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A quick question that I hope will get some response. I am doing a quilted maple back and sides small jumbo and the mahogany kerf cut lining looks so great against the maple that I am thinking of doing the back bracing in Mahogany. It will look great through the sound hole I have never tried mahogany bracing so was wondering if any one here has and what their thought on the results are.

Fred

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Fred Tellier
http://www.fetellierguitars.com
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it's my default back bracing.

I've done a few but the last one collapsed before I had a chance to glue it on and I haven't used it since. I think it may have been poor grain selection on my part but the future use will be a wee bit heavier braces. Hog on Maple would look sweet!

Interesting idea and I bet it looks real nice. Do you split it?

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Steve Smith
"Music is what feelings sound like"

more weight than spruce but if you dont care then it would look nice.

Don't know why, but I have used mahogany back braces on all 5 guitars I've completed and the two I'm currently working on. I like it, and think you will too. Love quilted maple too, but haven't used it yet. Post some pictures when you get a chance.

I use it on my bouzouki builds. Works fine, and saves you a few $ by not using precious spruce. I use off cuts from the neck, so it's basically free brace wood for me. I have seen a guitar with a mahogany upper transverse brace, made by Foley in Ire. It sounded great.

Thanks guys, I realize it will physically work strength wise but I am more interested ion the sonic change on the back especially when using a live back which is my preference. Any thoughts on changes in back tap frequencies and stiffness.

Fred

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Fred Tellier
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Don't know but I doubt that anyone can actually hear the type of braces that have been glued to the Back of a Guitar. If they can then they probably can discern a 0.001 cent change in pitch.

i must admit i am surprised by these answers, as i wouldn't think mahogany would have nearly the strength:weight:stiffness ratios for good bracing....

Why not? It's frequently used for Necks and there's a few strings trying to pull that out of true.

I would have thought that back tap frequencies and stiffness are adjustable, be it spruce, hog or whatever.
I understand that with mahogany braces you have a higher weight for the same stiffness, so for the same stiffness of braced back plate, the weight would be higher, hence frequency would be lower.
Stiffer (slightly taller maybe) bracing would bring the stiffness and frequency up, but perhaps lower the amplitude of the response, and in turn this may lessen the contribution of the back live to the overall response of the guitar.
Having said that, I feel it may have a minimal effect.
FWIW, I used mahogany bracing for the top 2 braces on the back of my last build (for appearance only) but kept the lower 2 braces spruce as they are much less visible through the soundhole when the box is closed.
I wanted a live back, and felt the 2 upper braces have less impact on it's response.

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The name catgut is confusing. There are two explanations for the mix up.

Catgut is an abbreviation of the word cattle gut. Gut strings are made from sheep or goat intestines, in the past even from horse, mule or donkey intestines.

Otherwise it could be from the word kitgut or kitstring. Kit meant fiddle, not kitten.

Colin, I like your 1st 2 brace Mahogany idea, I never thought of that option.

Fred

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Fred Tellier
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I use all sorts of woods for back bracing, and good mahogany is fine. I think that a little extra mass in the back is usually not a problem, and may be a help. So long as you have some means of getting the bracing weight and stiffness 'right' for your build, the brace wood species should not matter too much.

Sp.Cedar is in the Hog.family.
I have some that is heavier(denser) then some Hogwood,

Been a great back brace wood for along while.

go for it!


mike

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Mike Collins

I'm with Mike on this one. Sp Cedar would give the look you want without adding weight. Very stiff and also has such a nice smell.

Brent

On average, and in the absence of tests on the specific board you have, that is all we can work on
-Honduras mahogany is harder but less stiff and more dense than spruce.
-Spanish cedar is less stiff than mahogany but less dense

So Spruce is THE high performance timber for bracing, but the others can be made to work if you allow for their lower stiffness

If you are doing a Trevor Gore style live back with scalloped lower bout brace and post build tuning, then any difference in stiffness would be accommodated during the tuning process as long as you don't do significant initial scalloping before testing

I'm with Filippo! HOG, Sp Cedar both make great back braces.

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Waddy

Photobucket Build Album Library

Sound Clips of most of my guitars

Spanish Cedar (Cedrela odorata) is not in the same genus as Mahogany (Swietana sp.); might be the same family, though.

In terms of Young's modulus along the grain and density, cedro is probably a better substitute for spruce than mahogany: it should make a lighter brace for a given stiffness. Of course, that assumes you want the back to be light and stiff. If that were the case, why do we use rosewoods and such for the backs anyway? Why not use spruce and do it right?

The fact is that the back has different job than the top, and, in most cases, does it better if it's a bit heavier, IMO. That's probably true in general even when you're looking for a 'reactive' back. Flamenco guitars are the only ones where the back is normally about the same weight as the top, although some low density mahogany can end up not much more massive than the top (maybe a third more or so). Are we always after a 'Flamenco' sound?

Hog? might be a bit dense for bracewood.


I do like MAhogANY though.

If it's just the color you're after, consider cedar...

Alan
They are both in the Meliaceae family!
that's the true Mahogany family.
good call sir!

Mike

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Mike Collins