Ptc, Thank you. I alway butt weld my panel in. I never do an overlap because the metal is too thick to hammer and dolly and it also gives the moisture a place to hid and rust between the seam. The glue bit is an inside joke between my buddy Trently (aussie54) , we use that instead of welding joking around. There are some good glue but that take an overlap seam to use it. The stuff is very strong though.
The shrinking disc I use is a 9 inch wheel that I just keep on theat Craftsman grinder. I weld my panels the grind them. If I can get to the backside I grind it too. I then hammer and dolly the panel to take amy warping. Like I said I grind both side because I have a good set of hammer and dollies from dagger tools and I like to keep them nice. So no hammering on bumpy welds. Then I run the shrinking disc over it. It will only heat up the high spots and the spray it with water out of a squirt bottle and it shrinks the high spots. It works really well. I bought it from Wray Schelin I think off flea bay a few years ago. I have a 4 and 9 inch one and it came with a video too. His website is
www.proshaper.com.
If you ever have any questions that you think I can help with give me a shout. Be glad to help.
Shannon