Paint can be used to spruce up your home in a variety of ways. You could change the color of your front door, paint an accent wall, or even revamp your furniture. More often than not, it is more cost effective to purchase a large can of paint than to buy a small one and potentially have to buy another one in order to finish the project. When you have paint leftover, your first question is, “How long will it keep?”
Paint that has never been used has an average shelf life of 10 years. The type of paint can affect this lifespan. Latex- and water-based paints can last up to 10 years, while oil-based paints can remain usable after 15 years.
Once exposed to air, paint begins to dry. For this reason, used paint has a significantly shorter shelf life than unused cans. Most cans of interior paints only last a couple of years after their first use.
Paint is the result of suspending pigments in liquid. Paint mixers help to adequately distribute the pigments throughout the liquid and mix them in. As paint sits unused, the solid parts separate from the liquid. Even when the liquid media is unexpired, paint can go bad. To determine if old paint is still usable, open it up, and stir it well. Then take a small paint brush and dip it in. Apply the paint to some newspaper or a piece of cardboard. If the paint appears lumpy, it’s no longer usable.
A lot of people try to gauge whether paint is still good or not by its color. The error in this method is that the swatch the paint is often being compared to is dry. Paint often changes color as it dries. Lighter pastels look more concentrated in the can and appear lighter when applied to a surface. Deeper hues appear darker once they’ve dried on your walls.
How to Store Used Paint
If you plan to reuse your paint, you’ll need to store it properly to use it in the future.
If the can your paint came in is still in good condition, feel free to keep your extra paint in the same can. Seal it up as tightly as possible. Use a rubber mallet to tap all around the mouth of the can to force the lid into place. You could also use duct tape around the lid to create even more of a seal.
When you need to use something else to store your paint, the best option is a wide mouthed canning jar. Canning jars have lids that seal tightly to keep bacteria out of jarred foods such as pickles or jelly.
When you store your paint in these glass jars, you’ll need to keep in mind that they have to be stored in a dark area. Exposure to light can break down the pigments in the paint. Keep them under the cabinet or in an arid basement.