We decided to paint the clear-coated trim in family room, on fireplace, and half wall dividing family room and kitchen in a semi-gloss. We started with the half wall by priming it and then painting. The moulding took to the primer and paint well using a bristle brush...no problem. The flat piece of wood on top did not do so well. I wanted to use a sponge brush to avoid lines from a regular brush but the paint store steered us away. The brush left brushstrokes when applying primer. We sanded it down. Then back to the store we went to ask about correcting this. We were given a thick roller to use. I still thought sponge would be better but we were told sponge doesn't hold enough paint to use on wood. The second attempt at primer went on thick and rippled. We sanded it enough to just smooth out leaving the wood primed and tried to roll the paint hoping the primer was the problem. The paint did the same. It looks thick, rippled and has more shine than the trim below it. I don't know what happened and I'm afraid the same thing will happen to the fireplace so now I'm contemplating sanding the paint off the half wall trim and clear-coating the wood again to spare myself the grief. What went wrong?