I'm having my softtail repainted hears his responce to the "JB weldtrick" Hi Ron,
Paint savers which use glue, like JB weld often cause more problems then they solve.
The real trick is to use the correct primer to the steel for the job in the first place. This eludes the body-shop trained tech as body shops go for the cheapest material much like any contractor does when building. Some paint savers which use a rubber seal do work, but most which rely on silicone or epoxy fail in just a couple of years. Honda and Yamaha often use the epoxy primer in local areas, meaning just around the points where fuel enters or leaves the tank. In this case where your tank is already painted, this is how your tank will be repaired.
Motorcycle paint work is a step past what body shops do, unless they are trained to work in the higher end systems and versed in urethane paints. The correct curing of the paint is really the problem most body shops seem to miss. The best result is to be sure any rubber seal hits steel, and that any fuel tank is epoxy primed. This limits the fuel to a very small amount of primer to attack, where using glues expands the porous area, allowing fuel to sit and lift the paint.
The other issue is the clear itself, and the chemistry used. We have moved toward using clear products which use little or no reducer. This provides a very hard quick cure. More often then not, we also use bonder clear before the urethane clear to ensure lifting cannot happen. Most paint manufactures insist on high solid clears, but they tend to have trouble with becoming hard as the reducer becomes trapped, resulting in a soft clear. The idea is to provide a thick clear, which can be polished out to limit surface irregularities. We have trended away from this and rather limit clear to two coats at a time, wet-sand and re-clear if the artwork is an issue. This ensures the reducer escapes properly, and ends up being able to resist gasoline spill and vapor problems. No clear is impervious to gasoline on a long term basis, and it is important to be sure the tank vents properly. Many aftermarket tanks (like choppers often have) rely completely on the fuel cap vent. This does cause problems. The recessed bung and flush cap system is one that is prone to issues of fuel vapor. There is no place to hide any kind of JB weld as the leading edge of the paint ends exactly where the fuel bung is set. After 25 years of working with the problems I have seen all kinds of attempts to avoid using the correct epoxy primer products, correct sand blasting and masking needed. None of them work. Our product research aims at a minimum of ten years and our warranty is for one full year.
We just do it right, and sleep much better. You will too.
Thanks,
John
