Yes, you can paint over non-paintable caulk. However, you will need first to treat it with a special primer.
Non-paintable caulk is based on silicone which makes it have water-repelling properties. The silicone base makes it difficult for paint to stick and stay on a surface even after drying.
Therefore, to prevent the peeling of paint on a non-paintable caulk, it is essential to first treat it with a special base primer before applying any paint.
How to Paint Non-Paintable Caulk
To paint over non-paintable, you will need the following things:
- Mineral spirits
- Pressure washer
- Oil-based primer
- 2-to-4-inch natural bristled paintbrush
- 2-to-4-inch nylon paintbrush
- Latex paint
- Acrylic latex paint
The following are the steps to follow if you have non-paintable silicone caulk that you want to paint over.
Step 1. Rinse the Non-Paintable Caulk
If you had left your non-paintable caulk unpainted for months, chances are it has accumulated dirt and dust. If the non-paintable caulk is located outdoor, you can clean it with a pressure washer.
For non-paintable caulk located indoors, use damp rags to remove the dirt and dust. After cleaning the caulk, leave it to dry for two to four hours. You can skip this step if you have just freshly applied a non-paintable caulk.
Step 2. Apply Alcohol to the Caulk
Before applying paint thinner or primer, directly apply denaturalized or rubbing alcohol to remove any sticky substances captured on the caulk.
Alcohol also makes the caulk’s surface rough; hence, it becomes easier to apply paint to the caulk and easier for the paint to stick to its surface.
Step 3. Apply Oil-Based Primer or Thinner
Using a 2-to-4-inch natural bristled paintbrush, coat the non-paintable caulk with an oil-based primer or thinner.
A natural bristled paintbrush is best suited for this application because it is engineered for oil finishes. Give the primer or thinner about two hours for it to dry.
The purpose of applying a primer first before painting is to give the paint grip so that it can strongly latch on the surface and avoid peeling off.
Depending on your paint or caulk thickness, you may need to apply primer coats several times. The primer thins out the paint for easier application.
Before purchasing any oil-based primer, check its label to ensure it can work with water-based topcoats. Most oil-based primers are not compatible with water-based latex paints.
Step 4. Clean the Brush Using Mineral Spirits
After using the paintbrush, wash it with mineral spirits. Since you used the paintbrush for applying an oil-based primer, avoid cleaning it with tap water; otherwise, you will damage the brush. Minerals spirits are very effective in the removal of oils.
Step 5. Paint Over the Primed Area
Using a nylon paintbrush, paint over the primed, non-paintable caulk with the paint of your choice. A nylon paintbrush is best suited for water-based finishes.
Apply the first coat, for example, latex paint, and wait for it to dry. You may need to apply another coat of paint because the primer can still be seen underneath the first paint coat.
For the second coat, you can use acrylic latex paint. However, be prepared for multiple coat applications if you can still see the primer underneath. Allow the final coat to dry for about two steps.
Step 6. Wash the Brush with Water
If satisfied with the appearance of the final paint coat, you can wash the brush. Nylon paintbrushes should be washed with water. Mineral spirits will damage the brush.
If you have been unlucky in getting the primer and paint to stick over the non-paintable silicone caulk, you still have one more option to try.
Add a Layer of Latex-Based Caulk on Top of the Non-Paintable Caulk
Here is how to go about it.
- Remove all the primer and paint you applied to expose the non-paintable caulk.
- Then apply the latex-based caulk. Latex-based caulk is easier to paint over with several types of paint.
- Even apply a thin layer of latex-based caulk across the entire surface of the silicone-based caulk.
- Leave the newly applied layer of caulk to dry thoroughly before you begin painting it.
Can You Paint Non-Paintable Caulk?
Fortunately, yes you can paint non-paintable caulk. However, you will need to first treat it with a special primer. Here is how to go about it.
- Rinse the Non-Paintable Caulk
- Apply Alcohol to the Caulk
- Clean the Brush Using Mineral Spirits
- Apply Oil-Based Primer or Thinner
- Clean the Brush Using Mineral Spirits
- Paint Over the Primed Area
- Wash the Brush with Water
If you are unlucky in getting the primer and paint to stick over the non-paintable silicone caulk, you can try adding a layer of latex-based caulk on top of the non-paintable caulk before painting over it.