You have probably heard the cliche that paints don’t expire but is this true with spray paints? Here is the answer to that.
Spray paints do expire and you can see the expiration date on the bottom of the container. Spray paints have a best before date. Usually calculated from the date the paint was manufactured.
However, the expiration date inscribed on the bottom of the spray can doesn’t guarantee how long the paint will last.
That’s because storage conditions, heat, and humidity can affect the spray paint making it expire before the date on the container. Also, if stored correctly, the spray paint can outlast the expiration date on the spray can.
Does Unopened Spray Paint Expire?
Unopened spray paint does expire eventually. This is because of the chemical composition inside the spray cans. Spray paints are developed from a blend of several paint chemicals, pigments, solvents, and preservatives all compressed inside a spray can.
The different chemical features and reactions of these compounds inside the spray can give spray paint a limited shelf life. While other paints such as latex and enamel last well over 10 years if left unopened, most spray paints expire in less than 5 years if left unopened.
Generally, unopened spray paints have a shelf life between 2 years and 10 years. Brands like Ironlak and Krylon expire between 2 and 5 years. While brands like Montana guarantee a shelf life of 10 years if left unopened and stored properly.
On average, unopened spray paint will go bad in 3 years (or 36 months). You should know that the shelf life of unopened spray paint is subject to storage conditions and temperatures.
Spray paints are made from a blend of several paint chemicals and pigments. These include colorants, solvents like acetone, xylene, and other paint molecules. The spray also contains a host of preservatives that are used to keep the paint from going bad or solidifying inside the paint can.
Not just that, spray paints are designed with a pea made from either metal, plastic, glass, or marble. The pea is used to mix the paint inside the container so a blend of all the particles comes out when the valve is pressed.
All of these chemicals and compounds are locked together inside a spray can filled with pressurized air. The reaction of compounds to different storage conditions and the varying chemical features makes the spray paint unstable. This is the main reason spray paints don’t last very long.
Can You Use Expired Spray Paint?
You can use expired spray paint but it’s advised to shake the spray container for at least 90 seconds before using it. This is to allow the pea inside the paint container to mix the dead paint particles properly.
Also, you should test out the spray paint by covering a dispensable area or object first. Then, see how the paint comes out, dries, and how the finish appears before you go ahead to use the paint on the object to be painted.
Spray paint doesn’t expire the same way your groceries do. When spray paint is perceived to have expired, two things might or will have happened. First, the paint can or might have lost pressure.
As explained earlier, spray cans are filled with pressurized air or gas which dispenses the paint when you press or pull the valve. Expired spray paint might have lost all pressure meaning that the paint wouldn’t come out when you press or pull the valve. This will cause the nozzle to become clogged.
Secondly, the spray paint might have hardened inside the paint container in which case it can’t be mixed when you shake the spray can. For the first scenario where the paint can doesn’t have any pressure, you can de-can or tear the spray can carefully to pour out and use the spray paint.
When the paint has hardened, you can also de-can and thin the spray paint with mineral spirits to give it a liquid nature so it can be applied.
However, you should know that not all expired spray paints expire should be used. Some spray paints will turn toxic after the paint has expired. This is very common with graffiti spray paints. So to be on the safer side, always check and test expired spray paint before using it.
How Long Does Spray Paint Last After Being Opened?
After the spray has opened, spray paints are known to be halved in terms of their shelf life. So, if the spray paint will last 3 years (or 36 months) if left unopened, the shelf life will reduce to 18 months or less after the paint has been opened.
On average, spray paint will not last up to a year after the paint can have been opened even if you store it properly. This is because the content in the spray cans will be exposed to dry air and air regardless of how small will still cause paint to solidify over time.
Not just that, opened spray paint will also be more prone to the elements especially temperature changes and moisture. This will affect the state of the paint inside the paint can. That will cause chemical reactions, paint solidification, and separation inside the paint can.
The reason why unopened spray paint lasts longer than opened spray paint is because the spray can will not be affected by the environment. This is because the paint is still sealed.
But when the spray can is opened, dry air and other environmental factors like moisture, heat, and humidity will affect the paint. This is because the seal of the spray can has been broken. Since the seal is broken or off, the paint will go bad quicker due to the reaction of the paint chemicals to the atmosphere.
However, if you store opened or used spray paint in a cool room and away from direct sunlight, the paint will last longer. You should also store the paint away from dusty environment, moisture, and ensure to seal the cover tightly in place. With proper storage conditions, opened spray paint can last over a year.
How Do You Get Old Spray Paint To Work?
To get old spray paint to work, you need to revive the paint. There are two main methods to do this and this guide will show you how to go about it. The first method is simply to…
Method 1: Shake The Paint Can
If you are familiar with spray cans, then you’ll be familiar with the sentence “shake before use.” This is because the content in the spray can need to be properly mixed for even distribution.
This can also help to get old spray paint to work. Simply hold the paint can firmly then shake well for about 2 minutes. While you shake, the pea inside the paint can will stir the paint particles together producing an even consistency and paint color.
After shaking the can, clean the spray can nozzle with a paint thinner like turpentine or mineral spirit. This will help loosen the clogged paint particles on the nozzle so when you press the valve, the paint will come out nice and smooth. Let’s check out another method to get old spray paint to work.
