How to Paint Non-Paintable Caulk

Acrylic caulk is appropriate for painted surfaces, because it is well suited for adhesion. Unfortunately, inexperienced do-it-yourselfers often choose non-paintable caulk instead. Non-paintable caulk is made of clear silicone. If you apply paint directly over untreated silicone caulk, peeling will inevitably occur. Fortunately, you can paint non-paintable silicone caulk as long as you treat it with a special base primer. Employ the right preparation procedure, or you will have little chance at paint adhesion.

Things You'll Need

  • Pressure washer

  • Rags

  • Oil-based primer

  • 2- to 4-inch natural-bristled paintbrush

  • Mineral spirits

  • Latex paint

  • 2- to 4-inch nylon paintbrush

  • Acrylic latex paint

Step 1

Rinse exterior non-paintable caulk with a pressure washer. Use damp rags if the silicone caulk is located indoors. Allow at least two to four hours of dry time.

Step 2

Purchase an oil-based primer that is compatible with latex topcoats. Coat the non-paintable caulk with the oil-based primer. Apply the primer, using a paintbrush that has natural bristles and is engineered for use with oil finishes. Wait two hours for the primed caulk to dry.

Step 3

Wash the brush with mineral spirits. Do not use tap water, as this will damage the brush.

Step 4

Coat the primed non-paintable caulk with latex paint, using a nylon paintbrush engineered for water-based finishes. Finish exterior non-paintable caulk with acrylic latex paint. Wait two hours for the finished caulk to dry.

Step 5

Wash the brush with water. Do not use mineral spirits, as this will damage the brush.

Tip

Kilz manufactures an oil-based primer that is compatible with latex topcoats.

Warning

Most oil primers will reject water-based latex paint. Examine the label to ensure that the oil primer you select will work with water-based topcoats.

Do not paint over unprimed non-paintable caulk, or adhesion problems will result.