You found an old latex paint can in the storage and looked on the container, but you can’t find an expiration date. So you are wondering, does latex paint expire? Here is the answer to that.
Latex paints do expire but not in the same way your household groceries do. Latex paint can stay good and usable for several years. The time it takes for the paint to go bad depends on the storage conditions. This is why latex paint cans don’t have an expiration date.
So if there is no expiration date on the container, how do you know when the latex paint has expired? And is it okay to use old latex paint?
There is more to know about old latex paints and this post digs right into the topic.
Let’s find out more.
How Long Does Latex Paint Last?
Latex paint lasts between 2 and 10 years. On average, a can of latex paint lasts for 5 years before it goes bad. If stored correctly and in good condition, a can of latex paint can last up to 10 years. How long the paint lasts depends on how it is stored.
That said, how can you tell if latex paint has gone bad? Let’s find out.
How Can You Tell If Latex Paint Has Gone Bad?
There are several ways to tell if your latex paint has gone bad.
If The Lid Or Can Is Swollen
The first indication that the latex paint has gone bad is a swollen can or puffed lid. When you notice that the paint container has swollen or the lid is puffed, it means the paint has expired or gone bad.
The swollen can or puffed lid is a result of the gases being released inside the can by microorganisms. When microorganisms start to eat the paint, they give off gases that inflate the lid and container.
Related Read: How Do You Dispose Of Latex Paint?
If The Paint Doesn’t Mix Well
Another indication of bad latex paint is if the paint doesn’t mix or stir well. If you are having difficulty mixing the paint, then chances are the paint is past its prime.
Also if the paint returns to its original state after mixing it, then the paint is bad. Latex paint that has expired doesn’t stay mixed for up to 10 minutes. This is because the solvent and the paint particles will keep separating even after you have mixed them.
So if you are having to mix the paint severally, then it’s not in a good state.
If You Can Notice A Film On The Top Of The Paint
Another indication of bad latex paint is a film that forms on the top of the paint. When you notice a rubber-like film topping the paint, it means the paint has expired or is bad.
If Mold Grows In The Can
If you notice mold growing inside the paint container, then the paint has gone bad. If you also notice that the paint is covered by a hard skin or layer, it also means the paint is bad. This usually happens when the paint has been exposed to air.
Related Read: How Long Does It Take Oil Paint To Expire?
A Foul Smell
When something smells foul, it means it has gone bad. This rule also applies to latex paint. When you open a can of latex paint in good condition, you will notice a very strong chemical smell in the air. This shows that the paint chemicals are still active. If the paint smells rotten, you should dispose of it.
But sometimes, a bad or expired latex paint wouldn’t give off these signs. Your latex paint might have gone bad and it wouldn’t give off any nasty smell and the paint container wouldn’t get swollen too.
So how do you know if the paint is bad then? To know, you need to:
Conduct A Paint Test
You need to apply the paint on cardboard or a dry surface after mixing it. If the paint has any form of irregularity, lumps, or it doesn’t stick to the wall, then the paint has gone bad.
If the paint falls off the wall after applying it, it also means the paint has gone bad. If you notice that the paint doesn’t have a uniform color on the cardboard or it’s taking too long to get dry, it means the chemical properties of the paint have been changed. So the paint has expired or gone bad.
So now you know how to detect latex paint that has gone bad. But can you use old latex paint? Let’s take a closer look.
Related Read: How to Restore Frozen Latex Paint?
Is It Okay To Use Old Latex Paint?
It’s okay to use old latex paint as long as the latex paint is still in good condition. You will also need to revive the old paint so it’s smooth to use again.
Latex paints can last up to 10 years if stored correctly. So if you have a can of old latex paint, you just need to be sure it’s in good condition and can be used.
Old latex paint works just as well as a can of new latex paint. But if the can of the latex paint has been opened before or it’s leftover paint from a previous paint job, you need to inspect the container very well before using it.
If it’s an old paint can, then that means the can is not in the same condition as it was when it was sealed by the manufacturer. There might be dents and holes in the can.
If you notice any hole, dent, or opening on the container, then the paint has gone bad. Even the smallest of holes is enough to make latex paint go bad in a container. Paint cans are designed to be airtight for a reason.
