Can You Use Old Paint Or Does It Go Bad? (Explained)

Opened Vs Unopened Paint

Old paint cans that have not been opened have the best chance of surviving storage for long periods.

If they are stored well, the shelf life of these unopened cans of paint can be fairly long.

This is because the paint's chemical makeup remains the same in terms of the liquid-to-semi-solids ratio, thanks to the seal on the unopened can in moderate temperatures.

Opened paint is a little trickier to deal with. While it is less likely that this paint is okay to use after a few years, it is possible when stored well.

This is because the remaining paint has been exposed to the air, which changes the ratio and chemical makeup inside the can.

Whether your old cans are opened or not, you need to open them to confirm that they can still be used.

Where Has It Been Stored - Exposed to Weather?

When it comes to storing old paints, how you store them is key to increasing paint shelf life.

Paint needs to be stored indoors out of direct sunlight in temperatures between 50 and 90 degrees Fahrenheit.

Extreme heat or cold caused by freezing in the garage or being near heaters can cause mold or poor internal chemical ratios to occur, making the paint unusable.

Some older paints with antifreeze with VOCs  (volatile organic compounds) or mildewcides may last longer but are still susceptible to mold or damage.

Ensure that you line the top of your paint can with plastic wrap before sealing it and placing it on high shelves indoors to protect both the paint and your family.

Lifespan Of Paints

How long does paint last? The lifespan of leftover paint or how long does paint last varies depending on the paint types and long does paint last well it has been stored.

The general average for common paints tends to be five years if stored well, depending on how old the formula is. We have provided some estimates as a general guide below.

Can I use 2-year-old paint? Can I use 5-year-old paint? Does Benjamin Moore paint last in the garage?

It depends on whether the paint is still in good condition after years of storage.

If the leftover paint has gone bad, you need to dispose of it and not use it on your walls or painting projects. Store paint well, and it should have a long paint shelf life.

Yes, old paint can go bad when not stored properly. Extreme temperatures and broken seals play a role in paint going bad.

For instance, you may see that old exterior paint separated in the can over time.

Signs that an old can of paint is still usable or your old paint is still usable include:

If each of these is present, you can move on to testing, mixing, and straining. Your paint may have a thickened skin of paint scum, but that is nothing to worry about necessarily.

Properly Sealed and Covered Paint Cans

When storing paint, extreme heat and weather elements are not acceptable.

Properly resealed and covering your paint can correctly helps extend its shelf life and ensure it does not dry or mold.

Lay a thin film of cling wrap across the top of your paint cans paint stick before hammering the lid down helps prevent the liquids from evaporating and bacterial growth from getting inside.

Avoid denting the can while using the rubber mallet, as that can lead to micro punctures that render your seal ineffective.

We recommend also labeling any new paint or opened cans with the date of purchase with a permanent marker. This can help you easily keep track of the shelf life and paint store time.

It is quite easy to tell when the paint has gone bad. Even paint that has been sealed properly can be useless when not stored correctly.

Expired paint tends to have one or more of the following qualities regardless of paint type or type of paint:

If you find any of the above in your old paint, it is considered hazardous waste and must be disposed of safely.

No matter how long the paint left in the can has been stored, it must go through the proper disposal channels, and you will need to purchase more paint.

Before you begin, it is vital that you spread a tarp on the surface under the can and on anything you do not want to get splattered paint on.

Wear paint-project-appropriate clothing and properly ventilate the space for safety.

Do not shake the can before opening it. We recommend wearing gloves and a paint mask for protection as you pry open the can.

You may need help from other tools to help lift a crusted-on lid and screw on lid. Laying an old rag over the top can cause any splatter to go on the rag rather than yourself or the room.

Find a popsicle stick or other similar tool to gently stir the paint, checking the consistency, smell, and texture as you go.

It is at this point that you decide whether the paint is safe to use or if you need to properly dispose of it. If everything seems good, continue to the next step.

It is at this point that you can choose to stir your paint vigorously or strain it. To stir it, we recommend renting or purchasing a paint stirrer and letting it stir for 5 minutes.

Ensure that the head of the stirrer is kept under the surface to prevent it from going everywhere.

To strain your paint, you can choose to find a large plastic container and use either a large professional paint strainer or old pantyhose stretched over the top.

How much paint you need to get through will decide how large the strainer and container need to be.

Slowly pour the old paint into the container, taking it slow and avoiding spilling. Let the paint slowly seep through until it is complete.

In some states, you can take your can back to the paint stores you got it from or the painting company, and they can use an industrial mixer for you.

Not all places do this service, so it is important to call ahead to save a wasted trip.

Even if they can't mix the old paint for you, they can likely use details from the paint can to make you a match.

Once you have confirmed that the paint is smooth and there are no more issues with the consistency, you can move on to testing.

Get a small paintbrush and some old cardboard and paint a layer or two before leaving it to dry.

Old paint that has gone bad will not stick properly, dry poorly, and will smell off. If all dries and sticks as it should, you are free to do any touch-ups or projects you want.

It would be best painting tips you didn't use interior paints or exteriors paint that has gone bad, as it is considered hazardous waste.[1]

We cannot overstate the dangers of using old paint, particularly moldy formulas.

In general, if your state has a county disposal facility near you that deals with paint, we recommend taking it there.

However, the type of paint you need to get rid of does inform what you need to do.

Oil-based paints are one of the trickier to remove. Modern law means that you cannot simply leave the oil paint or oil based paint can in the garbage, and some laws are different depending on the state.

You must never pour oil-based paints down the sink or toilet as they may block the drain, poison the system, or harm the local soil and water.

The best way to dispose of oil-based paint is to take it to the nearest waste disposal facility or to contact your local paint stores to confirm if they have a paint recycling policy.[2]

Water based latex paints or water-based acrylic paints are easier to remove.

Depending on your area, you can take it to a facility, recycle it in-store, or dry it up before leaving your unopened latex paint for the county garbage truck.

Check your state's recycling and acrylic paint waste disposal laws to ensure you do it correctly. 

To dry your latex paints, simply leave them out to dry, add hardening powder[3], or dump kitty litter or shredded newspaper into the latex paint.

Whether you naturally dry the latex paint or help it along depends on how much paint you need to dry.

Chalk paint, alkyd paint, latex paint, and milk paint removal policies tend to vary, but most states tend to advise the recycling program or waste facility method.

In short, how you store paint decides how long paint lasts in storage.

When purchasing cans of paint, always mark down when you bought and opened it with a marker, and seal it correctly.

Properly sealing and storing your paint ensures that you can save money without having to buy a new can every few years for touch-ups.

References:

1. https://www.epa.gov/environmental-topics/land-waste-and-cleanup-topics
2. https://www.paintcare.org/
3. https://www.rustoleum.com/product-catalog/consumer-brands/krud-kutter/paint-prep-and-clean-up/waste-paint-hardener
4. https://www.homedepot.com/b/Paint-Paint-Thinners/N-5yc1vZc5bm