Yellowing Paintwork? How to Fix and Prevent Discoloration - Bob Vila

2023-01-03 11:20:40 By : Mr. Steven Zhang

By Manasa Reddigari and Bob Vila | Updated Dec 7, 2020 1:50 PM

We may earn revenue from the products available on this page and participate in affiliate programs. Curing Agent For Waterborne Coatings

Yellowing Paintwork? How to Fix and Prevent Discoloration - Bob Vila

Q: The white oil-based paint coat on my office cabinet has yellowed in recent months. Is it possible to reverse the yellowing, and if so, how?

A: If that once-white cabinet, door, or wall now looks yellow, your eyes don’t deceive you! For all the benefits of oil-based paint, including dent and scuff resistance, it has a notable drawback: It can turn yellow with time, an effect that’s particularly unsightly on white or off-white surfaces.

Whether or not you can reverse the discoloration or must tackle the tinge another way depends on the cause. Read on to identify what’s behind the yellowed paint in your home and learn how to restore its original color.

RELATED: 12 Easy Fixes for a Botched Paint Job

As oil-based paint coats dry, unwanted color-producing molecules known as chromophores also form in the paint. These chromophores break down when paintwork is regularly exposed to light, either natural or artificial. When the paint doesn’t get much light, chromophores remain in the paint coat and cast a light to dark yellow tint across the surface. If your paintwork is located in a dimly lit area—such as a cabinet interior or behind a tall piece of furniture—a lack of light is the likely cause of the yellowing.

Fortunately, the effects of chromophores are reversible, as exposing yellowing paintwork to light should break down the problematic molecules in the paint and gradually restore its original color. To shed more light on the paintwork, move any furniture blocking it and draw open the curtains of a nearby window (if the room has one) during daylight hours. If the room lacks windows or natural light doesn’t reach all of its corners, shine an artificial light source such as a table lamp or a wall sconce on the paintwork during waking hours. The paintwork may begin to lighten in as little as one day, but you’ll need to continue to expose it to light over time to minimize future yellowing caused by oxidation (see below).

Moisture from water, cooking grease, or cigarette smoke can also impart a yellow tinge to paintwork. If you suspect that a leak is behind a water stain, suss out the source of the leak and repair it. Then, gently sand down the stain with medium-grade sandpaper and use a paintbrush to cover the spot with stain-blocking primer in the same shade as the painted surface. To remove cooking grease, fumes, or cigarette smoke, don gloves and goggles, dilute a quarter cup of trisodium phosphate in a gallon of water, then dip a sponge in the solution and wipe down the stain to remove it. Dry the area with a clean rag.

If the above techniques don’t reverse the yellowing, the cause is likely oxidation, the natural curing process for oil-based paints. The alkyd (synthetic resins) or plant-based oil react with oxygen in the air to dry and harden the paint, but they may also turn it yellow as the coat ages. While oxidation-induced yellowing is irreversible, you can cover it up by priming and painting over the oil-based paint with water-based options that dry through evaporation rather than oxidation and won’t yellow over time. Just keep this in mind for vibrancy: Water-based paints labeled “all-acrylic” or “100 percent acrylic,” which contain high-quality acrylic resins, tend to produce a more colorfast finish than regular latex paint, which usually contains vinyl resins or a combination of vinyl and acrylic resins.

As with other paint problems, prevention is the best solution when it comes to yellowing paintwork. If you’re set on using oil-based paint for your next paint project, use these application tips to minimize future yellowing:

Copyright © 2023 Acton Media Inc. All rights reserved.

Yellowing Paintwork? How to Fix and Prevent Discoloration - Bob Vila

Waterborne Polyurethane Curing Agent Articles may contain affiliate links which enable us to share in the revenue of any purchases made.