Method 2: De-Can And Thin The Spray Paint
The next method is a bit more complex than the first but it’s nothing you can’t handle. This method is advised for old spray paint that has hardened in the container or that doesn’t come out when you press or pull the release valve.
For this method, you’ll have to open the spray can, pour out the paint inside, and thin it so you can easily apply it. To use this method, you’ll need a few tools and supplies:
- A sharp object or a small drill bit
- A scissors or cutting material
- Paint mixer or turning stick
- A paint bucket
- Paint thinner
- A paintbrush
- A pair of thick gloves
Here is a quick rundown of how to de-can and thin spray paint:
- Drill a hole or puncture the top of the spray can
- Wait for pressured air to escape
- Cut an opening starting from the drilled hole
- Pour out the spray paint
- Add a paint thinner
- Stir for a few minutes with a paint mixer
- Test out the paint
Now, let’s get to work.
1. Drill A Hole At The Top of The Paint Can
The first step is to puncture the top of the can. For this, you’ll need a sharp object like a nail but it’s advised to use a drill bit. Just drill a small hole at the top of the paint can. Be careful while doing this to prevent injuries.
2. Wait For Pressured Air To Escape
When you puncture the spray can, the air is sure to bleed out. You should wait until the air comes out fully. After you drill a hole, you’ll hear a hissing sound for a few seconds. This is the sound of air escaping from the spray can. When you can’t hear any hissing sound anymore, you should then…
3. Cut An Opening In The Can
The hole you drilled is to bleed the pressured air inside the spray can. The next step is to cut an opening so that you can pour the paint out easily.
To do this, you can use large scissors. Just make a small slice or cut at the top of the spray can where you drilled the hole earlier. Be careful with this as the spray can will be sharp once it has been cut.
4. Pour Out The Paint
The next step is to pour the paint into a paint bucket. To do this, turn the paint container upside down. The paint inside the container will rush out into the paint bucket. If the paint doesn’t come out, it means the paint has solidified inside the spray can.
In most cases, this means the paint can’t be used anymore. To be sure, slice through the entire paint can with the scissors used earlier.
Then empty the spray can. If the content is hard and Stone-like, you should toss it out and buy a new spray paint. But if the content appears thick or is riddled with lumps, it means you can still revive it by carrying out the next step.
5. Add A Paint Thinner
A paint thinner or solvent is a liquid substance used to make thick paints lighter and easier to apply. For water-based spray paints, the paint thinner will be water.
So add a few cups of water to the paint you poured out. However, most spray paints are oil-based. For oil-based spray paints, you’ll need mineral spirits, turpentine, or white spirits.
6. Stir The Mixture For A Few Minutes
You should use a paint mixer for this as you are guaranteed better results. But if you don’t have access to one, you can use a turning stick to stir the paint mixture together.
You should stir for at least 2 minutes or until you notice the paint and thinner are well mixed. When you have an even consistency and color, you can stop stirring. Then you should…
7. Test The Paint
Test the mixed paint on cardboard or wall. To do this, use a paintbrush to apply the paint. If the paint goes on well and the finish looks good, then you have successfully revived the paint and you can go ahead to use it.
What Happens When Spray Paint Expires?
When spray paint expires, the paint usually becomes unusable. This is because expired spray paint will:
- Lose pressure: most times, expired spray paints will lose air pressure inside the can so when you press the valve, nothing comes out.
- Solidify: expired spray paint also tends to become hard or lumpy inside the spray can
- Become Toxic: expired spray paints are known to produce very toxic fumes that shouldn’t be inhaled or come in contact with the skin.
How To Know If Spray Paint Is Expired?
To know if spray paint has expired, check for the following signs:
A swollen or puffed container:Since the paint has expired, the paint container will appear swollen or puffed. That’s due to gases being released inside the spray can by paint-eating microorganisms.
Foul Smell: if you spray the paint and catch a strong foul whiff or rancid odor, the paint has expired or gone bad.
Uneven consistency: when you spray expired spray paint, the paint produced will have uneven consistency and color.
Streaky Paint: The paint will appear streaky as some parts will appear thicker than others. Also, the color will vary and some parts will dry faster than others.
Clogged Nozzle: Expired spray paint will have a clogged or blocked nozzle. Also, the valve will be very hard when you press it. This is because the paint has hardened underneath. This is more commonly with opened spray paints.
Related Read: Does Spray Paint Freeze?
Does Rust-Oleum Spray Paint Expire?
Like all other spray paints, rust oleum spray paint also expires. The shelf life of rust oleum spray paint is between 2 and 5 years from the production date. On average, rust oleum paint expires 3 years after the paint was produced.
The reason for a shorter shelf life of rust oleum spray paint is because the spray paint has an increased amount of paint chemicals.
Since the paint is designed to prevent rust and be used on different types of surfaces, it includes a host of other chemicals in its formula which adds to the slight instability of the paint.
If left unopened and stored well, rust oleum sprag paint can last over 3 years. Once opened, rust oleum spray paint doesn’t last up to a year.
Related Read: How Long Does It Take Spray Paint To Dry?
Overall, spray paint expires. It’s hard to see any product or paint that doesn’t expire. But, one good thing with spray paints is that you can see the expiration date on the bottom of the spray can.
This helps you to figure out the time you have before the paint goes bad. Though you can use expired spray paints, it’s advised to check and test the paint first as some spray paints become toxic once expired.