I raise llamas, so I watch grass grow all the time :-)
The way that paint "dries" is as follows...
Most solvent based paint is a bunch of little globules of pigment, separated by solvent. When the solvent evaporates, the globules are allowed to come in contact with each other. When they contact each other, molecular things start to happen and they stick together.
So, first the paint "dries". That is evaporation of the solvent. At that point in time the paint is soft and not resistant to humidity. The globs are touching, but not fused together.
As time goes by, the globs of paint bond with each other. That is "curing". Typically, it takes a week or so for paint to "cure". Some types take more time, some types take less.
So, never push paint. You can add coats after 24 hours, as the solvent has evaporated. The extra coats will be able to bond with the uncured bottom coats. Don't expose the paint to humidity or contaminants for a week at least if you want best performance .
Catalytic (2 part) paints are an exception to this rule... they cure in a totally different manner.
Rick
