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Building 1st 12 string, second acoustic guitar. What if any modifications should I make to bracing for the top or back vis-a-vis a 6 string? If the braces should just be heavier, then knowing that noobs like me are prone to overbrace a guitar anyway, should I just brace it as I did my last and figure that'll be about right?

For what it's worth, I'm building an SJ-ish body, and have plans for an OM (my last guitar) that I'm schooling off of.

Jay

12 strings put considerably more force on a guitar top than 6. 12 string failures are common. I have seen examples where the force of the strings has driven the finger board extension through the top. This was on a Martin with a top patch that is often omitted by some builders. Martin uses 5/16" braces and a much larger bridge plate. Sides have mahogany braces rather than cloth supports. In David Young's classic "The Steel String Guitar: Construction & Repair" the 12 string plan shows an additional traverse brace extends through the x-braces at the top edge of the bridge plate and additional braces that extend the sound hole braces down to this new brace. The box and neck also need to be stronger without getting too heavy.

Irving Sloane's "Steel String Guitar Construction" just shows a larger bridge plate. (His braces are large even on the 6 string.)

I hope others will chime in as this is a more difficult design problem for which there is less published information

some where I have seen pictures of a double x braced guitar , a set of braces parrallell, to the standard x's , lower in the lower bout . I assumed it was for a 12 string since six strings dont need them ... Jody