Colored pirmers

if a minitrucker wants to leave his ride in primer... for an extended period of time, don't sand down the stock paint all the way. leave some there. scuff it up and prime over it, that way the porosity of the primer won't trap the water on bare metal and rust it all out.

Sorry to sya,but by scuffing the surface of the stock paint, you are breaking down the film barrier and creating a porous surface again.....

It might resist rusting and corrosion longer, but it won't last.

but if you don't break thru the clear, just scuff it... does it still open up? you can cut and buff and it still resists moisture....

It does to a certain extent.....not 100 percent but it does comprimise the surface integrity of the clear a bit.