Thanks, The Eastwood clamps I use for fitment only, to get the joint close. Once the gaps were non-existent, I used c-clamp vise grips to hold the two panels together tightly, in about three different spots, and tacked them together. Typically you will have to planish some of the tacks before you get them all done, as the shrinking pulls the panels together too tightly where they try to overlap. A couple strikes on the last weld with the hammer and dolly usually spreads it back to flush again.