Wednesday, January 15, 2014

Trust the Jig

Perhaps due to my recent visit to a plywood factory, I have been interested in plywood and its properties. I wanted to try bending legs for a chair, just to get a feel for the material and how it works. This being my first time bending plywood, I made some foolish mistakes. The first one was to cut the strips along the grain, which made them much harder to bend. I used 1/8 inch, which was the thinnest I could find, but it was still pretty tough.

I soaked the strips in a bath for a few hours to loosen them up. 

When they were wet, I clamped them in position and left them to dry out a bit. They took a long time to dry, though, because they were clamped together.
After a day or so, I took them out, glued them, and clamped them back. The glue on the top of the leg was dry after a few hours, but the bottom, where it touched the base of the jig, was still sticky. I took the piece out of the jig and clamped it separately. But, here was another mistake: I was afraid the leg would "relax" and loose a bit of its curve, so I reinforced it with string. The picture below is just a mock-up so you can see where the string was.
I learned, afterwards, that I hadn't pulled the two legs equally, so as a result they had different curves. 

Lesson learned: trust the jig! I think they would have been just fine if I had clamped them without the string. I guess my chair will have to wait.