For high-impact areas like trim work, doors, and cabinets, oil-based paint used to be the standard in the interior painting industry. Oil-based paint self-levels as it dries, producing a flat, perfect surface. It is strong and long-lasting. But, oil-based paint isn’t flawless.
Oil-based paint releases a variety of VOCs (volatile organic compounds) that are bad for the environment when it dries. Because mineral spirits or paint thinner must be used to clean up instead of water, the paint is frequently sloppy and stinky. The biggest problem with oil-based paint is that it’s getting harder and harder to find.
As a result, if you have a surface that has previously been coated with oil-based paint, you might not simply be able to paint over it with water-based paint; you might also be limited in your options. The good news is that water-based acrylic-latex paint and other oil-based paints may be painted over oil-based paint with the proper preparation.
Applying Oil-Based Paint On Top of Oil-Based
Paint either sort of oil-based paint that has dried. It is possible to repaint with either alkyd- or natural oil-based paint once oil-based paint (either an alkyd or natural oil formula) has fully dried. It can take seven to thirty days for oil-based paint to set to the point where it can be wiped or washed without damaging the surface before it is deemed totally cured.
Be careful not to apply alkyd over natural oil-based paint that hasn’t fully dried. Only use natural oil-based paint when repainting natural oil-based paint that hasn’t yet dried. Using alkyd paint would result in the natural oil-based layer beneath continuing to harden after the alkyd coat has dried, which would cause the top coat to break.
On the other hand, uncured alkyd paint may be securely coated with either alkyd or organic paint without worrying about the top coat splitting.
Applying Oil-Based Paint Over Water-Based
When applying water-based paint over oil-based paint, degloss the surface. Remove as much shine from the surface as you can before repainting since water-based paint doesn’t adhere well to the glossy surface of oil-based paint. Using fine-grit sandpaper, go over the whole surface in one motion (180- to 220-grit). You just want to sand the surface until it is level and no longer slippery, not all of the paint. After that, use a tack cloth to remove any remaining sanding dust from the surface.
When applying paint, thoroughly clean the area with TSP. Following sanding, clean off any dirt and grime from the oil-painted surface since they might hinder the application of water-based paint. Pour one gallon of warm water and a quarter cup of trisodium phosphate (TSP) into a big bucket while wearing gloves and safety glasses to prevent splash damage.
To remove dirt, dust, and grime from the sanded surface, dip a soft sponge into the TSP solution, softly wring it out, and then wipe it off. Using a sponge saturated in new water, give the cleansed surface a second pass before allowing it to air-dry.
When applying water-based paint over oil-based paint, prime first. Use bonding primer over the previous oil-based coat for the best paint adhesion to avoid peeling and chipping during the drying and curing process. This primer is designed to attach to glossy and other difficult-to-paint surfaces.
An oil- or water-based bonding primer should be applied in one to two coats and dried in accordance with the product’s instructions. When the old paint color, stains, and other surface flaws are hidden, the surface has been sufficiently primed.
Oil-based paint should be covered with at least two coats of water-based paint. Apply at least two coats of a premium water-based latex or acrylic paint over the primed surface using a brush, roller, or paint sprayer, providing adequate drying time between applications and following the product’s instructions. Use paint designated for “interior” usage for painting interior elements (such as kitchen cabinetry).
When painting external elements, “interior/exterior” paints are preferable since they resist decay and harsh weather better (e.g., the front door). Use a complimentary hue and a semi-gloss finish when painting molding or other trim to draw attention to the details.