Bent laminations

[Dennis McDonaugh]

What is the maximum thickness to make stock for a bent lamination chair back? I made one using 1/16" thick stock and it worked great. It didn't spring back at all, but it took 7 layers to make one rung and I've got to make 8 chairs each with three rungs. I'd really like to cut down the amount of resawing I have to do.

[Doug Shepard]

What is the maximum thickness to make stock for a bent lamination ....
How I've figured out the answer to that one in the past has been to make test slats of increasing thickness out of the wood species you plan on using. Then try to bend each one to the radius you have in mind. When you get to the one that starts to make noises go back to the previous thickness.

[Richard Wolf]

Bent laminations are always trail and error. I'm pretty sure you could double the thickness without any problems. To avoid spring back try to avoid yellow glue. Use Unibond 800, or resorsinal, or epoxy. Also if the rungs are captured, spring back is not likely to be a problem.

Richard

[Dennis McDonaugh]

Okay, that's what I was afraid of, I'll try a few different sizes.. They will be captured and I'm using gorialla glue. I had a little trouble with the first couple of tries because I obviously used too much glue. It sure is hard to spread it over a large area and not use too much.

[Kirk (KC) Constable]

I try to get my bent lamination pieces down to around 1/8"...and I get very little springback. I'd suggest losing the Gorilla and getting some plastic resin...much better open time, and less mess. Also, depending on the width of the finished rungs, you might could cut multiples out of one glueup. Using Cabinet Master clamps (or Bessey/GS) and a good bending form, you can probably glue up an 9 or 10 inch wide lamination and rip it down later. Ripping the wide bendy thing may set off the saftey warning voice, but it's not so bad in practice.

KC

[Mark Singer]

I have made chairs using 1/4" and even thin plywood made to curve in a form. 2 layers of 1/4" baltic birch will make a solid back.

[Dennis McDonaugh]

Mark, KC, Thanks for the input. I settled on 1/8", I'll need a lot fewer pieces than I would at 1/16". I made a form out of MDF and can pull 1/8 into shape without an assist from the clamps.

KC, what brands are plastic resisin glues?

[Kirk (KC) Constable]

I use DAP Weldwood...comes in a yellow and white tub. Mixes with water, which isn't so bad once you get used to it. I get it at the local 'Do it Best' home center. Ace Stores might also carry it.

[Dennis McDonaugh]

Thanks KC,