Oil vs Water Hack. When painting over existing paint, it’s important to know whether the old paint is latex or oil by doing this simple test. Rub a cotton ball soaked in rubbing alcohol over the painted surface. If your cotton ball has paint on it, the surface is latex. If not, the surface is oil based paint. If it’s oil-based, you’ll need a coat of oil-based primer before starting. Or use a deglosser such as Krud Kutter. www.theidahopainter.com
