Another aspect of square tubing for the door frame is the face of the tubing is only perpendicular to one surface, inside or out. I decided that the tubing would be at a 90 deg angle to the inside of the door and the outside skin would be adjusted. The day of reckoning has come and I need to compensate on the outside skin. I decided to use JB weld as the filler material. So the epoxy wouldn’t stick to the door skin I left the plastic coating intact on the skin and brushed some mold release agent on the area where it would touch.
