Why Paint Bubbling Happens and How to Fix It
It's happened before—a fabulous paint color on the walls which you thought would brighten up your space instead causes heartbreak when it bubbles up hours, days, or even months after application. There are several reasons why this may have occurred. Identify the culprit and fix the mistake to reap the rewards of that new paint upgrade.
Dirty Paint Surface
It’s always part of the prep before painting, but if you opted to skip cleaning the surface of dirt or grime, this can keep the paint from adhering properly. Simply painting over these loose particles will cover it for a moment, and eventually create a blister around the soiled surface as the paint dries and shrinks.
The Fix: Scrape and patch the area of blistering, then clean with a damp, soapy sponge, drying with a rag afterward. Allow to dry completely, then apply primer and paint to areas that were patched.
Don't Skip the Primer
Priming before painting may seem like another extraneous step, but we assure you, it’s necessary. Especially when painting directly over a porous surface like drywall, or over another painted surface. Omitting the primer gives the base coat a much thinner binder film since more of it has been absorbed into the wall's surface. Areas where the second coat doesn’t stick to the base coat will then begin to blister and flake off.
The Fix: Remove bubbles by scraping and patching. Clean the surface and add either a latex or oil-based primer based on the type of paint you’ll be using. The primer seals the pores in the material, giving you a thicker base coat for paint to adhere to. Just be sure to allow primer to dry before adding the next layer of paint.
Oil Based Coat on Top of Latex Paint
Generally, oil-based paints are extremely durable and can be scrubbed without damaging the paint job. They make sense in high moisture rooms like the kitchen and bathroom. When refreshing your scene with some new paint, don’t layer an oil-based coat on top of latex. It won’t bind securely and will blister and bubble.
The Fix: Use a putty knife to scrape off the blisters. Rinse the knife, wipe clean the surface, and fill holes or cracks with a patching compound. Let it dry and set before sanding it down with fine-grit sandpaper. Prime and paint.
Moisture on the Surface or in the Air
Humidity really makes a difference when painting, and so do plumbing problems that cause leaks or condensation to form on the walls. The excess moisture from inadequate bathroom ventilation or improperly vented kitchen hood can create water-filled bubbles in the paint, and can be common when repainting kitchens or bathrooms where there may not be good ventilation or where moisture tends to accumulate.
The Fix: Find the source of the moisture and take care of it before beginning the fixing process. Any leaks or loose plumbing fixtures will only add to your frustration when you have to continue doing it over and over again. Once the problem is fixed, scrape, patch, clean, and dry the surfaces you want to paint. Keep the humidity low while the paint cures—so if it comes down to it, shower at a friend’s house or head out for dinner rather than cooking at home.
Too Hot to Handle
Surfaces and surroundings that are too hot won't be a good environment for painting. The heat may lead to uneven drying caused by drying too quickly.
The Fix: Remove bubbles with a scraper, then patch, clean and prime. Before applying the next layer of paint, get a temperature reading and ensure it’s between the recommended ratings as specified by the paint manufacturer—usually between 50 and 85 degrees Fahrenheit. Close blinds and doors where sunlight can enter the room to keep temperatures from rising and causing bubbling to happen again.
Wrong Roller Cover
A short nap length on a roller won’t suffice when painting a highly textured wall. This can only lead to uneven coverage and blistering. Use the right length on your roller to provide the best coverage.
The Fix: Repair with the scrape, patch, prime, and sand method. Affix a paint roller of the right length to properly prime the surface, and paint afterward, allowing each layer to dry fully before applying the next coat.
Proper paint prep can save you time, money, and oodles of frustration that often accompany a painting project. Do yourself a favor and prepare for the job before embarking on your next painting journey.