You should also check if the paint was properly sealed and covered. There is a big chance you or the previous user didn’t cover the paint well the first time. Also check for other signs that the paint has gone bad such as a foul smell, swollen container, or hard layer on the paint.
As long as the old paint was stored properly, it’s in good condition and can be used. But you will need to revive the old paint before using it. How do you do that? The answer is below.
Related Read: How Long Does Primer Paint Last?
How To Revive Old Latex Paint?
Reviving old paint means making it reusable. If the paint is in good condition, you can use it but you need to revive the paint first so it can be used.
To revive the paint, you need to mix it with solvent. For latex paints, the solvent is usually water. So a cup of water or less sometimes can revive the paint. Let’s check out how to do this in detail.
1. Check If The Paint Can Be Used
The first step is to check if the paint can be used. If there is any sign of damage to the paint container, then that means the paint has gone bad. If you can smell strong chemicals and the paint particles are fully separated from the solvent, then that’s a good sign.
2. Add Water
Add little water into the paint container. Sometimes just a cup of water or less does the trick. The solvent at the top of the paint particles is usually enough to mix the paint. But we are adding water just to soften any lump and make the paint easier to stir.
3. Stir The Paint
You can use a wooden stick to stir the paint in the container. You might need to use a bit of force to stir the paint. You can also use a paint mixer to mix the paint. Paint mixers are great for old paint and you can increase the speed of the paint mixer too.
Ensure to stir the paint until you can’t see any lumps in the can. This should take about 15 minutes of continuous stirring. If properly mixed, good old paint should be fluid and color should be evenly dispersed.
Related Read: Can You Apply Latex Paint With a Roller?
4. Re-Test The Paint
The final step is to test the paint. You can test the paint on cardboard, a wooden board, or a disposable item. It’s not a good idea to test out old paint on the main canvass in case the paint is bad. It will ruin the canvass. If you are using a paint sprayer, ensure to prime the pump first.
Paint the cardboard and see how it looks. If it sticks fine to the surface, then that’s a good sign but that’s not all.
After painting, leave the paint for a few minutes to see how it dries. If it dries fine and looks smooth after drying, then you have successfully revived the old latex paint.
Related Read: Does Polyurethane Go Bad?
Does Unopened Latex Paint Go Bad?
Unopened latex paint goes bad quickly and easily. This is because the paint is not protected from contaminants and air.
When you leave a can of paint unopened, it will go bad because contaminants like dirt and dust will get inside the paint. The paint will also be affected by sunlight and moisture.
All of these will make the paint go bad pretty quickly. You will start to notice mold in the paint container. The solvent on top of the paint particles will also start to form a hard layer on the paint. If left unopened for a very long time, the paint will begin to smell foul.
When you try to use the paint, it wouldn’t mix well, wouldn’t stick well to the surface, and it will have lumps leaving you with a very ugly wall. So if you have any leftover paint, ensure it cover it tightly and store it correctly.
Related Read: Can You Use Latex Paint on Metal?
How To Store Latex Paint?
Latex paint should be stored correctly and according to the manufacturer’s instructions. This includes the proper room temperature, the right level of humidity, and an airtight container.
Latex Paint Should Be Stored At Room Temperature.
This means the latex paint shouldn’t be stored in temperatures higher than 70 degrees Fahrenheit (21 degrees Celsius).
The Latex Paint Should Also Be Stored In A Cool And Dry Room.
This means you shouldn’t store the paint can in the kitchen, bathroom, or laundry room as these rooms are usually anything but cool or dry.
The Paint Container Should Also Be Stored Away From Direct Sunlight. The UV rays from the sun will offset the chemicals in the paint and make it paint go bad.
Ensure to keep the paint stored in its container.
Paint cans are designed to be air-tight. If you can’t store the paint in its container after use, ensure to use an airtight can. You can also use plastic wrap to cover the container opening and then place it upside down to prevent air from getting in.
Storing your latex paint correctly will make it have a longer shelf life. But how can you tell if latex paint has gone bad? Keep reading to find out.
Related Read: Is Latex Paint Flammable?
Overall, latex paint does go bad eventually but it can remain in good condition for up to a decade if it is stored correctly.
So keep the paint stored the right way and when you want to use it later, check to be sure the paint is in condition. If it is, revive it and use it. Have a nice day.