I often do however like the combo of Engelmann top with sitka bracing.

If you measure the properties of a lot of top wood, you'll find that the stiffness along the grain correlates quite nicely with density, and all of the diferent species tend to fall on ther same line if you plot stiffness along the grain agaqinst density. What that means is that if you can find a piece of Sitka with a density that's in the same range as, say, good Euro spruce, it will make a good classical top, AND you can simply work it to the same thickness. FWIW, the Euro that I've tested seems to run around .36 for specific gravity, and Sitka tends to be closer to .44: about 20% denser.

A couple of other things to keep in mind:

There is _no_ correlation between grain count and any mechanical property of the wood.

Cross grain stiffness tends to correlate with grain angle: perfectly vertical grain is stiffer across the grain, and it falls off quickly as the grain angle changes, being lowest at 45 degrees.

Sitka may be a tad less stiff across the grain than other spruces, all else equal.

You _have_ to go by the individual piece, not the species! THere's so much overlap in properties of top woods that you can find wood of almost any species with the 'right' stiffness and density for a classical.

Thanks allan ,was looking for a way to correlate the stuff. Most of the sitka is pretty (green) ., will need to wait until it is bone dry,

Gilbert made some pretty good classical guitars with Sitka, but I think the other Spruces, Euro, Engelmann, Lutz are better for classicals. Maybe not better, but easier to get good results with.

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Waddy

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I have a flamenco guitar I did with a Sitka top. I took it down pretty thin - on the order of 2 mm. It has gotten good reviews from several flamenco players. It has very fast attack in the trebles.

I'm not sure I would do another one in Sitka, unless I were asked to. I'd rather leave the top a little thicker

Jim

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Jim Kirby
kirby@udel.edu

I built a Spanish guitar with Sitka once. It came out "ok" and got a lot better with time. I didn't change the bracing but I did thin the top considerably. I bet actually it would make a nice Flamenco guitar because it's rather punchy and brash. It doesn't have any of the warm qualities you might want for a Spanish guitar but it is quite percussive.