When you are doing any home renovation, you’ll need to paint something. Most times, you can find you have old cans of paint tucked away in your garage or shed; however, you can open them to find your leftover paint doesn’t look as it did when you used it.
You may wonder if it is still usable and how long does paint lasts on the shelf. When stored properly, you can find paints can last a significant amount of time.
However, if your can is open slightly, you may think your paint isn’t any good. In our guide, you can learn more about how long is paint good for, and most of all, does paint expire?
By the end, you’ll know whether your paint can be used and what you can do to save the can from being disposed of. (Learn What is Enamel Paint)
How Do You Know If Paint Is Bad?
There are a few ways you can tell if the paint is bad, and these can come from various situations. Here is the best way to know of find out if you have bad paint.
- Bad Smelling Paint: After opening the lid, some paint can smell rancid or sour. Other paints could smell like mold. The reason for this is the growth of bacteria when the paint has gone bad, and while the paint may apply okay, the smell may not go.
- Fluctuating Temperatures: In many cases, you’ll not want to store paint anywhere it can free or be exposed to high temperatures. Such temperature fluctuations can take their toll if you have water-based paints. Even while you could thaw a paint from a cold temperature, the paint can break down if the paint will continually freeze and thaw.
- Lumpy Paint: Latex paint naturally develops a film or skin on the top after time. If your paint solidifies under the skin, then it maybe you must discard the paint. Solid paint can’t be dissolved by adding water.
How Do You Know If Old Paint Is Still Good?
Nearly everyone has cans of paint floating around their homes. No matter why you still have old paint cans, you need to know if it is still usable? Here you can find out if your paint is off and if the old paint is still usable.
If you have an unopened can of paint you have stored properly; it’s certain to be used. Unopened latex and water-based acrylic paints last up to 10 years.
Alkyd and oil-based paints last up to 15 years when unopened. The reason this happens is unopened paint keeps its ratio of liquids and semi-solids. Once it meets the air, these proportions change.
If you have a few years old paint, test brush a small patch with the paint as it could have separated. Since the paint has been sitting for so long, the compounds can split, and you will need to mix the contents using a stirrer.
Stir the paint, then test on a piece of cardboard. If the paint appears normal and goes on smoothly, you can start to use it to start painting! If you spot lumps, you can’t stir out, it is best not to use it as the chemical makeup has changed, and it isn’t suitable. (Learn How to Get Spray Paint Off Concrete)
When you need a can of paint for a project, and it can have been opened, you find the difference.
As paint is exposed to the air for long periods, it changes the composition and chemical make-up. It is this reason why old paint cannot be used sometimes. To check if yours is still okay to use, open the can and stir the contents.
Before stirring, remove the layer of thick skin that could be on top. Once removed, mix, and then test on cardboard. If it doesn’t go on as expected, it’s past its use-by date, and you’ll need a new can from the paint store.
What Happens If You Use Bad Paint?
Solvent-based paints can last with a 15-year shelf life and, if you can stir, there’s a chance it’s fine to use. If you wonder how long is latex paint good for, we have seen these have a shelf life of around 10 years so long as the conditions are not extreme in one way or the other.
If paints are colored and still have the same color on your walls, it is sensible to keep them. You can use them for touchups. If lids are loose, seal carefully; or you can transfer small amounts to small sealable. Just make certain to label with color name, number, and date you made of purchased it.
If paint has gone bad, it may not dry if oil-based and if latex, it can be patchy as the color pigment isn’t uniform through the mix.
How Do You Revive Old Paint?
You may be disappointed if you open the can to find it has dried. You can find many individuals take the chance to toss these out of the house, yet they can still be okay to use, and it has just been poor storage.
If you have an oil-based paint that has dried, then you have a chance to save it. You can find the paint isn’t the same quality, yet there are areas around the house you can use. Painting something with this paint as an undercoat can save a decent amount of money. (Read our Guide to Removing Lead Paint)
Dried latex paints cannot be fixed as easily and are best disposed of.
Here are the steps and tips for recovering your oil-based paint instead of having to dispose of it.
- Place the open paint can on some plastic sheet or newspaper to protect your room to be painted.
- Add 1 oz. of paint thinner to the paint can. You may need to add more or even less based on the amount of paint in the can. Start small and increase as it’s easier than trying to get rid of it.
- Stir paint thinner in the dried paint, and then with a paint stirrer or clean stick until the paint thickens as you stir.
- Add another 1/2 oz. or 1 oz. of the paint thinner and stir well to incorporate.
- Add more paint thinner in 1/2 oz increments until you have thinned the dried paint and reached the desired consistency.
It may be best to do this in your garage as the thinners could leave a smell and lingering odor around your house, and the fresh air of your garage makes it easier to deal with.