Recently I needed to steam bend some American Ash for a prototype chair commission. I am not a fan of steam bending kiln dried lumber, but due to time restraints this is all I could find. The lean of the upper back posts is 2 inches from vertical. I made the clamping fixture with a 21/2 inch lean for the expected/guessed spring back.
When steam bending thick material a common rule is for every inch in thickness means at least one hour in the steam box. I broke the so called rule for it took 4 hours in the steam box to bend the back posts in position. I allow the bend to set for several days before removing them from the fixture. The spring back was almost perfectly estimated.
|Pine steam box screwed together. Dowels to hold parts. |
A wallpaper steamer was the tool of choice.
|Forms with dowels and folding wedges to hold the bend in place.|