Brush onto a lightly keyed surface is fine. You will in most cases be fine with applying direct to paint in terms of adhesion.  I would spray up a piece of scrap wood and test the resin on it to make sure the epoxy doesn't damage the paint.  Most epoxies are fine with paint as they have a very low amount of solvents in and usually its solvents that react with paints.  Apply it thinly to the sides and build it up in layers.  It is likely you will still get some run off, but once fully cured you can sand and polish to remove any blemishes and get a good even finish.

Warren Penalver
Easy Composites / Carbon Mods - Technical Support Assistant

Here's the piece to be coated.

hi all,