Can steamed wood be relaxed?

[David Rose]

The form for the edging pieces that I steamed was cut to a radius of about 2" smaller than I needed. Would you believe the pieces relaxed all of about 1/2"? The Western Red Cedar seems more rigid than before steam bending. Even though the edging pieces are grooved about 1/4" for the gluing, I don't like the force required to get them in place. Any glue failure is sure to pop off an end.

Would slightly dampening the inside of the curve relax the pieces some? Or am I likely to have an unpredictable mess? I don't really want to use my extra pieces for testing, but I will if no one has tried this.

David

[Mark Singer]

David,
When steam bending or laminating curves in a form you must increase the curviture. It will tend to stabilize at less than the full cruviture....it is a little hard to predict and takes an educated guess. 15 to 20% loss of curviture is in range.

[David Rose]

Mark, I'm not sure I understand. The form should be smaller than the desired curve, right? I mean "springback" *is* opening up some (straightening out) isn't it? I made the form with a radius of 18 3/4" for a piece that I wanted to have a radius of 20 3/4". This was just guessing with no previous experience.

I just discovered that one dried piece is now a *smaller* radius than the form! I don't know how it could go that direction unless I misunderstood the thing totally. I suppose wood grain in the right direction might do that, but it is quarter sawn and cut with the grain.

Puzzled in Arkansas


David,
When steam bending or laminating curves in a form you must increase the curviture. It will tend to stabilize at less than the full cruviture....it is a little hard to predict and takes an educated guess. 15 to 20% loss of curviture is in range.

[Mark Singer]

David,
I really can't explain the results you obtained. There must be an internal stress in the piece that "wants" to warp tighter. It probably won't fit in the steam box again? Almost always there is a bit of "spring back" because the wood wants to remain straight.

[David Rose]

I read online tonight that a rare piece may spring inward. I did get a little spring back on some, just not as much as expected. I would need to build another steam box to get these to fit. Since I only have one form and no drying rack, I'm hoping to not have to resteam.

I guess you haven't tried to ease the curve a little with moisture on the inside. Most folks probably consider the piece lost if it doesn't fit well enough. On to practice on the spare pieces, if no one else has an idea.

Thanks

David


David,
I really can't explain the results you obtained. There must be an internal stress in the piece that "wants" to warp tighter. It probably won't fit in the steam box again? Almost always there is a bit of "spring back" because the wood wants to remain straight.

[Paul Downes]

Perhaps a little water and a hair dryer to heat it up might work to correct the bend? Just a thought. I have recurved bow tips using this method.

[David Rose]

Paul, did you soak the bow tip and apply pressure as you were heating it? I've tried it that way with no effect on the thicker cedar. Please explain your proceedure. I suspect something like this will work. I only need to remove maybe 5% of the curve.

David


Perhaps a little water and a hair dryer to heat it up might work to correct the bend? Just a thought. I have recurved bow tips using this method.