How can I know if an applied paint is solvent or water based?
If the old painting flakes, take a part of this paint and place the edges of the piece between your thumb and index finger; apply pressure on the edges of the piece. If the piece is flexible and bends easily, it is probable that the painting is latex (base water). If the piece is hard and brittle, it is probable that the paint is solvent base. Another method is to damp with denatured alcohol a piece of cotton and to rub the surface of the paint. If the paint becomes soft or rub offs, it is probable that the paint is water base. This test with alcohol generally does not affect solvent base paints.
