Tried painting mine satin black and to be honest with you I did not like the way it turned out so I ended up getting a new liner . I tried cleaning it before I started and the liner started to get some fuzzys on it (like lint on a sweater) so I stopped and just painted it .I cleaned it off the best I could , shop vac and wiped down a few spots with a general purpose cleaner and let it dry completely ..The liner itself was not in bad shape just showing some age and I wanted to freshen it up prior to adding a set of Solstice letters from ASAP Graphics . Needless to say I used spray cans Rustoleum with primer(the stuff you can use on any surface plastic ,wood ,metal) and the liner just soaked the paint up 6 cans and counting . I let it dry completely between coats and for some reason I had areas that have a shiny sheen to them .I have seen people who have painted their liners with good results and I wonder if they were new ? If I had to do it all over again I would take it to my painter and get his opinion maybe I needed a sealer ? Still have the old liner in the barn and I'm going to respray it this spring and see what happens .
My painter has done several. What works best for him is to use an epoxy based sealer to fill the poured in the fire blanket before applying primer and then paint. The sealer leaves the blanket with a hard, smooth surface that takes paint like metal and looks very nice.
Good advice I should have tried that but read a couple of articles that said the paint/primer would act like a sealer after a few coats .Still can't figure out the shiny spots but I'll try a repaint in the spring