Paint can be conserved by storing your brush or roller between coats in an airtight plastic bag, and this can be done overnight if necessary. By doing this, it will allow you to use a second coat of paint without washing it.
Before you wash your roller, ensure to scrape any excess paint. To do this, it is best to use a putty knife or a special roller scraping tool which has a semi-circular cutout in the blade.
For water-based paint, the roller can be washed with warm water, and for oil-based paint, use a solvent. Mineral turps can be used on most oil-based paints to be washed out, but ensure you check the can for any clean-up instructions.
Squeeze and rinse the roller several times in fresh water or solvent until it stays clear. Allow the roller to dry naturally. Take note that rather than using lots of solvent, it might be more economical to use disposable sleeves for oil-based paint or varnish. Before disposing of them, leave them outside to dry.
Keep the water away from plants and gardens and dispose of the soiled water in the garden, not the drain. Ensure the water does not run into drains.
To avoid fire risk, immerse any rags or paper which have oil-based paint or solvent on them in water or leave them out in the open to dry.
Environmentally friendly ways to dispose paint:
Using up all the paint is by far the best way to dispose of it. Don’t be afraid to apply another coat if you want to, especially if this helps use up all the paint.
Being generous also helps the environment. Give any leftover paint to someone else who needs it for any community projects which may require the paint. Check with local schools, parishes or youth groups.
Don’t forget to save some paint for any touch-ups later down the track. To keep your touchup paint in good condition, you need to secure the lid tightly. To create an air proof seal around the lid, turn the can upside down and back. Keep the paint out of extreme heat or cold to make it last longer. Avoid rust being on the cans by keeping them dry, and any water-based touchup paint is best kept in a plastic container with a tight lid.
DO NOT dispose of paint or solvent down any drains, and ensure you do not pour unused paint onto plants, as this will be harmful to the plants. It is best to use a special waste collection service where available.
Many containers can be recycled when dry so it is best to leave empty paint containers open in a well-ventilated area to dry out. Check with your local council about special waste collection and recycling services.