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Hey guys,

One of my plans for this current build is to fool around with CF tow capped bracing - to help out with cold creep....

I am thinking about the 3K tow....

Questions....
1. Is the 3K tow the right stuff for capping braces or should I go with the 6K tow?
2. Is say "Aircraft grade" tow the right stuff - or is there a better choice? I know that some of the stuff advertises long, parallel fibers, etc....
3. Where do you buy the stuff... or is there a preferred vendor you guys like?

Thanks

Truckjohn,

Can't help you with what size TOW to use without knowing more about what you are trying to accomplish. 3K used correctly can be strong enough, but so is spruce without the carbon. Used incorrectly, even 50K tow could be too weak.

Carbon TOW can be quite challenging to work with. It would be much easer to cap braces using unidirectional laminated plates.

ACP composites is a good source to work with.

uni plates:
http://www.acpsales.com/Carbon-Fiber-Un ... nates.html

Tow:
http://www.acpsales.com/Tow-and-Cords-c-4958.html

Twill plates for mario-style bracing:
http://www.acpsales.com/Carbon-Fiber-Hi ... heets.html

-jd

I have been going through Gore and Gilette's "Desing and Build" books - and one of the techniques is to epoxy a strip of CF tow in between the soundboard and the brace, and another on top of the brace to help with cold creep resistance...

There are several good pix on Trevor's site of how he does it.

Thanks

John, contact David Schramm. He makes Smallman style guitars, and uses tow to cap his lattice braces, as does Smallman. He might even have some tips on his website. Builds classicals, but still pertinent.

_________________
Waddy

Photobucket Build Album Library

Sound Clips of most of my guitars

Like Todd, I think that Mario's approach to using Carbon Fibre to resist creep is practical and well thought out. I've been using it for the last 4 or 5 instruments and am very pleased with the results.

When you use Mario's approach, do the braces end up with similar dimensions or are they significantly shorter to offset the added stiffness from the carbon tows?

+1 on comments from Todd, JD, and Rod. Tow is a pain to work with. CF is much much stiffer than wood -- if used as a cap where it has max stiffness contribution, it would be difficult to get just the right amount. And as a cap, the underlying wood still can creep in shear.

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David Malicky

I have reduced the width to 1/4 in from 5/16 without any apparent loss of stiffness and generally use the same height, but adjust it minutely when I am tuning the top. In my guitars I use the carbon fiber in the "X" and in a small lateral brace below the bridge-plate.