Touch up paint is usually good old cellulose, and the reason they don't use it on exteriors is beause it is poor (no chemical resistance, poor gloss, poor weather resistance) but it does dry very fast. Usually applied by artist brush and most specs don't recommend it for anything bigger than chips of approx. 1 - 2 mm.
If the repairs are carried out in a controlled enviroment then they are probably using 2 pack polyurethane, but I doubt they would be using this in the main paint shop as the unions don't allow it on health and safety grounds.
Of course it could be that they use a combination of repair systems. |