Steam bending

[Jeff]

Just starting to explore steam bending and the learning curve is steep.

I made a new bending form to try (24" w with a 3" h center arch) and several 3/4" oak dowels to keep things in place on the outside face.

Poplar is a poor bending wood but it was on hand (BORG stuff). Steamed 3 pieces, 1/4" t, for 1 hour and fought them into the form to make the bend at the outside part. Removed them after 24 hours and there's about a 1" springback from 3".

​

Arrrggghh, but I expected the springback. I've rived some fresh green wood from a red oak log and I expect that to bend better and hold the shape with less springback. More later on the trials and errors.

 

[Wyatt Co.]

I see some delam. I think your springback issue could be adhesive related.

[Edit]

Nevermind, I see you're just trying to bend multiple pieces at one time. Not glue them together.

Any time you stack your pieces, each piece stacked on top of the other has less curvature than the one beneath it.

Also, looking at the pieces in your form, they're not tight on the ends. The springback is less than you think.

Use wedges under your dowels.

 

[Phil S]

You will have MUCH better luck with non-kiln dried wood. Partial air dry is ok but kiln dried will always be a problem.

 

[Jeff]

Yep! I'm going to make a few wedges to use between the bent piece and the dowels to tighten things up, particularly on the outside wings.

The springback is less than you think.

Sure, it's probably less than the 1" that I measured. Still not a show stopper.

 

[Dutchman]

"Poplar is a poor bending wood but it was on hand (BORG stuff)."

Ash or Beech will work better.

 

[walnutjerry]

"Poplar is a poor bending wood but it was on hand (BORG stuff)."

Ash or Beech will work better.

White oak, red oak, ash, hickory and hackberry will give the highest rate of success in bending-----------according to the book I have. I think white oak has the highest success rate.

Jerry

 

[Jeff]

You will have MUCH better luck with non-kiln dried wood. Partial air dry is ok but kiln dried will always be a problem.

That's what I've read here (Danmart77 and others) as well as elsewhere (Michael Fortune, Lon Schleining, Curtis Buchanan, etc) in addition to choosing the right woods to bend.

Kiln dried wood has the lignin fibers set because of the high temperatures so those fibers don't want to stretch/compress as easily but a mild bend radius can still work. The bendability has nothing to do with the moisture content of the wood and soaking it in water is not useful.

Interestingly, Scott Smith says that he's getting more requests for "steam bending wood".