I try to wait at least 48 hours before adding paint to an already painted surface. But when is the best time to sand the previous coat? Assuming the paint is dry enough to sand in 24 hours, might there be a benefit to sanding after 24 hours? The paint is softer than it would be at 48 hours, so it'll be easier to scuff up the surface (though you'll need to sand more lightly). And might scuffing the surface expose some of the inside to air? and thus speed up the drying/curing process? Or is it better to wait 48 hours before sanding.