Jeff,
I would have to say it really depends on the exact type of paint you're
spraying over and what you're spraying. If the paint currently on your MV
is flat or maybe even semi-gloss (semi-gloss is somewhat debated), you
won't have any problem. (Assuming the spray-paint isn't latex, which I'm
pretty sure it isn't.) If the paint currently on there is glossy, you'll
have to dull the surface with VERY fine sandpaper or steel wool to give
your new paint something to hold on to. Just to be safe it might be better
to dull the surface of semi-gloss paint too, as I said, semi-gloss dulling
is a subject to be debated. As for the glossy paint (and maybe the
semi-gloss), the glossy surface is so smooth the paint has nothing to stick
to so it must be dulled!!! If the spray-paint is latex, which some today
are, you ARE back to square one. The latex paint will not stick to the
existing paint.
I worked in a paint store for over 2 years so I feel pretty confident of
my suggestions, but of course, nobody is perfect :)!
P.S. Regardless of anything, the existing paint must be COMPLETELY clean
to accept your new paint!!!
Corey Elliott
Amarillo, TX, USA
strmchsr@fia.net