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Probably a silly question but....

Seems to me that side braces, if you orient the grain with the brace, place extra stress on the sides.

What I'm thinking is that since the side grain is oriented 90 degrees to the braces then the expandion/contraction of the side braces is greater. And how about different expansion/contraction rates of different woods? It seems to me that it would place constant stress on the sides.

Any thoughts on that? (besides the obvious that I'm just nuts?)

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Joe Beaver
Maker of Sawdust

It makes sense to me that expansion/contraction of the sides would stress he area of the brace although I have installed many. On my latest I have glued in cloth strips as a number of others have begun doing following the lead of Martin Guitars. I like the way it turned out and they go under the linings and cover the entire width of the side. All they are for is crack control. If I have a peice of wood that seems very stable and not prone to cracking I don't put them in at all.

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Tickle your guitar daily, and it'll tickle you back.

Im with John here, If im using a nice stable set of wood,and using it on one of my curvy models, i.e. not dreads, I forgo the braces all together.

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Lance@LuthiersForum.com

John,

I'm not familiar with the cloth linning. Sounds like you put it under the side brace and continue it under the kerfs to tie everything together? Same kind of cloth as the patch over the x-brace?

That would give a buffer between the different expansion/contraction rates. Brillant! What kind of glue do you use?

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Joe Beaver
Maker of Sawdust

In theory...yeah. In practice...the guitar's FULL of cross-grain joints that work out just fine. I want some kind of side reinforcement, if only to stop cracks from spreading once they start. For now, that's wood, because I like the look. I may try tape.

IMO side braces are like airbags. they won't prevent an acident but will prevent it from being faital. i supose that there is some added stess during climatic changes be it in small isolated areas. Cloth will do the same job but I don't like the look of cloth just a personal deal.
Structurally you don't need them providing that sides never take a impact, but I got to say that the guitar I put the rod though last weekk would be firewood if it had not been for side braces.MichaelP38767.7283796296

I used to use Wood side braces now cloth. If using wood they still have to go under the lining. I have one guitar that was nice stable wood and all, but when a client dropped it off a stage onto a cement floor, landing on the end the side cracked. But the crack only went from the Tailblock to the first brace and stopped there. If it didn't have a brac it would have cracked the whole way. ended up being an easy repair. As Michael said, they are like air bags. Hopefully never needed.

I'd like to know more about using cloth. Is it used by itself? No wood over it? What kind of cloth and glue?

Thanks,
Joe

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Joe Beaver
Maker of Sawdust

   I have used both cloth and wood for bracing . I use linen that I get at the sew shop. I use something with weight and strength and glue in with tite bond.
   

Joe, here is a link to a previous discussion we had about hem bias tape for side bracing.

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Don Atwood
Arlington, VA

Guys,

Thanks for the great info and the link. I'm going to have to do some studing and give it some thought. Sound like side bracing, of some kind, is the way to go.

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Joe Beaver
Maker of Sawdust

There's a lot more movement/stress on the 15-16" top and back than on a 3,4, or 5' side.

Ron

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OLD MAN formerly (and formally) known as:

Ron Wisdom

Somewhere in the middle of Arkansas......

There's a lot more movement/stress on the 15-16" top and back than on a 3,4, or 5' side.

Ron

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OLD MAN formerly (and formally) known as:

Ron Wisdom

Somewhere in the middle of Arkansas......

[QUOTE=old man] 3,4, or 5' side. Ron[/QUOTE]
Now that would be a guitar to get your arms around! Couldn't resist Ron.

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Don Atwood
Arlington, VA

You know what they say...everythings bigger in Arkansas... or is it better?

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Joe Beaver
Maker of Sawdust

Whoops!
And I said it twice.


Ron

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OLD MAN formerly (and formally) known as:

Ron Wisdom

Somewhere in the middle of Arkansas......

I just had a pretty nice sized crack in the waist of my current built. Pretty tight curve (Grand Auditorium).
The cracked stopped at my side braces. They did exactly what they were supposed to do.
I filled it in with some hide glue and clamped it up for about 30 minutes and now you can't even tell where it was.
-j.

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“If God dwells inside us like some people say, I sure hope He likes enchiladas, because that's what He's getting”
-jack handy

In theory wood side braces do probably put in a little stress. In practice, I'm sure it doesn't matter.

One advantage of wood braces is that the glue line is protected: with cloth you have to shellac it to keep air away from the glue, which will break it down over time. Wood braces are also stronger.

Bad point about wood: if they stop short of the liners there will be a stress riser right there, and if the side does crack, that's where it will do it. It's the hardest place to repair. Thus you _must_ inlet them into the liners, which takes a little extra time. The cloth tapes are thin enough that they don't materially interfere with the glue joint with the liners.

I've found the tapes to be very good at stopping side cracks from spreading.

Good Information and I thank all of you.

I've been building classical and never put side braces in. The thought of putting wood in there with the grain oriented 90 degrees scares me. I'm sure it will prevent an accident from becoming a disaster but I'm afraid that over time it could led to hairline cracks in the side as the braces expand and contract. On the other hand I've seen a lot of fine old guitars with no cracks.

Alan,

I hear what you are saying about extending the braces top to bottom. I'll definately do that.

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Joe Beaver
Maker of Sawdust

When I was using wood braces I thinned them down really thin at the lineings (1/16") and just ran the lineing over top, worked well as far as I know.