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back bracing question?
http://w-ww.luthiersforum.com/forum/viewtopic.php?f=10102&t=11933		 Page 1 of 1
Author:  gratay [ Mon May 07, 2007 9:29 am ]
Post subject: 
I have decided to build my back bracing as per scott antes om plans.....so 2 tall braces and 2 lower wide braces. no other reason than i already made them and cut the back reinforcement strip for this size as per the plans before noticing that everyone uses tall thin braces pretty much....
so, the dimensions on the plan for the lower wide braces are 19mm wide x 6mm which i cut and then sanded the radius in the the 15' dish...
I am now wondering whether these will make the back stiff enough because after sanding the radius they are quite flexible.... hence one of the reasons for keeping all narrow tall braces i assume...
So I referred to cumpiano/natelson book and noticed on his wide braces the height is more like 12mm....but his back looks braced quite heavy to me.....

what to do?
I'm just wondering what peoples thoughts are on the dimensions of wide braces as far as an OM goes and whether mine may be to light ?

cheers grant.
Author:  Bill Greene [ Mon May 07, 2007 10:32 am ]
Post subject: 
Like Hesh, I go with two thin/tall and two short/wide. I haven't seen where "most" people go with tall/thin. In fact, of the 2-3 pro builders I know, they also go with 2/2 as described.

I guess everyone has different reasons for what they do.
Author:  tippie53 [ Mon May 07, 2007 3:11 pm ]
Post subject: 
Todd is 100% correct. Antes isn't even close to the actuall martin spec. The back braced as okay but the top is off.
    I like the lower braces vintage. It allows the back to have more influence to the guitar. The modern braces will add stability to the backs and make them stiffer and more secure but I prefer the tonal inference with the flat braces
john hall
Author:  gratay [ Mon May 07, 2007 3:39 pm ]
Post subject: 
ok......cheers guys for the valuably input....
if the antes plans are over braced i think i may go ahead with the back bracing as per the plans as john and todd suggests and do some research about the top when i get to it....
I am looking forward to hearing what the tonal inference is with the flat braces .....
so the wide/flat brace specs i have being 6mm at its thickest in the middle of the brace hasn't rang any alarm bells with forum members yet which is encouraging.

Hesh ....your back looks great.....another git I'm looking forward to seeing..

I will post some progress pics once its all glued up.....
Author:  bob_connor [ Mon May 07, 2007 8:32 pm ]
Post subject: 
Hi Grant

We've just changed to this style of bracing on OM's after a discussion I had with Colin Symonds and Dave White.

The X braces certainly hold the radius of the back better.

We're just about to string up 2 OM's that have ladder bracing (all tall and thin), so I can't really comment on tonal differences until they're all built.

(trying to compare a Rock Maple guitar with an EIR one will probably be like comparing apples and oranges anyway )

I think what you are doing will be fine.



Cheers

Author:  Kevin Gallagher [ Mon May 07, 2007 11:36 pm ]
Post subject: 
    I like the two tall and two wide bracing set on a smaller bodied vintage
style instrument, but use four taller narrower braces on my standard
models.

    The problem I have with the shorter wider braces is that they can
flatten out over time and lose their original arch to a degree. The strength
of a brace comes from the height of the quarter sawn grain.

    One benefit of the more narrow bracig is the reduced surface contact
are and subsequent damping that can occur. That's why Martin switched
to four higher braces some time ago with the exception of some vintage
models.

Regards,
Kevin Gallagher/Omega Guitars
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