Soundboard woods

[Fernando Esteves]

Hello!
I've a J45 I've built with Sitka/Limba that I've built on a course and am planning to try to steel build by my own, my idea is to do something different wood wise, to have a different tone.

I'm thinking Redwood or Red Cedar or other kind of cedar like Port Orford or Alaskan Yellow for the soundboard, to have little less attack and more harmonics.
Problems: I've a heavy hand, like I'm from heavy metal and hard rock, so I fear a softer soundboard doesn't work well...
Also, the description of these woods are always close to each other, I'm not sure what is best to think.

Do you guys think these woods could be roasted, too?

Thanks

[Alan Carruth]

In my experience, Redwood tends to be harder and denser than WRC, but otherwise very similar. I tend to use Redwood on steel strings for that reason.

I would not roast either one. The 'terrified' wood I've seen has a strong tendency to split, and Redwood and WRC both do that anyway.

The Young's modulus along the grain determines the bending stiffness at a given thickness, and stiffness, not strength, is the limiting factor in how thin and light you can make a guitar top. As a rule of thumb the long-grain Young's modulus for all softwoods tracks the density fairly closely, and does so in the same way for all the species I've tested. Something like 60% of the samples I've checked fall within 10% of the predicted value for Young's modulus based on density. That is, a Redwood top and a Red Spruce top of the same density are likely to have the same bending stiffness along the grain at a given thickness. There are outliers, of course, and there's no real substitute for measuring, but if you can't or don't the rule of thumb is reasonably safe, and beats just going by species or appearance.

[Fernando Esteves]

Thanks Alan!

Do you think Redwood would hold the pressure of a 12 strings?
Either in flat-top and archtop.

[Barry Daniels]

I will say that would be a recipe for disaster.

[Alan Carruth]

Redwood tends, in my experience, to be about as dense as the spruces in general, with similar long-grain characteristics. However, it is not as tough as spruce, with much more of a tendency to split. In this respect it's more like WRC, although redwood is harder (again, in my experience). To be reasonably sure that the bridge would not pull up you'd have to reduce the peeling stress along the back edge.

The way to do this is to make the bridge wider: longer along the line of string pull. This is what Martin did when they started having problems with bridges pulling up as they went to steel strings. A Martin 'belly' bridge doesn't have much more footprint area than a standard Classical bridge, but it holds up reasonably well under the higher tension because of the belly. I would not do this the way Gibson did, with the belly in front, since on Gibbys the pins end up very close to the back edge, reducing effective glue area there, and the short grain on either end of the saddle tends to break out: the worst of both worlds.

!2s also need to have a wide saddle so that the regular strings and octaves can be compensated differently. The top of the saddle has to be at least 3-16" wide, and 1/4" doesn't hurt. There will be two ridges. The peak of the one in front (toward the neck), will start out along the front edge of the bridge, and round back to the pins for the high E and B strings. At the B string the peak will be back a bit. The octave G needs the least compensation of them all, so the 'octave' ridge will start right at the front edge of the saddle, and angle back toward the bass. The regular strings get their own ridge behind that, at more of an angle. The ridges cut off sharply along the front, and round off at the back. The cross section of the saddle looks like a letter 'M'. I make both ridges the same height, and notch out whichever one I don't need for a particular string. If you try to do this with a single ridge it looks like a snake with bellyache. Ideally you should also do a compensated nut. This will reduce the need for saddle compensation.

I've been using double-compensated saddles on 12s for a long time, and they really help. The first time I did this with a compensated nut as well every note on every string was within three cents of 'perfect' intonation. The customer, who plays fingerstyle, no longer needed to stop in the middle of a session to re-tune so he could play up the neck. It was almost too smooth, but I figured I could always dial it back for a bit of 'crunch' by reducing the compensation a bit at either or both ends.

[Fernando Esteves]

Thanks, guys!

[Clay Schaeffer]

If you built an arch top you wouldn't have to worry about the "peel strength" of redwood.