Red Max Pro is/was a 3 part system with a primer, finish, and remover. I assume ZEP has somethilng similar. No question 12% ammonia from the hardware (most will have to order it) is strong enuf to cut Red Max. Best wear gloves as considerable exposure to ammonia will dry and burn your hands, unless of course you didn't wear them while applying the wax, in which case you might want to use the ammonia to remove your shiny manicure. As to the relative insolubility (w/ resulting durability) of the finish (including the runs), the floor waxes wouldn't be of much more interest than a buffing wax if they washed off in the first rainstorm. As to the problem of the relative porosity of gelcoat (which can be seen on many an old trailer with a healthy crop of algae and moss), the ability of the liquid waxes to flat out and seal is also a positive benefit imo. The necessity of deep cleaning and light
abrasion of the surface prior to application (Barkeeper's Friend. Simple Green, Tri-sodium phosphate) has been emphasized by many who have gone this route and can't be over-emphasized. I believe many older trailers exhibit two quite different qualities of deterioration of the surface: very chalky and porous gelcoat on the roof along with vertical areas lower down which retain a less degraded surface quality (smooth to the touch, retaining some reflectivity of light). Removal of the chalked and presumably very porous gelcoat (the result is the rinse water running white into the storm sewer) as well as a light
, uniform cutdown of areas which retain some surface cohesion and integrity are both a vital part of prep as they would also be for a sprayed paint
finish. The removal of loose material and the slight "etching" of better preserved areas is not the end of the work. Obviously the removal of surface contaminants (buffing waxes which may remain in protected areas) is vital. And the removal or depigmentation of mineral stains with bleach or the weapon of your choice also contributes to a uniform appearance thru the transparent wax. Clean, clean and clean again.
The possible present and future negatives contingent on this treatment have been made clear by other posters to the thread. The view that this is a "last resort" for an inexpensive surface restoration of older trailers has been mentioned many times by the original poster and subsequently by many to whom the treatment appears to look good, reduce maintenance, and evidence the promise of at least medium term durability exposed to the elements. Nothing is forever as those with expensive repaints will also discover in the fullness of time. Whatever paths your restoration efforts take you down, may you have immediate success and enduring satisfaction.