Because it’s always best to purchase a little more paint than you need for a project so you can have a small amount left over for touch-ups, proper storage is important. Paint is a long lasting and durable product once applied to a surface but storing it has its limitations. Latex or water-based paints can generally be stored for about two years. However, if it was stored where it could be exposed to freezing temperatures, such as in a garage or shed, most likely it will be unusable. Years ago, a premium latex product could survive a freeze thaw cycle but not so with the lower VOC products of today, so always protect stored paint from freezing.
Air is the enemy of stored paint so it’s best to use a container just large enough for the amount of unused paint. The less empty space helps prevent, drying, bacteria growth, and prolongs the life of the paint. If you only have about a quart left, for example, transfer to either a quart can, glass jar or plastic container with a tight fitting lid. (To ensure a tight seal, place a piece of plastic wrap over the opening before putting on the lid.) Store in a dry location where temperatures are above freezing. Avoid storing metal paint cans directly on cement floors, as the bottom of the can will rust much faster on cement than on other surfaces such as wood or plastic shelving. Replace the lid firmly, and store the paint can upside down to prevent air from entering the container. This will keep the paint usable longer.
Be sure to write down the product and color information from the original container, for example; Aura Interior Matte Finish 522, Color AF-290 Caliente. It’s also a good idea to write the date so you know how long it has been stored.
Before you start painting with a product that has been stored for some time, check the condition of the paint. Start by opening the can and stirring well to check its consistency. If it’s smooth and creamy in the can (like fresh paint), it’s fine to use. To be on the safe side, brush out a small amount on a test surface like a scrap piece of wood or sheet rock, and allow it to dry to ensure that the paint will look and perform as expected. If your paint looks like cottage cheese or is gritty in the can, it most likely had frozen at some point and is no longer usable. If you are not sure if its OK to use, take the can back to the retailer where it was purchased for the store associate to examine.
Before using paint that’s been stored for a period of time, bear in mind that colors on exterior paint jobs or in rooms that get a lot of natural light may have faded. Check a test sample of the stored paint against the original color to make sure that there’s not significant difference.
PRO TIP: With latex paint, make sure that the paint smells clean and hasn’t spoiled. If you smell something foul, that’s bad news: the odor doesn’t go away even after the paint has been applied and dried. Don’t use the paint and dispose of it according to label directions.