Whether you are an interior decorator or have a knack for painting, you probably have some spray paint stocked up.
Professionals like to buy in bulk, as this saves both money and time.
You can’t get material for every order or project you’re doing, so it’s better to keep the store stocked so that you can start a project anytime you want.
However, to be able to do that, you need to keep your material fresh.
Cans of spray paint usually expire within two to three years. For some brands and types, this time frame might be shorter or longer, so it’s important to check the expiration date that should be clearly labelled on the bottom of the can.
Most people know how to keep oil paints good for long, but does the same rule apply to spray cans?
Most new artists aren’t aware of how to keep their paint cans from expiring or what can expedite the process.
Let’s look at everything you need to know about paint cans and their expiry.
How Can You Read the Expiry Date?
On average, every can comes with two dates printed at the bottom
- P (Production Date): CW for the week of production and YY for the year of production.
- EXP (Expiry Date): CW for the week of expiration and YY for the year of expiration.
It’s relatively easy to read the production as well as the expiration date on the can.
Shelf-Life of a Spray Paint Can
Now, this is a tough one. Compared to oil paint, spray cans come with a shorter shelf life.
However, different brands claim different years. For example,
- The Montana brand claims that their spray paint cans can last up to a decade without going bad.
- Other premium quality cans can last even more.
- A standard spray can have a shelf life of 2 to 3 years.
Factors that Contribute to the Premature Expiry of Spray Paint Cans
Many factors contribute to the premature expiry of spray paint cans. The following factors can affect the quality of spray paint cans and shorten their shelf life.
The immediate temperature affects the spray can the most. If it’s hot outside, the paint will dry and crack.
Cracked paint won’t come out of the can.
Apart from that, cold and humid weather also affects the can adversely, making it go bad before the expiry date.
2. Relative Humidity
Relative humidity is another reason for the paints to expire before their time.
The chemical composition of the paint can and the moisture in it are affected by the relative humidity, making the paint inside the can sticky and unusable.
Higher humidity levels make the paint stay wetter for longer; this can cause the paint to be lumpy and unable to use.
3. Direct Sunlight
When paint cans are wrongly stored in direct sunlight, they can go brittle, lose their color, or dry out before their expiry.
The reaction happens because the harsh light from the sun makes the chemicals break down and go brittle before time.
4. Aerosol Pressures
Over time, the spray can lose aerosol pressure when you open the can but don’t use it as frequently as recommended.
When you open a can but use it less frequently, the aerosol pressure is lost bit by bit. And by the time you need the can again, there will be no pressure left.
So, the paint is still intact, but you can access it without the pressure.
Over time, without the pressure to keep the seal intact, the paint has a high probability of going bad before the expiry date.
5. External Impurities
Every time you use the paint, the external particles (oxygen, dirt, ultraviolet rays) enter the can through the tube.
When these mix with the chemical inside, they create a reaction that can make the spray go bad before time.
Although this type of reaction can’t be helped, there are premium spray cans available that come with the blue back technology that keeps the external impurities out.
Ways to Make Your Spray Paint Last Longer
If stored properly, the paint cans can last until the actual expiration. There are other ways as well.
- Check Product Label Before Buying
Different brands have different compositions; if you know the label well and if you have read the instructions well, you will be able to store the can as per the label.
When stored properly, as per the instructions, the cans last longer.
- Shake Properly
If you are using an old can and nothing is coming out, don’t deem it expired; shake it well for at least 2-3 minutes and use it again. You will be surprised that most can start working after this.
As the paint gets older and stays unused for long, the color pigment settles down at the bottom.
Shaking the can vigorously, mixes the pigment again, making the can useable.
- Immerse in Warm Water
If you think your paint can have gone bad and it is coming out too thick, try immersing it in warm water.
Doing this makes the paint thin out, and it will spray just like it did when you first opened the can.
- Store Appropriately
The shelf-life of the spray paint can significantly depend on how it’s stored.
Keep your paint cans in a dry and less humid place where there is little or no direct sunlight. Always close the lid properly after using the can.
The ideal temperature to store the paint can is less than 80°F and more than 40°F.
Spray paint cans can go dry and bad if not stored properly. Just make sure you follow proper storage instructions to keep your paint fresh and useable for long.
Always check the expiration date on the bottom of the can if you think your paint might have expired. This can make all the difference between a good paint job and a shoddy one!