I made my first test of annealing. First, I sooted and heated a 6" strip of alum trim (3/4" x 1") to test for amount of heating. I think I heated it too much, but not sure. The inside surface started to get a rough appearance and it "drooped" a little. I thought...too much heat? A longer piece on a flat surface would not droop though.
Then, I cut a longer piece to try heating and forming to the curve that I cut from a piece of 2x6 to the shape of my front roof curve, the tightest radius on the trailer. I sooted up the piece and applied the heat. The picture below shows the results. First, after bending it, I removed it and took a piecture of the amount of soot I had left after heating. Is that leaving too much soot from not enough heating? The first test strip had a little soot left, but not that much.
Then, I have two pictures of the piece on the test form. The curve is not as smooth as I would have liked, but it works OK. Maybe with more heating, it would have bent more smoothly?
At the right, is a picture of the piece from the bottom, showing the edge of the part that was flattened into the side curve. It looks straight enough. I cleaned most of the leftover soot off with acetone before taking the picture.
Any comments or suggestions for improving my technique?