Every homeowner eventually faces the issue of what to do with leftover paint. How do you store it, how long will it remain usable, and how do you dispose of it? Will a sample be needed to pass on to future owners if the home is sold.
To keep or dispose
Keep only the paint that you will likely reuse. After a fresh paint job, it’s always a good idea to keep a quart-sized can or container for later touch-ups. Keep larger quantities if you intend to extend the first paint job to other areas later. Keep in mind that the paint already on the wall will fade over time, so a later touch-up with leftover paint may show if you wait too long.
How long will paint last?
Latex paint, most commonly used on Sheetrock walls, will remain usable for as long as 10 years if stored properly. Oil-based paint, typically used on wooden surfaces like doors and molding, can last much longer.
Proper storage of leftover paint
Store paint you intend to keep in a consistently cool environment. Extremes of heat and cold can render it unusable. In the cold, latex paint will develop a skin on the surface and tend to separate, requiring vigorous stirring to determine if it’s still good. Extreme heat can harden it. Oil-based paint will fare better, but extreme heat is never a good idea given the paint’s volatility.
Before replacing the lid on a can of paint, wipe around the lid groove. Place a sheet of plastic wrap over the opening of the can, then tap the lid into place with a rubber mallet. Don’t store paint in metal cans on a floor where they could be exposed to water. If the can bottom rusts, paint could leak.
If you’re keeping only a small amount of paint, transfer it to smaller container to save space. Create a label for the new container showing the brand name, color code, date purchased and the area of the house where the paint was used. Put a dab of the paint on the label or lid for reference. Even better, use a glass jar so you can see the paint. These samples will come in handy if you need to refresh your walls when staging your home for sale.
There are several ways to dispose of paint. If the quantity is very small, simply leave the lid off and allow it to dry in the can. This works best with latex. Also with latex, if you have half a can or less, you can mix in an equal amount of cat litter to absorb the paint, then toss in the trash.
Oil-based paint is made with petroleum derivatives, so your best move is to dispose of it with experts. You can check for proper disposal locations in your state. Many large cities have municipal disposal sites for household chemicals.