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I made my first attempt at bending a cutaway using EIR. The pipe is 2" in diameter. I had a heck of a time trying to bend the small radius for the cutaway (1 1/4" radius). It seem the more I tried to bend the harder it became. I think the wood was becoming case hardened. Any recovery when this happens?

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A higher purpose for wood.
Rich Smith
Issaquah, WA

Hi Ricardo;

Seems there are a few bending questions popping up here. I will offer my pennies worth with regards to case hardening, if it helps. (case hardening pertaining to woods anyway.)
I don't know what thickness you're trying to bend but I've found a huge difference between .090" and .075" as far as a cutaway area, when I do a sharp cutaway, I bend both sides equally and after setting the sides in the form I mark and cut the side at the spot I start the cut away and then rebend it rather easily, (to keep the same grain pattern) . It could be that you are scorching the wood and this will be evident by black marks and the feeling of brittleness in the piece, if the resins are burnt or the oils in the woods are dried up, you're bending at too high of a temperature, try decreasing the heat and holding pressure in the bend as it "gives" to the iron, walking slowly over the heat in gradual increments as opposed to just setting it on the iron and waiting for it to bend, I will often drape a soaked rag over the iron and move the piece around slowly as it starts to creep and bend, but holding the bent pressure is a key to reducing spring back until it cools. Actually E.I.R. is what I'm basing this off of, as I find it really easy to bend to very tight radiuses at appropriate thicknesses, (say around .080".) If it's not bending for you too easily, I'd suggest thinning it slightly.

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Nehemiah Covey
www.coveysacoustics.com

Ncovey is right on the money!
Try again with the wood you have-the soaked rag is a great idea!
But I use a wetted veneer on the inside of the bend and a flexible steel sheet on the outside if i need to.
If you have thinned the wood ; go slowly with a constant but not over bearing pressure you should be fine-especially with Indian!

Mike

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Mike Collins

No expert advice here, but some anecdotal info. I was having trouble breaking sides when bending (mahogany). Thanks to John Hall for taking the time to visit with me and figure out that I was way over cooking the wood. He used the words "case hardening" in describing my errors. In any case, I was way too hot and way too long.

But once I figured out how to do it, I ran those case hardened pieces through my bender with absolutely no problems. So I'm just guessing, but I'd try setting it aside and come back to it another day after it's rested.

Good luck.

Miek

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Mike Lindstrom

Guys I thicknessed to .084 and down to .074 at the cutaway. I must of overcooked it. And I couldn't get a tight enough radius with a 2" pipe. In frustration I put it in my Doolan bender and ended up breaking the end off. Thanks for the suggestions.

_________________
A higher purpose for wood.
Rich Smith
Issaquah, WA