Roof rail help

[speedjohnston]

Has anyone made roof rails? I know they are usually 3/4 high, 1/2 base L shaped .050 aluminum and usually riveted to the roof, but it's more the shaping i'm concerned about. Any tips and tricks? Any other ideas for fastening to the roof so the roof stays waterproof but they are removeable and stay on the car at high speed? Do they tend to distort when shaping to the roof? It's something I may attempt over the winter time.
Thanks for any ideas.