When the cabin top comes out of the fiberglas mold, it needs to be trimmed to fit the project. The door opening as well as the doors need to be trimmed to fit each other. Invariably when the door opening is trimmed to the scribe lines Vans leaves on the mold, the match to the door is not perfect. Depending on the seal you place around the opening, the 'lip' needs to be formed. I used West Epoxy system. I used 105 resin and 205 fast hardener so I could apply to layers a day. Some understanding of terms and definitions will help. You need to thicken the epoxy so it will stand in place and not sag during cure. 406 filler (or cabosil as some call it) will thicken the epoxy mixture, but it is more difficult to sand. Once you have a very basic buildup, you sand it to the height or width you need and see gaps are still present. These gaps can be filled (this is called fairing) with epoxy and 407 filler (or microballoons as some call it). This 'fairs out' surfaces, ie fills in gaps and is easier to sand. Take your time with each step. No need to rush and taking your time pays off. Tongue depressors and popsickle sticks make good applicators as does a 1 inch flexible putty knife. In fitting the door to the cabin topI found if I place duct tape on the mating surface of the door and waxed that duct tape with car wax (all this to prevent the epoxy from sticking to the door), then latched closed the door, I could push thickened epoxy into the gap between the door and door frame. Once cured, I could open the door (the epoxy did not stick to the waxed duct tape) and the rough build up of epoxy/thickener mixture stayed in place. Then I go through the process of smoothing and fairing the buildup.
