Official Luthiers Forum!

I bent my first set of sides and I'm pretty happy with the results. I bent them freehand on the hot pipe and then put them in a mold to let them settle. Now here's my question. I'm happy with the curves I've got, but in a couple of spots, there are gaps of 1/16" to 1/8" between the sides and the mold. Is that within reason, or should I touch things up on the hot pipe again to get a more precise fit?

Again, thanks in advance for everyone's help.

Steve

are there flat spots .. or are the curves smooth ???? if smooth, you can likely press the sides out to meet the mold. If flat, you need to get the curve right first.

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Tony Karol
www.karol-guitars.com
"let my passion .. fulfill yours"

I'd go with it as-is Steve, as long as the curves are nice and there's no ripple or bumps. I see gaps bigger than that using a Fox style bending machine with heating blanket....
Added: I'm in the process of modifying my bending formers to overbend the sides a little to make the sides fit the mold better after they are bent.

Cheers,
Dave F.

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Cambrian Guitars

"There goes Mister Tic-Tac out the back with some bric-brac from the knick-knack rack"

Personally Steve, I would just touch up the area's that are 1/8th out and leave the others. As long as the sides are parallel with the mold, to me at least, is the important thing, if the final soundbox isn't quite the same shape as the mold doesn't change the sound. I wouldn't get too hung up about producing a perfectly shaped box (it is being hand made not falling off the end of a production line), as long as there aren't any definite ripples and they look like nice smooth curves & everything visually "looks" right......Just my opinion.

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Nick Oliver

http://www.oliver-guitars.com

Steve, I believe that the sides should be snug against the mold. If need be, use spreader bars (turnbuckles work great) and shaped cauls to push the sides into the mold. Not a hard thing to do.

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Jim Womack

"Be thankful we're not getting all the government we're paying for. "
Will Rogers

The main thing, for me anyway is to not have ripples. If they're smooth, but just not fitting exact use spreaders make them fit.

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

There is a secret to this. You want your side set to be a tad longer than the surface length of the mold. Take a piece of tape and lay that onto the mold. Cut clean at the center line. You now know the length of the molds surface. Ad a 1/8 per side so that you have a good 1/4" longer side set than the mold needs. The object is to see the waist just lift about 1/16 to 1/8 off the mold. The spreader will push the sides against the mold.
Of the people that take my class they can vouch how tight the side set will get in the mold. The need of upper and lower spreaders is eliminated and the sides will flush off against the mold . This is how you can get a repeatable shape from your mold. I gave this same demo at ASIA in East Stroudsburg PA. Using spreaders will help but this is assure a proper shape from the mold.

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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

Hi John, Thanks for posting this info. I have been trying to figure out how to do that. I'm looking forward to trying it next time. Sounds almost foolproof.

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RJS