We inherited gallons of old paint when we bought our house a decade ago. Those cans, along with others we purchased ourselves and didn’t finish, are corroding. Last year, I blended many of those cans in big plastic buckets and ended up with ten gallons of strange, Silly Putty-colored paint. I might have a paint shop add some concentrated color to make it gray, and then I’ll paint the basement walls.
A few of the remaining cans need to go, so I’m using what I can and drying out the rest before I throw it away. I dried a dozen gallons of ruined paint last summer using kitty litter, which rapidly absorbs the moisture and turns into a kind of crumbly cement. This time I’m just painting a set of decrepit boards, over and over.