If you’re painting at home, you can bet you’ll have some paint left over. You might think it’s easy enough just to throw everything in the garage and call it a day. Paint lasts forever, right? Well, not quite.
Once a can of paint has been opened, you can store it for around two years. If you have leftover or opened paint, store it in a cool, dry location and ensure the container is tightly sealed. The paint’s life span can also vary depending on the type of paint you have.
The paint is a bit more finicky than we may think. Not only is it sensitive to freezing and very hot temperatures, but humidity can also play a role in paint going sour. So, what do you need to know to get the most out of your supplies? Read on to learn more.
How Long Will Paint Last After I Open It?
It’s often the case that you’ve got at least some unused paint after a job. Regardless of how much you’ve got leftover, storing paint for future touch-ups is a fairly common practice among homeowners. A common question that comes up is how long that stored paint can last after it’s been opened.
When it comes to storing paint, you’ve got quite a few years, depending on the storage conditions and the type of paint. With proper storage, you can expect up to 2 years of safe storage.
It’s not very often that you need to repaint a room. But if you store your paint correctly, a few touch-ups or updates every few years shouldn’t be an issue. Of course, you’ll still want to make sure the paint hasn’t gone bad… but more on that later.
If you don’t open your paint, it can last up to 15 years. Again, this will depend in part on the type of paint you’re using and the conditions in which you’re storing it. Solvent-based oil paints have the longest shelf-life at about 15 years. Acrylic and latex-based paints, meanwhile, can last around 10.
Unfortunately, paint does go bad after a while — even if it’s unopened. So, what can you do to get the longest life out of your paint?
How Should Paint Be Stored After Opening?
So you’ve just finished remodeling the bathroom. The last coat of paint is on the wall, but you’ve got a good bit of paint left in the can. You know you’ll probably need it later for touch-ups, and you don’t want to buy a new can just for that purpose. What’s the best way to store that opened can for future use?
To store paint after opening, seal the container tightly. A proper seal is essential to keeping the paint safe during storage. Moreover, you’ll need to keep the paint in a dry, cool place. Temperature extremes can damage the paint, so keep that in mind.
Paint storage starts with an airtight container. This is important because the solvents in the paint need to stay within the mixture and not evaporate into the atmosphere. Those solvents help the paint stay smooth and usable. The more they evaporate into the dry air, the more likely the paint will go bad.
Storing paint in an airtight container is as simple as closing the can lid securely. If you don’t have a lot of paint left in the can, you can move the paint into another container if necessary.
For small amounts of leftover paint, consider these paint storage cups (on Amazon). And if your original can is unusable, you can always get a replacement such as this 1 Gallon All-Plastic Can (also on Amazon).
The next critical step is storing the can in proper conditions. In most cases, you don’t want to either freeze your paint or leave it in high temperatures. While freezing and high temperatures might not affect all paints, as a general rule, you should keep paint away from these extremes. This means keeping paint outside of common storage areas like sheds or garages.
If you can, keep your paint at around 70-80 degrees or room temperature. Find a space inside for best results.
How Do I Tell if My Paint Has Gone Bad?
So, you’re ready to pop open that can of old paint and fix up some spots on the wall. But how can you tell if your stored color is safe to use again?
You can usually tell when the paint has gone bad. It will be clumpy, and it might smell bad. You may also see visible signs of mold. If you see any of these signs, your paint is probably not good anymore.
It’s worth noting that paint will usually separate in long-term storage. The solids and liquids will naturally separate, and this doesn’t mean anything has gone bad. After you open your paint, make sure to give it a good stir. Reach all the way to the bottom of the can, where the solids tend to settle.
If you see clumps after stirring, your paint is bad. If you can’t really tell, try and use a brush and do a test paint on some newspaper. If you see visible clumps on the test strip, you can bet it will be lumpy on the wall as well.
The next thing you might notice is a bad smell. Again, it’s natural for the paint to smell like chemicals. It’s not natural, however, for the paint to smell rancid or sour. This is a sure-fire sign of bad paint. With some paints, like latex, this smell can become even stronger over time if you use it on your walls — so watch out!
Lastly, you might see mold in the paint. Since some paints use water as a base, mold has a chance to take hold and start colonizing. If your paint has mold, don’t use it.
Is It Okay to Use Paint That Has Gone Bad?
Okay, so you’ve got a pretty small spot to touch up, but the old paint is looking suspicious. Can you go ahead and use it anyway?
Bad paint usually means it won’t perform as intended. This means lumps, weird textures, strange smells, and much more. You might be able to get away with certain levels of bad paint, but generally, it’s unusable.
Again, if you’re really looking to get some use out of your old paint, consider doing a test run. You don’t have to paint anywhere important. You don’t have to paint on the wall at all.
Mix up the paint very well, try to get out as much of the clumping as possible before your test, and then paint a piece of paper or cardboard. Let the paint dry and observe the results.
Does it look smooth? Are the colors consistent? Is there still an off smell? If not, you may be able to get away with using the paint in small areas. If you can, use the paint as an undercoat.
However, if the paint is too dry, it can’t be saved. Consider buying a new batch if you notice significant drying when you open the old can.