Varnish Makers and Painters Naphtha can be used in place of Paint Thinner for oil-based paint, varnish and enamel when a faster drying time is desired. It can also be used when spraying to help prevent runs. Not intended for sale or use in California. Our Kelan-Strip solvents and thinners are mixed into wet paint, varnish, stain and other finishes to weaken consistency and thin them out. They're also great for clean up. Kelan-Strip products are like elbow grease in a can. They're formulated for professional use to strip years of old paint, clean up heavy-duty spills and give homes a second chance.