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Getting geared up to build an all mahogany 12 fret 00 and was thinking of using a 2 piece, 'pinch' type bending form to shape the (steamed or soaked) wood for the sides. I've got limited (and long ago) experience heat bending sides and I don't want to go to the trouble and expense of a Fox type bender for what may be a 'one-off' deal. Anyone use this type of form? Tips? Tricks?

I don't know what you mean.

Glue up 3 pieces (4.5") of 2x10 about 24" long then trace the outside shape of 1/2 the body centered on the edge of the glue up. Bandsaw the shape then saw off about 1/8" of the piece that you cut out - you now have a bending form. Soak or steam one of your sides, put it on the form and gradually press it into shape on the form using bar clamps. I used this method years ago but haven't seen it lately - maybe I've got the name wrong. Not useful for cutaways.

You can use 1/2 of a building form for this, I guess.

So, what you are saying is: get the side hot enough first, then drop it in and clamp the whole thing before it cools down? Seems like it would cool down too fast. But, if you did it before, that's great! I would like to see that. We could save a lot of money on Heat Blankets!

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Pat

The main thing to that method is you keep the wood relatively warm and saturated while bending. Wood bends more with a higher water content. You might want to try some liquid fabric softener on the sides. Soak them overnight with it at 100% then when you heat them have a fair amount of fabric softener in your water. It is a poor man's Supersoft II. Or you could buy a small bottle of Supersoft.

If you're worried about cost and time, probably a 2$ chunk of pipe from the scrap yard and a propane torch will set you up.

Years ago I made a "D" inside form out of many layers of particle board over 10" wide. I coated it with water resistant paint of some kind. Along the perimeter were a screw eyes and eye bolts used to clamp slats down to the form. I had my clamping slats spaced very close to prevent cupping. Because the form was wide enough I could bend both side at the same time. The side material was actually boiled in a long tray which I also fabricated. Once boiled the side material was extremely flexible. It took a couple of days for the set to completely. I successfully bent Rosewood, Mahogany, Maple and Black Walnut using this system.

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Ken Cierp

http://www.kennethmichaelguitars.com/

I assume the "pinch type" refers to penny pinching. A lot of my tools are that type.

Of the woods we normally use, mahogany is one of the hardest to bend successfully. I wouldn't want to be trying to bend it with a suboptimal setup.

Ed wrote: "If you're worried about cost and time, probably a 2$ chunk of pipe from the scrap yard and a propane torch will set you up." I'd agree--that approach would probably end up being less time and hassle and you'd be less likely to break your mahogany side.

If you don't already have a propane torch, I'd recommend getting an electric charcoal lighter. I use one of those jammed into a scap of aluminum pipe, adjusting the temperature with a router speed control. It was cheap and easy to make and works surprisingly well.

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Tim Allen
"Never hurry, never rest."

Mahogany can kink on you instead of bending. I would use a more conventional bending method than what you are planning. Not spending money on a bending setup is a false economy if you mess up several sets of sides trying to use a method that winds up not working.

I believe Mr. Sloan was an advocate of this method back in the 1970's, but a quick search fails to turn up many that still use this male/female mold approach. Given that hot pipe and various blanket benders are used in a broad range of commercial and hobby builder's shops, the dearth of luthiers employing Sloan's approach to side bending may serve as an assessment of the relative merits of at least the three bending methods mentioned.

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A constellation only takes shape when one maps the whole.
- Beth Brower

In 1975 I had Sloan's book and a half outside form made of plywood.
Boiled the Birch in a long tank and clamped the piece into the form.
Just barely worked.
Birch would have probably bent in just cold water.

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https://www.facebook.com/profile.php?id=100008907949110

Ditto. Pipe with a torch...or heat gun...or charcoal starter is a cheap way to bend guitar sides. Its really much easier than it looks

Yeah, I've got a pipe bender rig that I haven't used in years - maybe I should dust it off..........