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I'm working on 2 L-OO's at the moment and ready to form and glue top braces. I'm using a sitka spruce top about 2.4 MM. The bracing pattern plan only shows the usual tapered ends and usual carved angled taper to the top braces. Would I be jeopardizing this top by scalloping any of these braces to lighten the top brace structure????
Any ideas here???
I'm using the 2008 C. Grellier plans

I think my previous OM's ...even though I went basically by the plans too....are heavy on the tops. I tend to maybe keep the tops a little too stiff with a SS and have only built/carved braces to plan specs and always afraid to possibly weaken the top strength by scalloping...

Kent

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Bracing is the #1 place a builder puts his personal choices into practice, and affects greatly "your tone".
Even if you decide to follow the plans exactly, you are making a choice.

Flex your bracing wood and get an idea of how stiff it is. Break some off-cuts, and see how it fails.
Unless you go nuts, it is pretty hard to under-brace a top, or over-carve. In the worst case, you can cut away and re-brace.

And I'm not joking: BE BRAVE!

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Kent,
I'm building one that is based on those plans right now. This is only my third guitar, so I'm not an expert, but I did end up scalloping the top braces. I didn't follow any scientific method, just kept whittling away as I tapped and flexed the top, trying to advance its musicality while developing my own feel for a balance between strength and responsiveness. I didn't have to remove a great deal of material to achieve noticeable differences. I think they were changes for the better, but only time will tell.

I would add that I think Dave's advice to be bold and brave is excellent. I feel pretty strongly that my first two guitars were significantly overbraced, so with this one I decided to push myself to experiment and explore new boundaries. How else am I to learn what works and what doesn't?

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George :-)

When bracing a top , think about the stresses involved. You can under brace a top . In the area of the bridge there is torque and compressive loads . This can cause excessive bellying and in the long term cause intonation issues as well. I like to keep the braces at this point pretty full . Below the bridge saddle slot and pins you are more under tensional stress than compressive or torque. Here you can be more generous in the scalloping but if you over scallop you will take away some headroom of the top . It is a balancing act.
If you are a fingerpicker you can be a bit ligher braced than a flat picker would be. I have seen many tops that were lightly braced that distort to the point of making the guitar unplayable . If making the top floppy was the key , we would be bracing paper by now .

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" we would be bracing paper by now " Ummmm double tops aren't too far off!

John, I think you know what I mean, most new builders I see overbuild their tops.

A study of L-00's will show how thin and tall the bracing was on good sounding ones. Tops, not so thin.

A general range of thickness, for nice stiff Sitka on an L-00 would be .115" top, and bracing 1/4" or even 7/32" thick, and triangular shaped up to 1/2" tall at the cross. Same for the tone bars, and you can do 1 or 2, and you can scallop them some.

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FYI

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Here is a 00 made by Grellier:

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Build log

That is a nice 00 top, and I see room for some mild scalloping on both the X and the tone bars.
That opinion is from looking at a picture, mind you.

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