Does cedar need different bracing than spruce

[fazool]

I understand the general concept of different bracing styles but I have a question:

Given a parfticular guitar does spruce and cedar tops warrant different bracing?

I found a particaulr guitar with a very cracked spruce top but with intact braces.

This guitar does not have binding or purfling and it has a removable neck. So a top replacement doesn't seem that daunting. Then when thinking about it I imagined replacing it with cedar instead of the original spruce.

And that would make it a one-of-a-kind.

KNowing cedar's characteritsics (strength, etc.) are so different from spruce I wonder if it needed different bracing?

[printer2]

From what I have picked up you may need to go a little thicker on the top as compared to spruce if you use the same size braces. Sounds like a fun little project.

[WaddyT]

Depends on the piece of Cedar, but the general rule is 10 to 20% thicker on Cedar. Remember, too, Cedar is much more crack prone than Spruce. Personally, I wouldn't put Cedar braces on a Cedar top for that reason. But, that's just me.

[dekutree64]

Either thicker plate or different bracing. But "thin plate" building is not just a matter of making the braces taller. You also have to worry about localized deformation behind the bridge... either a large bridge plate, or different south quadrant brace pattern that supports both sides of the bridge, unlike the usual 2 diagonal tone bar pattern. And it becomes even more important to have tall soundhole braces and some sort of bracing between the upper transverse brace and headblock.

For a top swap, I'd say just make it thicker and try to duplicate the old bracing. But it could cause trouble with the neck, since the fingerboard will be raised up by the thicker plate. Dovetail would need shims, bolt-on might need the headblock holes enlarged upward. Or you could route a shallow pocket in the top for the fingerboard extension to drop into.

[fazool]

Originally Posted by dekutree64

For a top swap, I'd say just make it thicker and try to duplicate the old bracing. But it could cause trouble with the neck, since the fingerboard will be raised up by the thicker plate.

So I am thinking the spruce is .120", so cedar might be made .145"

So that's only .025" thicker - I would bet I could plane .025" off the bottom of the bridge to get everything lined back up.

And I would then re-use the same braces all around.

hmmmmm might be a fun attempt at a project

[jeff crisp]

If your going to retop it I would think removing the neck would make the job a lot easier to do. I would also think making new braces would be a better option than trying to remove all the old ones and then removing all the old glue back to fresh wood, further reducing the original dimensions of the braces in the process. If that was what you were planning on doing?

[fazool]

Yes, its got a bolt-on neck so that part will be easy. I was hoping to steam the old braces off and re-use them but maybe I should make new ones.

[printer2]

If the braces are hefty enough like most production guitars shaving off a couple of thou should be no problem if you can get them off cleanly.