Need to put good clear coat on acrylic paint.?

I just painted my paintball equipment with acrylic crafts paint but I need to put something on it that is clear and will make it not scratch easily. Last time i tried to clear coat something the clear coat stuff made the paint i put it on come off and worked just like paint remover. I need to know what type of spray on clear coat will be the best and not mess up the paint..





I want something under 20$Need to put good clear coat on acrylic paint.?
clear gesso paintNeed to put good clear coat on acrylic paint.?
Non-yellowing polyurethane...available at any home improvement store.