Originally Posted by Lizer
Yes, what I did was start at the front, then middle, then end, let them cool, then go place the next weld after the original first one. I thought I had read this method somewhere which is why I started doing it. Because--once again much like with my ORIGINAL filler sanding techniques in my other thread--I used to do my welds exactly as you described here, that is by splitting the difference. I never thought in a million years the way I had been doing it would cause what it did.
I figured the reason I got the warpage I did was because my metal didn't have enough of of a gap between the two panels at those spots (they were close).
Now, you're talking about shrinking the metal. I thought this entire time I should be stretching it because I shrunk it by welding it. If I'm understanding you correctly you're only talking about shrinking the peaks of the metal. Should this take care of the ripple as it extends farther down the quarter as well, or am I just SOL there?
I have a stud gun (which I use for shrinking), and I also have a 4.5" shrinking disc (which doesn't work well for me at all, but I think it's due to my angle grinder shaft having a slight wobble from an imbalanced wire wheel at one time). When I use the shrinking disc I'll notice that only one half of the disc is ever showing evidence from contact with the metal, probably due to the wobbly in my angle grinder, which means I'm not getting effective heat build up with the disc.
I purposely welded my hood filler panel in large increments straight thru, no skipping. First pic shows the welds and high and lows after hitting with a sanding board.
I then started working the welds, by grinding off the proud and stretching carefully.
If I overstretched, I used the shrinking disc. Stretching and shrinking were only used close to the weld as the material beyond the HAZ was neither shrunken or stretched from the welding.
Its not 100% yet but I'm pretty sure if I keep at it, it will be fine. I did it this way to learn about bringing overheated metal back from the dead.
Shrinkage is what distorts panels. The more heat applied the more shrinkage that occurs. The shrinking disc will be needed only after you over stretch that shrinkage when working it back.
BTW, your shrinking disc with only 1/2 contact will probably still work. Spray some water right after hitting with the disc. If it gives off steam, its still working.