When it's time to clean up the basement, don't throw away those dusty old buckets of paint and primer. If the can was snugly closed and sealed, you can probably revive the paint for future use. Old paint separates, however, so it must be thoroughly stirred up prior to use. You can request that service from your neighborhood paint retailer, or you can perform that chore yourself with some basic tools.
Is the Paint Still Usable?
Modern coatings are formulated with enough biocides and preservatives to produce a 10-year shelf life -- under ideal conditions. Conversely, if the paint was exposed to temperatures below 35 or above 100 degrees Fahrenheit, it is not trustworthy. If the stored paint was previously thinned with water or contaminated with dirt or rust, don't use it.. If the paint smells like spoiled food when you remove the lid, it's time to dispose of it. And if the paint is no longer liquid, it's ready for disposal.
Let the Dealer Stir It
If your old paint can has never been opened or is nearly full, the retailer that originally sold you the paint is often willing to re-mix the paint at no charge using their high-performance blenders and shakers. When you take it home, the paint should perform like new with its color unaffected.
Stir It Yourself
When the paint is only a few months old, it may show some separation, but you can blend it to optimal condition using the free stirring paddle supplied by your retailer. But paint that's been stored between six months to 10 years needs to be more thoroughly stirred up.
Things You'll Need
Clean, lint-free cotton rag
Paint stirring drill bit
Paint thinner (optional)
Step 1: Clean the Lid and Rim
Lay the can on a dropcloth or some old newspaper. Wipe the top of the lid clean, and wrap a clean cotton rag around a flat-blade screwdriver head to clean the rim. Carefully scrape off any dried paint, rust or corrosion from the rim before opening.
Step 2: Remove the Lid
Position the edge of a flat-blade screwdriver under the lid's rim and partially pry it up from the can. Repeat in three or more locations around the can's perimeter until the lid is free. Put the lid aside for later.
Step 3: Gently Stir
Insert a wooden or plastic paint paddle into the can and gently stir the contents. If the paint fluids and color seem evenly dispersed, it's ready to use.
Step 4: Power Stir
Mount a paint mixing attachment to a variable-speed drill. Insert the attachment deep into the can and turn on the drill at low speed while slowly moving the mixing attachment around the perimeter of the can's bottom. Gradually increase the drill speed to medium, then turn off the drill after about a minute. After the drill has completely stopped, slowly remove the attachment from the can and allow any leftover material to drip back into the can.
Step 5: Finishing Steps
Clean the mixing attachment using the appropriate solvent: running water for latex paint or paint thinner for oil-based paint. If you don't plan to apply the paint immediately, replace the lid and gently hammer it into place with a rubber mallet.
Mike Matthews is editor of Green Building Product News, a national publication that covers sustainable innovations in building and remodeling, and he has spoken at national conferences on green building. He has also served as founding editor of "Paint Dealer" magazine.