If you enjoy restoration work, woodworking, or you are a DIY person, I bet you could paint in your sleep, too. I enjoy creating art with spray paint, and although a friend handed me some old spray cans, I was skeptical of whether I could still use seven-year-old paint. Thus, I had to use creativity and know-how to solve this one! What do you think? Does spray paint expire?
An open spray paint container lasts around five years and loses all its pressure, preventing the use of the paint. However, the paint becomes thinner but remains usable. Sealed cans do not contain oxygen and retain their paint quality. They can last fifteen years or more with good quality cans.
Paint can be expensive, so it’s worth knowing whether or not you can use old spray paint, especially if they’re stored away in abundance. We’ll look at the shelf life of spray paint and some examples of when spray paint cans don’t work, and how to fix them. Lastly, we’ll cover some valuable tips on how to clean and unclog a spray can in case you’re having trouble!
Does Spray Paint Expire?
While the can that holds the paint expiresor ages, the paint inside can lose effectiveness, but it does not become entirely unusable. Bad paint will start to smell foul due to bacteria, and using it may leave unwanted marks on the surface and an unsatisfactory result.
Opened spray cans last an average of five years to seven years, while unopened cans may last between ten to fifteen years, sometimes more, depending on the type of paint, the quality of the container, and the process for sealing it.
The big lifespan difference derives from the effect that oxygen, heat, and moisture have on paint. An open can of spray paint is susceptible to all of these elements, causing the paint to break down over time on a molecular structure. As a result, it becomes thinner, and you may find it doesn’t take well to the painted surface.
As for the paint can, manufacturers fill them with enough pressure to remove all the oxygen to preserve the paint inside. However, opened cans start to lose their pressure over time, like a bicycle tire would if you didn’t plug the air valve. Consequently, some cans “trap” the paint inside because they don’t retain enough pressure to get it through the nozzle.
How Do You Know If You Can Still Use Spray Paint?
Scientifically speaking, spray paint shouldn’t go “bad” because the pressure removes the oxygen that causes it to age.
Most paints work by evaporating the solvents, but paint inside properly sealed cans doesn’t evaporate. While it’s true that the can’s pressurization may fail, it shouldn’t be a factor if the spray can is of good quality. In fact, the paint itself can only go bad if it cures via a chemical reaction, like ordinary paint – for spray paint, that is very unlikely.
The best way to determine whether spray paint is still good to use is to test it. Grab a different canvas, paper, or piece of material, and see whether it comes out quickly enough. You should also examine the pattern and color intensity because it can give you a good indication of what it would look like if you weren’t testing it.
If no paint comes out when you hold down the nozzle, it doesn’t necessarily mean the paint is spoiled – just that the can doesn’t have any remaining pressure. In this case, a miter saw or circular saw would make quick work of the spray can and help you get the paint inside. Afterward, you can decant the paint and apply it using an airbrush.
Is It Possible To Extend Spray Paint Expiration?
While you cannot scientifically alter the composition of spray paint, there are some practical applications and good habits that will ensure your cans of spray paint last!
First, avoid storing can spray paint upside down or lying sideways because it can affect the paint’s integrity due to the chemicals. Similarly, the paint’s shelf life greatly diminishes when storing aerosol cans horizontally or upside down on their caps.
On average, the shelf life of Rust-Oleum spray paint is around five years, starting from the production date if it’s left unopened. With bad storage practices, like placing it upside down or putting it in hot areas with a lot of moisture, five years can become two or three years. So, don’t compromise your spray paint with bad storage choices!
No Paint Comes Out When I Try To Spray: Why?
If you have old and new spray paint cans, you may find that sometimes three-year-old spray paint can have difficulty producing paint, while a ten or twenty-year-old product can work flawlessly – so what gives?
When spray paint cans lose most of their pressure, it means we need to shake them more vigorously for longer to get them to work. As such, older cans, especially those open ones, may well require a stronger shake. Rust-Oleum can be particularly stubborn and require the most shaking effort before they will concede.
You can also check the nozzle to ensure there is no dust or other form of blockage. If you believe it’s blocked but you’re having trouble unclogging it, you can try soaking the spray can in some warm water for a few minutes. When the paint heats, it becomes thinner, atomizes, and as a result, the can will spray much easier.
If you’d rather not thin the paint, you can try to clean the nozzle with compressed air to get it to unclog.
So, if you have some old spray paint cans stored away that you want to use, check to see if they’re open or sealed. If you didn’t open them, they should still work. If not, try them and if they don’t work, check the nozzle to see if there’s a blockage. If they don’t work, but you need the paint, cut them open and apply them using an airbrush.