We frequently get questions about painting over oil base paint with a latex base product. There is a common belief that one cannot paint over oil base paint with latex paint. This is not true. With proper preparation, which frequently includes the use of a primer like “Gripper”TM from Glidden, you can paint over just about anything.
Still, lots of people want to know how to tell if they have oil or latex base paint on the wall. A simple way to tell is to take denatured alcohol and apply it to a small inconspicuous spot. If the paint dissolves it is latex. If it is unaffected by the alcohol it is an oil base product. That’s easy enough.
Here are a couple other things to remember:
· When you want a nice hard finish that will resist dents and dings an oil base product or enamel is best.
· If you are painting outside or somewhere that will be subject to significant temperature variation use a latex base product. These products are much more “flexible” once they cure and they handle the expansion and contraction associated with temperature change much better than an oil product which cures to a hard rigid finish.
· If you are painting over an oil base product or a latex product that has a gloss sheen you should sand the surface prior to applying primer. This will “knock” the gloss off and improve the adhesion of the paint.
· If you are going over an oil product that is on the outside of a home with a latex product we recommend priming. In addition you should make sure that any area where the oil paint has cracked or peeled is repaired by sanding and priming.
· Remember to sand the edges of spots that have peeled and fill them back in with an exterior spackle so the rough edges do not “telegraph” through the new coat of paint.