Steam-Bending Plywood ...

... does not work. May 15, 2011

I'm working up a proposal for some curved bookshelf sections. I'll be working with 3/16" plywood and plan to bend it to a 37cm radius curve using a steam box and drying rack with end blocks. Before building the rack, I plan to experiment with straps to get a sense of the springback. Will steam bending ply work without pressure on a solid form? Are there any pitfalls with plywood sucking up too much moisture and/or steam screwing up the glue between the laminates?

Forum Responses
(Laminate and Solid Surfacing Forum)
From contributor J:
I've never heard of steam bending plywood. I'm about 97.8% sure that it won't work.

From contributor C:
Consider using bender board and laminate something to both sides after bending. Usually veneers are used, but if a gentle curve, that thin plywood you were thinking of might work, but only if you can bend it by hand to that radius. Don't steam it. Steam won't do anything good for you with plywood. It's only for temperate hardwoods known to steam bend like ash, oaks, elm, hickory, maple, beech and a few others. Plywoods are not often made from species that respond to steam bending, and their laminations prevent the compression you need to force to the inside of the curve when you steam bend. Still, anything thin enough can bend, you just might not be able to push it further with steam. Only experimentation and experience can show you what kind of springback to expect.

From the original questioner:
Alright gents, you've talked me out of it. Simplest might just be to create the curve like a standard laminate from the get go: two faces with something in the middle. Cheers.