After every painting job, some paint remains once the project is completed, and we tend to cover the lid and keep it away. But have you ever wondered, "How long does paint last in a can?" Well, it's not like the paint will go bad in just a few days. However, knowing when the paint is in usable condition helps ensure that it is used as early as possible to avoid paint wastage.
The shelf life of paint differs and depends on several factors, such as the type of paint, storage conditions, the weather conditions of the region, and more. So, if you're wondering when you can use the leftover paint before it goes bad, this blog answers your question in detail and helps you make better decisions.
Can Paint Go Bad?
Eventually, all paint goes bad within 5-6 years of opening the can, even if properly stored and sealed. An unsealed latex or acrylic paint has a lifespan of up to 10 years. On the other hand, oil-based or alkyd-based paint can last up to 15 years. Moreover, chalk paint and milk paint last up to 1-3 years and 1-2 weeks after they're mixed, respectively.
Storage and weather temperatures adversely affect the paint cans, making them go bad before expiration.
An opened and resealed can of paint lasts less time because there are chances of bacteria growing in it. As you know, bacteria need moisture, darkness, and heat to grow. This makes a can of paint hidden in your garage the best place for them to not only live but thrive. These bacteria break down the paint compound, making it less effective, less adherent, and reducing the quality of the paint.
How to Tell if the Paint is Not Usable?
No matter what base your paint has - there are always certain signs that can indicate if the paint has gone bad. These are :
Foul Odor
While you may love the smell of a fresh paint can, bad paint's odor is unbearable. If the paint has expired, it will have a pungent, sour, or rancid smell. A bad can of paint can also smell like rotten eggs.
Changes in Consistency
If you look at the can of paint stored in your basement or garage for too long, you might notice a slight or significant change in the consistency. Old acrylic paint may have a thick and smooth consistency, like cottage cheese. You may also find a fine film of paint on the top layer, in addition to the lumps that are just not "stirrable."
Mold and Mildew Growth
It is advisable to close the can to ensure the paint doesn't spill. This prevents mold and mildew growth. When mold and mildew grow inside the can, they can spread along the inside walls and across the top of the paint liquid. So, if you see a greenish substance in your paint can, it's time to discard it!
How to Dispose of Expired Paint?
Never use expired paint paints. Instead, use a proper disposal method to get rid of them - depending on the paint type. Here are some of the disposal methods -
Oil-Based Paint Disposal
Oil and alkyd-based paints are hazardous waste. If disposed of improperly, they could contaminate drinking water and soil. Disposing of expired paint anywhere is harmful to the environment. It is also advisable to avoid flushing the paint down the toilet!
US law prohibits tossing old paint in the garbage or landfills. Instead, it is advisable to drop it off at a designated location. Some paint stores in the USA have developed a paint recycling program to ensure that expired paint is not being disposed of in unwanted places.
Latex Paint Disposal
Most modern latex paint formulations have water or acrylic as a base, which is better for the environment. Throwing only the solidified latex paint in the landfill or garage is advisable. Even if there is a small amount of latex paint, open the lid and let it dry until it becomes solid.
Pour the remaining paint into a newspaper and let it dry. Once dried, throw it into the garbage for pickup. If there is a lot of latex paint, add cat litter to it, stir it, and let it dry. Also, adding a paint hardener (up to ⅔ of the gallon) works wonders. You can easily find one at home improvement stores.
Chalk Paint
The best way to dispose of chalk paint is to take it to the paint recycling center in your area. You can solidify it and throw it away in the regular trash. Moreover, you can check and donate it to your local art group or community, who may use it further.
| Notes | You can drop off the expired paint at a designated disposal facility in your city or county. |
How to Store Paint Properly So That It Lasts Longer?
The secret to long-lasting paint is proper storage, avoiding contamination, and an airtight seal. Depending on the type of paint, improper storage can cause hazards in your home. So, here's how you can store your paint can properly.
Store in Temperature Controlled Environment
Consider storing the paint in a closet or basement, and avoid sheds or garages. It's best to keep paint at a controlled temperature (ideally between 50 and 90 degrees Fahrenheit)—this prevents the paint from solidifying or freezing.
Seal the Paint Can Properly
Ensure the paint can is sealed properly. When closing, a single-gallon can always wipe off the excess on the lid and rim, then use a rubber mallet to secure the lid. Lastly, tap the outer edges to avoid denting the middle. You can also use plastic wrap as a gasket between the lid and paint can for a better airtight seal.
Keep Out of Reach of Children
Place the paint high, where your kids cannot reach. Also, keeping the paint somewhere high prevents the growth of mold and mildew.
Avoid Keeping Them Near Extreme Heat
Keep the paint can away from heated areas. Heat accelerates the paint expiration process, especially if you have oil-based paint. Also, solvent-based paint can catch fire if exposed to heat. So, it's better to keep them away from direct sunlight, boilers, or air vents.
What Can You Do With Leftover Paints?
Leftover paints are useful when you have teeny tiny DIY projects. Here are some uses of leftover paints:
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Touch up your walls and siding.
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Customize your furniture by coating it with a layer of paint.
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Color your planters to make your little garden more lively and vibrant.
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Add color to your accessories such as lamps, frames, accent tables, etc.
| Some Tips | If you have leftover white paint, add it with another vibrant color to create something more aesthetic and pretty - if that's your taste. |
Conclusion
Paint, like any other home improvement product, can go bad. Every paint has a specific expiration period. However, the process can be accelerated depending on certain factors, such as storage and weather. So, store your paint properly if you want it to last longer. If, in any case, the paint goes bad, don't dispose of it anywhere. Contact your local paint or home improvement center for better advice.
