Painting Over Oil-Based Paint
Equipment / Tools
- High-quality paintbrush
- Fine 180-grit to 220-grit sandpaper
- Medium 100-grit to 150-grit sandpaper (optional)
- Putty knife or five-in-one tool
- Tack cloth
- Wood putty or wood filler
- TSP (trisodium phosphate)
- Paint primer, bonding
- Soft sponge (for TSP)
- Protective glasses
- Protective gloves
De-Gloss the Surface
With sandpaper, manually scuff down the surface of the oil-based paint layer for improved stickability. Aim for eliminating surface sheen or gloss; the goal isn’t to remove the paint, just scuff up the surface so new primer and paint can adhere well. If fine-grit sandpaper isn’t working well, switch to gentle scuffing with medium-grit sandpaper.
Pry off any loose paint from the surface with a five-in-one tool or putty knife. Just remove areas of failing paint. Solid paint can remain.
Fill in Small Gaps and Holes
Fill small gaps and holes with wood putty or wood filler. Let the filler dry completely, then lightly sand the filled areas with a fine-grit sandpaper.
Clean With a Tack Cloth
After the surface is completely dry, gently use a tack cloth to wipe down the surface to catch dust, dirt, or sandpaper granules.
Deep Clean the Surface
If the surface is exceptionally dirty and greasy even after using a tack cloth, your best bet is to use TSP to do a deep cleaning before priming.
Mix 1/4 cup to 1/2 cup (for extra dirty surfaces) TSP with a gallon of hot water. Use a sponge that’s damp with the TSP solution to wash the surfaces. Wash surfaces from the bottom up to reduce streaking.
After cleaning with TSP, sponge the surface with fresh water to rinse (unless you have chosen a no-rinse TSP formula). Let the surface thoroughly air-dry.
Prime the Surface
With the surface completely dry and clean of dirt, you can now prime it. This is essential as it provides the latex paint with a porous surface to help it stick. Brush the primer onto the surface. Brush one coat but preferably two coats of primer on the surface. Let it dry thoroughly.
Paint the Surface
After the primer is dry, you’re ready to paint. Paint as you normally would, using two coats if necessary. Let the paint dry for at least two hours between applications.