How to Tell if Paint Is Oil

When you're going to paint over a wall, you need to know if you're painting over oil based or latex paint. If you're painting over oil based paint, you need an oil based primer before applying a new coat of latex. Fortunately, there's an easy test that does not involve sniffing or tasting paint chips.

Difficulty: Easy

Instructions

Things You'll Need:

• soapy water
• washrag
• cotton ball
• denatured alcohol

1. Wash the wall well with mild detergent in an inconspicuous spot. Rinse it with clean water, then dry with a towel. You don't want to get a false result with a dirty wall.

2. Soak cotton ball in denatured alcohol. Rubbing alcohol works fine.

3. Rub the cotton ball over clean spot.

4. 
   Latex paint on cotton ball

   If you see paint on the cotton ball, it's latex. You can paint over it with a latex paint.

5. If there's no paint on the cotton ball, it's oil based. You'll need to use an oil-based primer to cover the paint. You can then follow with an oil based or latex paint.