Originally Posted by johnwohl
What I decided to do after reading a few threads was to sand the foam well with 400 grit, use denatured alcohol to remove the dust and any remaining release agent, and use minwax water based polycrylic as a base coat for spray. the recommended number of coats seems to be at least 3 so I'll do like 5 with wet sanding in between as the polycrylic weight is next to nothing when it dries. with the polycrylic acting as somewhat of a shell, the spray paint should never even touch the foam. people seem to have had good results with this method but time will tell. it will take me another day or two to get everything with a good 5 coats.
Polycrylic? Ummm....I'd strongly suggest you try it on some scrap material first - even if not foam -- more for how well it accepts sanding or any further 'disturbance' after drying. I had far less than desirable results when I tried it for 'planking' my Blaze's control surfaces. It's like laying down layers of soft vinyl rubbery film, & when you rub it later (as in sanding before the next coat) it 'pills' & the particles 'snowball' as you continue rubbing, peeling much of it away.
If I had it to do again, it'd be water-base polyurethane