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I have just started on my next guitar and I used a side profile template that I made for my first guitar (which I think ended up to thin) 3" and the neck 4" and the tail. Previous guitars I have just added an inch to that template before bending then used a radius dish to get the proper depth.

So last night I decided to try some thing different. I ran the flat edge of the the sides through my jointer and did the same with my scrap pieces that I cut off of the original sides. I used a thin B/W/B purfling and joined the pieces back together with LMI white glue. Now I have a 2 piece side with a thin purfling line towards the top.

After I had done all this work I started thinking this glue joint is going to come apart when I go to bend the sides. I don't know what temp LMI glue breaks down but I am sure its under 300 degrees. I am using EIR

So here are the questions is there a low enough temp I can bend the sides and not cause the joint to fail?
Is there another way to get another 1/4 to 1/2" of depth during the build?
Or just use these are scrap and star over?

thanks
Richard

Richard as you suspected the LMI glue will start to release with temps as low as 145F. Since we bend sides at temps often twice 145F and then some depending on the species of wood I strongly suspect that the glue joint with come apart during the bending process.

I know of no way to bend sides without heat beyond finding an old bottle on a beach that when rubbed a Jeanie appears and grants you three wishes....

Sorry I don't have a good answer for you...

The only suggestion I have it to bend them and then reglue them. I'm sure it would be tricky.

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

Todd Lunneborg has made multi-piece sides; he used CA and bent very carefully. There are hi-temp epoxies that would work, as well.

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Bob Garrish
Former Canonized Purveyor of Fine CNC Luthier Services

You should be able to do it. David LaPlante bent the sides of his #90 guitar with the meander pattern around the center of the sides. The meander essentially made this a 3 piece side. He used a cloth back-up strip as additional support, but he glued the pieces together, then bent the sides. If you want more detail, check with David. I'm sure it takes some fiddling. I believe he bent it on a pipe, so he could bend some, then hold it together while it cooled and the glue re-bonded.

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Waddy

Photobucket Build Album Library

Sound Clips of most of my guitars

I ran some test pieces a few years ago when I wanted to duplicate some old (nineteenth century) purfled sides. The most successful ones had the purfling inlaid rather than sandwiched but I was able to bend pieced sides successfully by reinforcing the joint with tape, lots of tape, especially at the waist. I used a Fox-style bender and was careful to have good contact between the wood and steel slats at all times. The tape made a mess and I didn't really trust the joint afterwards so I didn't pursue it.

At the risk of being an annoying know-it-all, it's kinda important to think through new procedures and run some tests before attempting them with valuable materials ...

I'm not sure, but I believe I read somewhere that polyurethane glue actually hardens with heat rather than softens. Maybe it could work in your situation?

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Alain Moisan
Former full time builder of Acoustics, Classicals and Flamencos.
(Now building just for fun!)

Maybe Howard Klepper will join in...he has done it as well!

Shane

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Canada

I get some separation from bending, but then I put it back together, and back the joint up with an inner side.

Back to the OP's question: Yes, you can stretch the width of your sides by 1/4-1/2". You do it by extending your liner blocks out beyond the sides. The gap will be filled with binding.

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Howard Klepper
http://www.klepperguitars.com

When all else fails, clean the shop.

I have done some and had luck with 2 methods. 1 was using CA. On hog I used tite bond and used tape to hold the joint together when bending. It came out without a problem. Could have been beginners luck. I think HHG would work ok as it will reset . The tape held my joint and I think that was the key.
Like Rick pointed out , try a scrap first .

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John Hall
blues creek guitars
Authorized CF Martin Repair
Co President of ASIA
You Don't know what you don't know until you know it