How to prevent or remove rust on the inside of a paint can?

Question

When I complete a painting project, I usually have some paint left over in the paint can that I store for later use. After much time has passed (often year(s)) I need to do some touch-ups, and when I remove the lid from the paint can there is often a bunch of rust around the mouth of the paint can, and possibly also the lid. This rust inevitably flakes off and falls into the paint.

Is there a way to prevent this rust from forming in the paint can? If not, is there a way to remove rust flakes from paint?

Answer 1

When storing the paint cans just make sure you turn them over once every month this will prevent the walls from oxidizing. I have used this method for years and never had an issue.

It does depend on the type of paint though if you are using water based you may end up with rust regardless, enamel should be fine.

Answer 2

Store the can upside down

Or

Transfer the residual paint into a plastic container (one of those funky ones with clips on all four sides and a silicone seal ring built into the lid)

Or

Run the paint through a sieve when you pour it out for use

Or

Buy a tester pot at the same time you buy the main paint, and discard the remains in the large tin at the end of the job, keeping the tester for touch ups if you think it’s a color that will cease production

Or

Cover the surface of the paint with film or foil that extends some way up the sides of the can, like a meniscus. When opening the can, the protective catches the falling debris from the rim, and can be discarded. Some paints I've used have such a covering applied from factory; it can be retained and reused for this purpose

Answer 3

• To prevent rusting of new paint can: Stick painters tape onto the rim of can and while painting, try to smudge the brush within the tape.
• After the occurance of rust: Filter out the rust flakes immersed in the paint using old cotton/nylon cloth when to transfer the paint onto a fresh, new can.

Answer 4

Empty the can while filtering out rust flakes. Paint the inside of the can with antirust paint like Hammerite. Allow to dry. Then refill at your leisure..