The aluminium I bent was 0.038in or about 1mm thick and the longest bend was 310mm, just over 12 inches.
Clamping handyman bench
Wood saw and plane
Hot-melt glue gun
Two shelf boards (mine were melamine-faced chipboard)
An old car seat-belt
In bending, there are two big problems – holding the metal against the bending nose, and stopping the metal from sliding out of the press. Also the hinges have to be very strong.
As I haven’t any welding gear I wanted a hinge I could use with wooden boards. They are old melamine faced shelf panels. I connected them with strips of seatbelt webbing fixed with hot-melt glue. The belting is in tension when it holds the top board against the workpiece. These pictures show how it works.
A safety thought. If the strips beak away from the glue it would collapse and that would be when I am leaning on it pretty hard, which could be nasty. So I nailed down each strip of belt with a carpet tack. If the glue comes unstuck the belts should rip gradually and lessen the danger. I put the tacks away from the ends to allow a long tear before there is nothing.
I found it was tricky to hold the board and the workpiece, and it sat too far down in the vice. So I nailed a couple of bits of thin ply to the top edge of the bottom board to stop it falling down. And I used an offcut of wood to hold it a couple of inches above the work surface.
I found I needed to over-bend the aluminium by about 30 degrees since it springs back. So the nose needs to be made pointed about 30 degrees. You can why the whole thing needed to be raised up in the vice, to allow for it to bend beyond 90 degrees.
I sometimes found the nose tended to slide down. So I clamped some non-slip table mat between the workpiece and the bottom board. Here you can see one of the last bends being made. You can also see extra wood was needed to clamp the workpiece without squashing the sides I had already formed.