I just finished building a table from an old barn door. This one will be used outside on a open deck. I put 2 coats of primer and 3 coats of exterior latex paint on it. Question, is there anything I can put on the paint to help it hold up to the weather or is it best just to leave it with just the painted surface? It will be stored inside during the winter months. I'm trying to keep it as a soft glow finish. Thanks.