Does Spray Paint Expire? Yes, Here's What to Know
Author: Omar Alonso | Editor: Omar Alonso
Review & Research: Jen Worst & Chris Miller
You finish your latest project and decide it could use a coat of spray paint. You remember you have a can of black spray paint in the garage from a few years ago, but does spray paint expire? Have you left it in storage for too long, or can you still use it?
Typically, spray paint doesn't last as long as liquid paints when applied to a surface, but it's in a sealed can, so it must still be good, right? Since you're not exposing it to air, spray paint has a long shelf life, but it varies between brands and types of paint.
How Long Is Spray Paint Good For?
Usually, you can have spray paint in storage for as long as ten to 15 years without it going bad. However, there are plenty of other factors determining its shelf life that we discuss below.
Understanding the Chemical Composition of Spray Paint
Before we look at the longevity of various types of spray paint, we need to consider its chemical composition. What does spray paint consist of, and do its ingredients go bad?
The pigment in spray paint is what gives it its color. The pigments can be color, pigments, functional pigments, or inert pigments. Pigments are short-lived, and they typically have a lifespan of around 15 years. After that, they degrade, changing the color and consistency of the paint.
The binder in spray paint enables the hardening process after use. It facilitates the formation of a hardened layer, creating a film left behind after the paint dries and cures fully. The quality and quantity of the binder used in the spray paint formulation affect its durability and service life.
The binders also determine the adhesion of the paint, its washability, gloss retention, and fade resistance. Most spray paint manufacturing brands use alkyd, epoxy, and acrylic polymers as binders.
The solvent is the chemical carrying the paint ingredients. Manufacturers use water or organic solvents to carry the paint.
When you depress the nozzle on the spray can, the propellant drives the paint through the nozzle and onto the surface you're painting. The propellant expands quickly as the pressure is released from the can when you press the nozzle. Chlorofluorocarbon (CFC) gas was the primary propellant used in earlier versions of spray paint.
However, its adverse impact on the ozone layer caused manufacturing brands to switch to alternatives like tetrafluoromethane and hydrofluormethane. However, these propellants aren't stable and react with other chemicals. HFCs are chemicals with short lives of approximately 15 years in stable environments. You can't push the paint out of the can when the propellant degrades.
How Can You Tell If Spray Paint Is Still Good?
Does spray paint expire? Yes, and if you want to know if the paint is still good, take an old piece of wood or cardboard and use it as a test surface before painting our project. Here's what you should expect when testing the paint.
- Pigment quality – The color should be consistent across the sprayed area.
- Spray pattern – The spray pattern should have no drips or spatters and be even and smooth.
- Drying time – The paint should dry evenly and fast without being tacky or leaving residue.
- Viscosity – When applied correctly, the viscosity should be even and not run or clump.
How Long Does It Take for Unopened Spray Paint to Expire?
Unopened spray paint cans should typically be good for two to ten years, depending on the storage conditions. The lifespan varies between brands, and some are shorter than others. Check the expiry date on the can before you use it.
How Long Does Spray Paint Last After First Use?
After you open the can of spray paint, it starts to degrade. Typically, you can expect the paint to expire after two years, but some brands may last only a year before the components in the spray paint break down, becoming unstable and unusable.
The general rule of thumb is that opening and using the can halves the paint's lifespan. However, it depends on the storage conditions and the manufacturing brand.
Do Changes in Temperature Cause Spray Paint to Expire?
How you store spray paint plays the biggest role in its longevity and service life. Temperature is the biggest concern when storing the can. When paint gets exposed to high temperatures, such as direct sunlight, it causes changes in the pigmentation and the color of the paint.
This process is known as "thermochromism." The pigments degrade, and the paint loses its original color. Plus, storing a pressurized can in direct sunlight isn't a good idea. The heat can cause the chemicals to expand, causing the can to explode or rupture.
High-temperature exposure also causes degradation of the propellant, meaning the paint won't come out of the can. Even if it does, it won't have its original color or consistency.
How Do You Know if Spray Paint Expired?
Three are three main methods to check to see if your spray paint that's been sitting in your garage for who knows how long is still good to be used.
Check the Expiration Date
Most manufacturing brand stamp the expiration date on the bottom of the can. If the paint is past the expiration date, it's probably useless, but you can always use our method of testing it mentioned above. Depending on the standard paint can size you have (there are multiple) the expiration date may be printed on the label or on the bottom of the can itself. You'll never find it on the lid.
