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So - while reading an older edition of Guitarmaker - I cam across a reference to Larson Guitars having laminated braces, and that this treatment of their braces being somewhat accountable for their "magical" tone.

So, I'm nothing if not curious and a bit A.D.D -so I got to thinking - maybe on the next guitar.

Anyone have any experience with laminated braces? If so, what structure would you recommend? laminate thin (vertical) pieces of spruce, keeping the grain orientation perpendicular to the face of the top or the back? Try some laminations of wood combos? Spruce/mahogany/spruce sandwich?

Thanks! As always, looking for trouble .....

Some Larsons had the main X laminated 3 parts, spruce, rosewood(ebony?), spruce.
A very famous Canadian guitar builder lams CF in the center of his main X.

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What David said - Mario is the famous Canadian builder and interestingly he prefers Engleman with his CF in as much as his testing showed that other spruces were too stiff in combination with CF. The other "ah ha" moment for me when I read about Mario's bracing was his view of using CF for it's memory. If CF's memory is important to Mario this says to me that he does not want absolutely stiff braces instead favoring braces that can flex to his desired degree but that still return after the top moves.

Yeah, that was a real stroke of genius. The whole problem with building light is that you have cold creep over time deforming everything...but if the materials don't creep...

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Bob Garrish
Former Canonized Purveyor of Fine CNC Luthier Services

Thanks all -

Interesting - laminating with CF and Spruce sounds like it would perhaps reduce mass while introducing more memory, while laminating with ebony or rosewood certainly wouldn't reduce mass, but would increase stiffness for sure. Right?

Last question - the laminates would be vertical in orientation I take it (in other words, like a sandwich standing on the back on the soundboard "on edge", with spruce, other, and spruce each having a glued edge to the soundboard??

If you go to Mario Proulx's website he shows how he goes about laminating his braces. I dont think he mentions it but it looks as if he has the grain oriented just as you suspect. Just go through his step by step buildup pages.

Warren.

Why would CF by itself reduce mass; it is actually twice as heavy as rosewood. In the end it all depends on the dimensions of the brace, thickness of the center piece etc.

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Simon Fay uses "T" braces. I guess they'd be considered laminated. Here's a link to his braces on his website.
http://www.fayguitars.com/guitars/features.html
I don't use, or plan on using laminated braces, but the options are interesting.

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I didn't mean to say it, but I meant what I said.
http://www.brackettinstruments.com/

Like Alexandru said, a brace of the same dimensions but that has a CF laminate in it will weigh more than a strictly wood brace.

I've been thinking about making I beam braces (for my banduras) by taking a really thin sheet of CF and gluing squares of spruce on the top and bottom once I shape the CF sheet to it's final shape. Banduras have a carpload of downforce on the bridge and I have lots of cold creep issues. The issue with that for guitars is that you can't really tune an I beam by carving.

Edit: perhaps leaving it an inverted T brace might allow some tunability simply by shaving down the CF - hazardous but it might work.

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Who said that they were the same height, or thickness? What Mario is doing is gaining control of how each brace performs, by adding a center laminate with known properties, one of those being that it has a memory for it's original position. Over time the spruce would succumb to the tension of the strings, but the CF will not.

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Waddy

Photobucket Build Album Library

Sound Clips of most of my guitars

If the braces are laminated and won't deform over time, or relax into a new shape, could you use laminated braces of say 25 foot radius glued to a 18 foot radiused rim set, so that when they are clamped and glued into postilion so that you've got stored energy in the top sort of like a spring?

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Formerly JJH

I learn more from my mistakes than my successes

I was think on giving the CF ago on one of my next builds too. While Mario uses CF he also doesn't at times too. I ask him about it from his videos and he says he uses a lot of variations too. The guitar in gluing the back with hide glue doesn't have CF in the braces. I haven't read the latest artical but in the old MIMF artical he says he uses it mainly for the memory and not for stiffness. He also says he used .020"-.022" as the .030" was too stiff. I believe he makes the braces as usual and laminates the CF in the middle. Check out MIMF library I remember a picture or two. I don't think that's on his website anymore either. The last time I check it seems he has redone his site and the build pages weren't there. At least I didn't see it. I'm going to have to get that guitar maker issue and read what he said about it since that Library discussion might be out dated. You might want to over to MIMF that's where he is.

Isn't that kinda the idea using radiused braces with a flat rim?

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I didn't mean to say it, but I meant what I said.
http://www.brackettinstruments.com/

Yes, but with standard non laminated braces the wood would quickly relax into it's new shape and lose any stored energy. Also as an aside my first guitar was 25' radius to a flatish rim (I angled the blade in the plane body fractionally) and now 6 months down the line I can see as the top has pulled up slightly the flat linings around the top of the guitar.

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Formerly JJH

I learn more from my mistakes than my successes

Mario has videos? For sell?....or videos he posted on the web or his website?

This subject intrigues me. It would be a pain to work with CF laminated braces......more work to glue up and much, much more work to profile as teh CF is so tough......not to mention the dust. If some experienced luthiers are doing this there must be a benefit as it appears it's much more work.

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Formerly known as Adaboy.......

I like the lamination idea, but wonder about the lamination separating in the future (may take many years), due to the dissimilar materials moving at different rates and fighting each other with humidity changes. I suppose only time will tell.

I have been experimenting with Larson laminated bracing on both 6 and 12 string Stahl 15" bodies. Not wanting to get real techie with CF and all, I have been using BR, African blackwood and maple for the centers with bear claw Sitka for the spruce lams. I have the boxes together, and they tap out very nicely.
I did get a little techie with installing some CF rods similar to Larson's Prairie State metal "tone tube" in the 12 string, and did something akin to tone bars on the top with tunneled crossbracing. We'll see how they turn out...

Mario has the gluing the back on 3 minute video on youtube and trimming the back with a 1/4" zip bit and a few with him playing some guitars. They are all about 3 minutes because that's how long his camera will record before stopping. He also pre shapes his braces because the CF is tough on chiesels.I don't think if the braces are epoxied together that you will have a problem with the braces coming apart. Go to MIMF the videos are in tools and in glue sections.

What's the point? Wouldn't a triangular brace give a better strength to weight ratio with less work?

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Jeremy Douglas