When I built my Haighs Chocolates delivery van I bent the 15mm wide crescent mouldings cold, just as it came.
They took some doing around the side window, but I managed it without any second tries.
The D & F roadster is a different challenge. These bends are much sharper, and I was thinking the mouldings would be easier to work with if the section to be bent was annealed. I am looking for advice on how to do this.
Hope someone can help.
Allan from down under.
Allan, I think you need to use 50 series Aluminium. It is bendable. And I think you use a torch black sooty and heat the Aluminium. Try a sample and see. Scott
Not hard to do, rub some soap onto the aluminium, warm it up with a blow torch until the soap turns black, cool and jobs done, have a play with some that's spare and let us know how you went.
I bend moldings as milled. Use a channel form.
Ken, I used a channel form on the van for the side window curves. The extruded moulding seems rather tough, so I thought softening it may help. Perhaps I should soften and use a channel form. There is one really tight bend where the mould transitions from horizontal to vertical on the side panels which I am concerned about.
How do you draw your diagrams? They are most helpful.
Allan from down under.
I heat it and rub it with a very small dry stick until the stick draws on it like a pencil. Then let it cool in still air.
Annealing will certainly make it easier to form but it's difficult to get it annealed evenly without an oven. Spot heating may leave hard areas if you're not meticulous. The annealed areas will bend long before the hard areas and you could end up with what I call jogging. It will look like a bunch of zigzags or curved and straight areas along the bend.
The above drawing is for bending curved material on edge. When bending on the flat side around an outside curve, you will need to include the shape of the material in the form or it will tend to collapse or flatten out. You will need to include the opposite side support also. In other words, the material will be "sandwiched" between the forms (or dies).
In your photo above where the molding transitions from a flat form on an outside radius to the vertical on-edge shape, each bend is treated separately and with different forms. I would do the vertical on-edge bend first simply for ease of material handling. Then form the outside (flat) form.
Oh, the (crude) drawings are done with Microsoft Paint. It's quick and easy to use. Just break the objects down into simple shapes--Lines, circles, rectangles, etc.