When I put clear polyurethane over white paint, it turned yellow as it was being put on. What can I do?
John Brock: Choose a waterbased polyurethane instead. Any waterbased polyurethane will go on clear and will not yellow over time. Oil-based finishes start yellow and get more amber as they age.
Michael Dresdner: That’s good advice for the future. For now, all you can do is remove the finish and start over, or simply paint over the polyurethane with primer and white paint. For what it is worth, there is rarely any reason to go over paint with clear polyurethane as there are plenty of white paints that are adequately durable on their own.