Originally Posted by Timon
How did you do the 1/8 slot using a C channel for the panel to slide in?
My son-in-law welded in a piece of 1/8 x 3/4 flat stock to create a 3/16 wide slot.
You could also use VHB tape to bond on a length of 3/4 x 3/4 angle. In retrospect that would have been easier. The smallest roll of tape is much more than you need to stick the frame to the roof of the trailer.
The frame has to be bent to match the curve of the roof before it is stuck down. If you used VHB tape and angle to create the slot you would want to bend the C channel and angle separately then tape them together, then bond the assembly to the roof.
This whole thing could have been made from wood too. Trim the bottom of the side rails to match the curve of the roof, leaving the top edges straight, then rip the slot on a table saw. A couple of coats of epoxy followed by a couple of coats of paint
would protect the wood just fine. Wood would be a lot cheaper than the aluminum too.