your thoughts on this mad cap idea

can a thin plastic film be used to seal the air away from wet gelcoat for it to cure hard, if so could the sheet of plastic film be place over the roof of a boat which has just been rolled with 3 coats off gelcoat then if all the edges sealed with tape,if you could use a vacuum cleaner from under the roof say though the are vent to suck the air out ( like vacuum packed ) would this not leave a super smooth cured coating apart from some sanding still needed

 

You want either topcoat (waxed gelcoat) or high gloss additive (Duratec)

 

That only works for a completely flat roof. On all other shapes the plastic will get folds that ruin the gelcoat surface.

 

Forget about gell coat. just paint it. urethane or similar.

In your sun void climate epoxy may be OK.