Quote Originally Posted by Mike King View Post
Kiln dried lumber is not an issue with bent lamination. You need 1) laminates that are thin enough to be able to bend around your form, 2) an appropriate glue that has a hard glue line (and likely sufficient working time), and 3) sufficient pressure distributed over the laminates to bend the laminates gap free around your form. I've constructed a number of chairs using both steam bending and bent lamination techniques with kiln dried wood.

I gather that you also tried steam bending. A few questions about that:

1. Did you soak the wood? When I bent 10/4 kiln dried cherry, I soaked the blanks for 7 days before steam bending them.
I thought about soaking them, but had no way to do that. I thought about a blow up kiddy swimming pool. Couldn't find any PVC pipe with sufficient diameter.
2. Did you wrap the blanks in plastic when you steamed them? This is a technique I learned from Michael Fortune. Wrapping the blanks in plastic helps to retain moisture in the blank as you steam it and increases heat transfer to the blank.
No. Didn't wrap them in plastic.
3. How long did you steam the blanks? I'm at 5400 feet so I can't get my steam box above 197 degrees. As a result, I steamed the 10/4 blanks for 4 hours to ensure that they were very well heated. I've also bent 9/4 kiln dried walnut at 8200 feet -- sufficient time soaking to raise the moisture content of the blank and sufficient time in the box to heat the lignon is needed to be successful in bending.
I'm at sea level, so I was able to get to 212 degrees F. I steamed them for about 1 hour after they reached 212F, so closer to 2 hours total time.
4. Did you use a strong compression strap? Steamed wood will compress considerably, but if a compression strap doesn't tightly hold the inside of the stock, the blank can separate or crack. The Veritas compression strap and fixtures (from Lee Valley) are very good--they were designed by Michael Fortune, and come with a guide to steam bending that was written by him.
I couldn't find the Veritas compression strap I had from years ago, so I made my own.
5. Did you put your bent parts on a drying form? Once bent, the part needs to be clamped to a drying form to dry. It takes 1 to two weeks for the part to return to equilibrium moisture if it has been properly steamed. Removing the part from the drying form generally leads to a minimum of excess springback or, for that matter, the part looking nothing like the form.
I kept the bent parts (2 at a time) on the bending form for 2 days after steaming. Had large amounts of springback. I then tried taking those steam bent pieces and epoxying them together for 48 hours while being clamped with the clamps shown in my pictures and with the ratchet strap on the bottom. Had less springback this way, but still some small gaps in spots between them

Mike
So I've taken apart my bending jig and will now work on much smaller pieces that will be glued together. Your advice has been great, and very appreciated, Mike (and others), but this just didn't work in my hands, despite more than the college try (and significant expense and wasting of wood). Oh well. How we learn, sometimes the hard way.