If you look at how your fiber glass front or rear cap is made, Gel coat is applied to the mold first then Fiber glass reinforcement during the manufacturing process. The gel coat is pure resin the FG reinforcement is FG and resin. Clear coat is sprayed on after the MH is assembled and is to protect the paint and make it shine. Not all MH's have clear coat. Some older ones like mine only have gel coat on the front and rear caps not on the flat sides. If you can see a random FG pattern on the outside there is no gel coat. If it is completely sooth it is gel coated. The products mentioned above are safe to use on your exterior.