Yeah, it's too thick and that's why the resin is pitted... when painting a board only use Acrylic (Tempra is no good) and it's best to spray light coats but brushing can work too, just keep it thin.Another thing in the future is to screen the board down to close all the holes in the foam for a nice surface... An option for colorwork other than paint is to do a "foam stain" with pigmented resin. Just squeegee it on the foam and let cure. Then you can do a clear glass job over it. Looks like paint but different application.