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What is recomended for bracing a 12 string that is any different than a standard 6 string?

At some point I saw where an extra tone bar was added, but I am unclear about any other braces or extra stiffness to the braces? Is it better to have a slightly thicker top on a 12 string?

Also, I dont think I have seen it done, but can a slotted head be used for a 12 string?

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Reguards,

Ken H

Ken, Ovation has done a slot head 12 string for years. I even had one. Sorry for cussing (Ovation) on the forum!

I should have googled it first... I found oodles of slotted head 12 strings. Martin even did a 12 fret slotted head 12 string :)

Now, back to the question about bracing...

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Reguards,

Ken H

The problem with doing a slotted 12 string is finding quality tuners for it. The ones out there are crap.

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Guitars, guitars and more guitars.

I'm curious about this myself - I want to attempt a 12 string toward the latter half of the year - what are the major differences between building a 6-string and a 12-string? Great question Ken!

 

Um, errr....

Ever hear of Leadbelly and Stella 12 string guitars?

Ever hear of the Mexican bajo sexto?

Did you know that I got a letter from Frank Martin in 1965 saying that the Martin Guitar Company would never build a 12 string guitar? True... He died, and they did...   

It behooves luthiers to know at least some of the rudiments of the history of the instruments they build...I wouldn't expect one to know of my private correspondence, but knowing about 12 string guitars is kind of important if you're going to build one.

I do not make huge changes when I make my 12 strings.
My tops are a bit stiffer. I use deflection testing so I don't go quite as far.
For example, my standard SJ top deflects to around 280, my last 12 string
deflected to 230.   Also I have the X brace about 10% taller which if you
understand the cube rule, it quite a bit stiffer. The bracing pattern is the
same.

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Andy Z.
http://www.lazydogguitars.com

Like Andy I increase my X brace, tone bars and finger brace height. I also increase the thickness and height of my upper transverse brace and widen my upper transverse graft. I also add a rosette doubler

Is there a suggested top thickness? I normally build my 6 strings with tops between .110 and .120 (depending on it's flexability). Is going with a .130 or so the suggested top thickness?

Thanks for the tips on the bracing height too. I had already planned on building with taller braces, but didnt have any idea on how much taller to build them.

I dont want to end up with a 12 string that sounds dead from being over braced or overbuilt. I dont want it to explode from being built too light either.

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Reguards,

Ken H

I know I have seen a top with double -X bracing , I assumed it was for 12-string.the second set of braces ran paralell to the normal x- braces , lower on the lower bout , with the bridge plate forming a diamond ,tightly surrounded by the two x braces . John mayes in his video mentions seeing tops with three finger braces on each side and three tone bars I think he said he thought it was for 12 strings... Jody