Once had something that sounds similar to this. I spray painted outside with matt black aerosols. Car came out with patchy white areas, Was told it occured due to moisture in the air (it was fairly damp). Ended up going over it again.
A forum community dedicated to UK Hot Rod & Street Rod owners and enthusiasts. Come join the discussion about Hot Rods, builds, performance, modifications, classifieds, troubleshooting, maintenance, and more!