It all depends on how the part is stored, cover it in plastic and keep it clean and you won't have any need to scuff for a long time. But if you have any worries at all a simple rub with a grey scotchbrite is all that's needed and you won't be removing much material. I've had Harley parts sitting for months in basecoat under plastic awaiting their next stage of color and never had any problems just starting where I left off. I wouldn't try it with some brands of base though, example: DuPont's Chromabase and Chroma Premier is a whole different animal, if complete basecoat sanding is required for any reason DuPont recomends you strip it all off and start over, they only recommend light denibbing, and if you go over 24hours don't shoot another coat of base-the reps always recommended a coat of 222S adhesion promoter say if doing graphics out past the 24hr recoat window. I did some sanding tests in the past and confirmed why the say no sanding-the paint delamed at the sanded level no matter what grit was used it was a real eye opener. I picked the brain of a DuPont rep about the failures associated with sanding their base and still have the emails-they basically said don't sand our basecoats.
