Originally Posted by The Greek
18 gauge for body skin? Are you building a Mustang or a Hummer?
:nogrinner:nogrinnerHummer:nogrinner:nogrinner Thats funny, I like it.
Although a novice, I have found 20 ga to be a bit thinner (by a few thousandths) than most skin and 18 ga just a bit thicker. Exterior skin is probably closer to 20 ga and floor pans are probably closer to 18 ga. The 20 is certainly easier to fabricate with. By the time the welds are ground, and the metal bumping, shrinking and streaching are complete, the patch seems to metal finish a little better with the 18 ga. I welded in almost a full 4'X8' sheet of 20 ga on my Nova with all the modifications and had no problem metal finishing it so it is really a mater of preference in my opinion. But 18 ga is not too thick for exterior skin and probably easier to weld with a flux core machine and/or limited experiance.
18 ga side marker shave tacked
18 ga side marker shaved finished
20 ga factory wheel tub sectioned 5-1/2"