So I finished opening the angle on both longerons. A hard rubber mallet helped with the last fractions of a degree. Adding the twist was first a bit confusing as to how to measure it. I tried the electronic level but that didn't seem to do what I wanted. I read the instructions again and found the line saying it should lay flat on the upper surface of the angle. That was easier to verify than with an overly sensitive level.
When I thought this looks like a cakewalk I walked right into the trap and The Big Bend got me. This is the task where you match the lateral curve of the canopy sill piece as a template and shape the longeron to it. It looked so easy...
The technique suggested by Van's is to clamp the longeron in a vise, preload it at bang it with a rubber mallet right next to the vise. This works generally but I am still working on a part a few inches behind the start of the bend where the curve is most drastic and I can't avoid bending it outboards too much. I don't know how to avoid this. Dave seems to have been much more lucky with this step as his looks just perfect. As he didn't say anything as to how he did it I guess the Van's method just worked for him.
I'll try my luck later today again and see if I can get a license to practice as a blacksmith now as well.
This is how far I got with one longeron. Not happy about it...
I didn't use the mallet. I put the angle in the vise (protected from scuffing with pieces of scrap wood) and just bent it by hand. Bend a little, loosen the vise and move it an inch or so to the left, bend a little, loosen the vise...
ReplyDeleteI'd lay the template over it as I went to check progress. Be careful with that, though. I bent the second one the wrong direction because I used the wrong template piece.