Now that your paint project is over, you're probably wondering what to do with all that leftover paint. You can, of course, save it for touchups later. You could also donate it to local nonprofit agencies, community groups or churches. But if you just want to get rid of it, you should do so in an environmentally responsible manner.
The Difference Between Oil-Based and Water-Based Paint
Knowing what type of paint you have is important before disposing of it. The label on a paint can should indicate whether it contains oil-based (solvent-based) or water-based (acrylic or latex) paint. If the label has been damaged, read the cleanup directions. If the directions instruct you to use turpentine or mineral spirits to clean brushes or rollers, the paint is oil-based. If you're still unsure, try mixing the paint with water. Water-based paint easily mixes with water and becomes thinner. Oil-based paint separates from water.
Storing Leftover Paint
When you are ready to store paint:
1. Clean any dried or moist paint from the threads of the can and lid.
2. Cover the opening of the can with plastic wrap or wax paper for oil-based paints. The wrap seals the can and makes it easier to remove the film that forms after it has been sitting around for a while.
3. Fit the lid securely on the can and gently tap it with a hammer until it is completely sealed.
4. Turn the paint can upside down. The paint will naturally form a skin to help seal the paint and keep it fresh.
5. Paint is flammable. Store in a climate-controlled area away from heat sources. Cans exposed to extreme heat can expand causing the paint to leak. Also, keep water-based paint from freezing. Water-based paint can survive a couple of freeze-thaws, but the paint will degrade until it is ruined.
Disposing Of Water-Based Paint
Liquid paint should not be taken to a landfill or poured down a sink. Use the following method when disposing of water-based paints:
1. Fill a paper bag or box with kitty litter, sand, or saw dust.
2. Pour the remaining paint over the absorbent material.
3. Allow to dry completely in a well-ventilated area away from children, pets, and direct heat.
4. Dispose of the solid in the regular trash.
5. For paint residue in the can, remove the lid and allow to dry completely. Remove the skin and dispose of it in the regular trash. Leave the label on the can and recycle if a program is available in your area.
Disposing of Oil-based Paint and Solvents
Oil-based paint and solvents, including mineral spirits, are considered hazardous waste materials. Special precautions and steps must be taken for proper disposal. Never dispose of liquid oil-based paint or solvents in the regular trash or pour them down the sink. Some communities have special hazardous waste collection programs for liquid paint. Check your local regulations to ensure proper handling. You can also visit www.paint.org for more information.