jeremysam:
From our experience if you are looking for a rollon the best bet is to get a water based clearcoat from a hardware store., you might be able to get away with a polyeurethane clear coat as well. Look for ones that claim non-yellowing as well as UV coating. If your local hardware store or mega store like Home Depot doesn't have one (they should), then try contractor paint store like Sherwin Williams who have a much wiser selection of specialized paints than your big-box retailer or hardware store will have.
is there a roll on clear coat product to use to protect a spray wall and that does not yellow from the sun?