How Long Can You Keep Paint Before It Goes Bad?

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 us today.

This article is intended for general informational purposes only and may not be applicable to every situation. You are responsible for determining the proper course of action for your home and property. Five Star Painting is not responsible for any damages that occur as a result of this blog content or your actions. For the most accurate guidance, contact the Five Star Painting location nearest you for a comprehensive, on-site assessment.

FAQs About Paint Shelf Life

Our years of experience, attention to detail, and decades-long commitment to exceptional customer service set Five Star Painting apart from the competition. Continuing this high standard also includes using our knowledge and experience to answer your most frequently asked questions about paint shelf life.

Can I use old paint if I mix it well?

You can often use old paint if you mix it very well, but several factors determine its usability. The general paint shelf life for unopened latex paint is around 10 years, and oil-based paint can last up to 15 years. Once opened, this lifespan typically reduces to a couple of years, depending on storage conditions.

Before using old paint, check for signs of spoilage. A foul, sour, or moldy odor indicates the paint is no longer usable due to bacterial growth. Also, examine the consistency. Expired paint is often lumpy, thick, or has a skin that doesn't easily mix in. While separation of pigments and binders is common in older paint, thorough stirring should restore a smooth consistency.

When mixing old paint, ensure you do so thoroughly, preferably with a drill-powered mixer for several minutes, to re-incorporate all components. Straining the paint after mixing can help remove any dried clumps. However, if the paint shows signs of spoilage, it's best to dispose of it properly rather than risk a poor finish or lingering odors.

What’s the best way to store paint so it lasts longer?

Proper paint storage is important for extending its usability. Here's how to store paint effectively:

• Seal tightly: Ensure the lid is securely closed to prevent air from entering and causing the paint to dry out or form a skin. Gently tap around the edge of the lid with a rubber mallet for a tight seal.
• Store in a cool, dry place: Extreme temperatures can damage paint. Avoid storing paint in garages, attics, or basements that experience significant temperature fluctuations or humidity. A climate-controlled interior space is ideal
• Prevent freezing: Freezing temperatures can cause the water in latex paint to crystallize, leading to separation and a ruined consistency. Although less likely, oil-based paints are also susceptible to damage from freezing at extreme temperatures (around -4°F/-20°C)
• Invert the can: After sealing, invert the can briefly. This can create a tighter seal by allowing paint to fill the rim area, preventing air pockets. However, always store cans upright long-term to avoid leaks
• Clean the rim: Before sealing the lid, wipe away any excess paint from the rim. Dried paint on the rim can prevent a tight seal
• Use smaller containers (for partially used cans): If a can is mostly empty, consider transferring the remaining paint to a smaller, airtight container. This reduces the amount of air in contact with the paint

Can I revive thick or dried-out paint?

Reviving thick or dried-out paint is often possible, but success depends on how dry the paint is. For slightly thickened water-based paints, adding a small amount of water and stirring thoroughly can often restore the original consistency. Specialized paint thinners or conditioners designed for the specific type of paint (latex or oil-based) are also effective and less likely to compromise the paint's properties.

However, if the paint has formed a solid mass or hard skin that cannot be easily mixed back in, it's likely beyond saving. Similarly, if the paint separated in the can and vigorous stirring fails to re-incorporate the pigments and binders, resulting in a lumpy or inconsistent mixture, the paint is probably unusable.

For acrylic paints, flow improvers can sometimes help revive slightly dried paints. These additives can restore workability without significantly thinning the pigment. Avoid adding too much water, as this can dilute the color and binder, leading to poor adhesion and coverage. In cases of severe drying, proper disposal is the best course of action.