The Luthier Community

Hi Folks, I'm building a body form and would like some input. I'm making it from 3 pieces of 5/8" softwood ply and a spacer between. My question is will this be enough surface, or will the sides "bow" in the gaps?




I will glue it up so the thickness will work for dread size.

Hey kb1fvx,

I haven't build with a form like that, but all things considered I can't think it would pose a problem.

By the way, what is your name?

Erik

Edit: Ah, I see it is Mike.

Howdy, Mike!

I think you're fine with the empty spaces in the female (assembly) mold. And, I see many builders that use female molds that are not as high as the instrument sides.

Now, for the male (bending) mold, I have seen folks getting away with 2 outside pieces and rods between them, but to give myself some insurance, I want a solid mold supporting the entire side. A solid mold may help to keep some cantankerous sides from rippling during bending.

Dennis

Mike around the waist/side/tail and neck block area, should be ok as long as you do not over tighten the sides. If your mold is not 100% inline it could result in a split or twist. But mostly does not present a problem.

Thxs
Hugh

Thanks for the insight. I think I'll use the cut-offs to make the spreaders with either turnbuckles or a spring assembly. (will have pics) For now I'm making a propane fired bending pipe to see how that works for me. I'm sure somewhere down the road I may make a bending jig for the harder to bend woods.

Lookin' good, Mike!

And as you've no doubt noted, any question will getcha solid and timely advice!

Lookin' forward to it!

E

Mike,

I build my molds in a similar fashion to keep the weight and material cost down only I use just the upper and lower. As stated before, you should not have a problem as long as your inside caul does it's job distributing the pressure.

The bending pipe: I made and electric one using an old mobile home water heater element and two timers...just off/on/off repeat cycles to regulate temps, The torch works ok but hard to regulate temp. Some builders are using an electric Bar-B-Q charcoal starter and bending it to fit in the pipe.

And order some supersoft to help keep the wrinkle out of your sides. I spray the wood the night before bending and it helps! Even some more flatsawn woods bend with a lot less cupping.

And this is what I ended up making. Its not pretty, as its all reclaimed (yes, the screws to).
I did splurge and buy a set of clasps. I used plywood as filler only for strength in the lower bout area. I'm not sure how much pressure I'm gonna have to use to keep the sides still, I'd much rather over-build than under-build it.
Now, onto the caul.