Shake the Spray Paint Can
Shake the can before using it. A small plastic or steel bearing inside the can agitate the ingredients, mixing them before use. If the bearing doesn't move freely or the can doesn't shale well, it's probably expired.
Test the Spray Nozzle
Check the nozzle to ensure the paint can move freely through it. If it's clogged, it will affect the performance of the paint. If there is a clog, soak the nozzle in some paint thinners or poke it with a pin before reattaching it and using the can. Does spray paint expire? Yes, but even before that the paint can dry in the tube and nozzle, making the can useless. If you get spray paint on concrete doing this, don't worry, it can be removed.
How Do You Store Spray Paint Properly? & Tips for Use
Let’s take a look at exactly what you need to consider during and after purchasing spray paint to ensure it’s not already expired and how to store it so you can get the maximum lifespan out of it.
Check the Spray Paint Expiry Date Before Buying
Check the manufacturer's expiry date before you buy the can. If it's under a year to expire, consider buying another brand or visiting another hardware store. Some stores might leave the paint on the shelf for a year or more before someone buys it, shortening its service life.
Appropriate Spray Paint Storage
How you store the can plays a significant role in the longevity of the paint. Keep it in a cool, dry environment, away from direct sunlight. After opening the can, replace the lid tightly before putting it on the shelf.
The ideal storage temperature for spray paint is between 80 °F and 40 °F. Always store the can upright, don't lay it on its side. Is paint ruined if it freezes? Not always, so test it out. It may and likely is still okay.
Shake the Can Properly Before Use
Shake the can well before use, especially if it's been sitting for a while. We recommend shaking the can for at least two to three minutes before using it. The pigment settles to the bottom of the can as the paint sits in storage. Shaking the can mixes the pigment into the other ingredients, making it usable again.
Immerse the Can in Warm Water Before Use
If the spray paint is coming out too thick, or the can isn't working properly, leave it in a bowl or bucket of warm water for ten minutes. The heat thins out the pigment and helps with mixing when you shake the can.
FAQ’s Regarding Spray Paint Expiration
Does spray paint expire? How long does spray paint last? Does spray paint go bad? Let’s cover all these topics surrounding spray paint shelf life.
Where Do I Find the Expiration Date on a Can of Spray Paint?
Manufacturers usually stamp the expiration date into the bottom of the can or stick a label on the underside showing the expiration date. If you see a code on the can, such as B0529BHLFPMQX65VOC. In this example, the characters identifying the expiration date are the first four digits, or 059. The first three numbers indicate the day of the year (05 = 5th day of the year, i.e., 1st January). The fourth digit indicates the year of expiration (29 = 2029).
Can You Use Expired Spray Paint?
Whether the paint is expired depends largely on the storage conditions. If you follow our guide to prepping the expired can before use, and it comes out with the right color and consistency, it's good to use. However, it's important to remember that this might be the last time you can use the can, so use it all up if possible.
Can Breathing Spray Paint Fumes Harm My Health?
Yes. Spray paint contains harmful chemicals and VOCs. Prolonged exposure to paint fumes can lead to adverse health reactions. Some people report experiencing a narcotic effect when breathing in the fumes., However, prolonged exposure can lead to symptoms like nausea, headaches, dizziness, and even seizures. Using a respirator when using spray paint in enclosed environments is best.
Can I Spray Paint Over Rust?
Yes. You can spray paint over rust, provided you remove all the corrosion from the metal and prep the surface properly for paint. Painting over the rust directly without preparing the surface can result in rust bleeding through the color. You can spray paint over chrome and many other materials that can accumulate rust.
Key Takeaways Regarding Spray Paint Expiration Dates
- Yes. Spray paint does have an expiry date.
- Depending on the manufacturer, spray paint can last anywhere from two to 15 years.
- How you store the paint plays a significant role in extending the longevity of its service life.
- If you've opened the can, the spray paint will expire in around a year or two.
- If you're using old spray paint from an opened can, shake it vigorously for two minutes before using it and check the nozzle for blockages.
So, Does Spray Paint Expire?
Yes, like other goods based on chemicals, there is an expiration date listed on the label or can. The chemical composition can break down over time and alter the ability of the spray paint to perform its job properly. You can find the expiration date on the labels. So does spray paint expire? Absolutely, but it lasts longer than you may expect.