Most exterior sheet metal was 19ga or about .042
18 ga is around .048
19 ga is hard to find many suppliers simply dont carry it.
If you go to a metal supply store ask to mic the sheet as tolerances can be all over the place. You might run into a piece of 18 ga that is pretty close to 19 ga in thickness.

Very rarely will you find sheet metal on the high end of the tolerance, I would try to buy 19 but 18 if not found...Eric


Currently working on custom metal and How to videos.

1949 and 1972 chevy trucks
70 chevelle SS455
Pictures of my work and projects
http://community.webshots.com/user/sevt_chevelle