questions about ramp plans

[antihero898]

my friends and i are building a 3.5 ft tall by 5 ft wide mini ramp and have finished the skeletons on both sides of the ramp. were going to continue with the surfacing tomorrow, and i was wondering if two layers of plywood is ohnestly worth the money compared to just one. were limited in terms of money, and we are trying to keep spending to the minimum. and in terms of the surface, what is the easiest was to put the plywood on using the warm water technique. in terms of the painting, what should we buy/ do in terms of painting plywood and/ or the massonite. were going to continue building tomorrow so a quick response would greatly be appreciated .

[antihero898]

update:

we have finished the surfacing of the plywood. we decided to say screw it and use two layers. what were still confused on is what we should exactly use, brand wise, type, ect, for the masonite to make it weatherproof. we are thinking of painting the masonite and then putting on the finishing, but were arent sure what type of polyurethane we should get. we did buy spray paint canisters for the art, and bought crystal clear semi gloss polyurethane finisher. on the back of the can, it said the polyurethane was for water based wood, painted and exteriors of the house. we dont want the ramp to be wayyyyy too slick, we just want it smooth. should we stick with semi gloss, or what do you suggest?