How do I bend aluminum roof trim?

I have a Le Baron roof kit for my 33 coupe.
As you are probably aware it comes with straight lengths of aluminum strip with the channel for the rubber. This has to be bent to the shape of the roof opening
I have tried carefully bending this on a flat surface but it wants to pucker on the inside of the curve.
Is there a trick to this?
Do I need to apply heat?
Anybody on here done it successfully.
Thanks in advance

Chris
PS if anyone wants to part with an original set of roof tack strips for a 33 5W let me know.

 

melt some lead in that area of the bend. after bending heat it up to remove. mike

 

I created an aluminum pattern of the front and back radii, 1/8 thick. Lay the pieces on straight side, clamp it down and make reference marks to remove and replace after checking. Hand roll it around radius CAREFULLY a little at a time. If it starts to kink, place scrap in channel and try a little further. Your scrap rate is high, but it simple and cheap, and can be done in garage. I ended buying twice the channel I needed. A small amount of hammer dolly work may be needed to make it nice. Remeber it don't have to be perfect, no one will notice.

 

Try putting some wire in the channel before bending which wouldn't allow the ali to pucker.make a wooden buck to clamp to your bench and bend slowly around it. Good luck,steady,steady.