We’ve all been there—a painting project doesn’t use up all the paint you bought, and now it’s time to hammer the lid back on and take it to the garage or basement storage area. That paint will go bad in two to fifteen years. That’s such a big range, so how do you determine when it’ll be spent? Examine the type of paint and storage conditions to estimate shelf life. We’ll walk you through it.
Can Latex Paint Go Bad?
Latex-based paint can go bad, but it takes a while. You’ll probably be able to keep it for up to ten years, with a few caveats. The biggest factor influencing latex paint’s shelf life is if the can has ever been opened. If the paint is unused, you’ll get more life from it. An opened (and resealed) can of paint typically lasts for less time because of bacteria that can grow in the paint. Bacteria need certain conditions to grow, including darkness, moisture, and heat. All those conditions occur inside a closed paint can in your garage, shed, or basement. If you’re working with a modern, low-VOC or zero-VOC latex paint, it’s more likely to be ruined after a few years by bacteria growth.
You might be wondering why bacteria in paint matters: It’s not like bacteria on food, right? Although the bacteria that grow in paints aren’t going to be ingested, they break down the compounds in your paint, making it less adherent and leading to streaks and peeling.
Related Topic: What Are the Different Types of House Paint?
Can Oil-Based Paint Go Bad?
Oil-based paints can go bad, but it will take more than a decade. In fact, an unopened oil-based paint can last up to 15 years, which is five years longer than most latex paint. Unlike modern latex paints, oil-based paints have high VOC counts, which helps preserve the paint for longer. However, this also makes the paint more toxic to people overall, so be sure to paint safely.
Can Paint Primer Go Bad?
Primer can go bad just like regular paint, and it has a much shorter shelf life. Most primers have a storage life of two to three years, considerably less time than a paint can.
How to Tell if Paint Has Gone Bad
Regardless of the base type, there are a few key signs that your paint or primer has gone bad:
Odor. Just like rotten food in your refrigerator, there’s usually a harsh smell that accompanies an old can of paint that has gone bad.
Physical changes. You might notice the consistency of your paint has changed. There may be a “skin” on the surface or lumps that won’t stir out. If either of these is present, your paint has most likely expired.
Separated solutions. If your paint has separated into semi-transparent and opaque liquids, try stirring it to see if it comes back together. Wait a few minutes. If your paint reseparates quickly, you’ll know it’s no longer good to use because the solvent and pigment won’t work together to properly stick to the wall.
Where Can I Dispose of Old Paint?
Because paint is made of solvents and compounds that are potentially harmful, you shouldn’t just throw your old paint in the trash can. Many regional governments have programs set up to help people dispose of their old paint. And if your paint hasn’t expired yet, you can donate it to building charities.
Related Topic: How to Dispose of Leftover Paint
How to Avoid Leftover Paint
Unless you plan to do multiple projects in succession, you’ll probably end up with leftover paint at some point. To avoid the hassle of storing unused paint, call the local professionals at Five Star Painting. We can handle painting projects, both inside and out. We do a thorough cleanup when the job is complete, so you don’t have to worry about where you’re going to put sall those can of leftover paint. To get started on your paint project, schedule an appointment online or call (888) 261-3633 today.