I think the tool Jerry's referring to is a panel joggler,but i've had bad experiences with overlapped joints,it provides a water/rust trap if not fully sealed afterwards.IMO.

I much prefer to butt join and work the weld although i'm not sure how Chip and the gang managed to do butt joints with Clecos.

These are much more suited to butt welding joins and hold the panels with just enough gap for maximum weld penetration.
This is a UK based site but i'm sure they're available your side of the pond.

Last edited by jockbolter50; 11/28/2014 12:11 PM.
1950 Chevy Advance Design 3100 in Scotland
In the Stovebolt Gallery
More pix on Flickr.
I've definately got this truck thing in my blood ... my DNA sequence has torque settings
"Of all the small nations of this earth,perhaps only the ancient Greeks surpass the Scots in their contribution to mankind" Winston Churchill.