welding technique

[Dreamcar]

Hi. I few years ago on another project, I made a rookie error by welding a patch panel with a mig and flanging method and it was too far away from a natural panel line. Once the sun came out, I could see a ghost or shadow line once the car was painted. My internet research seems to indicate that because the mig is harder, in contracts at a different rate than the surrounding metal when it heats up under the sun you see a shadow line.

So last night, I was watching an instructional video and they were replacing a quarter panel skin. They created a flange about a half-inch under a natural panel line and mig welded the seam. My question is...how far away from a natural panel line can I go so I don't see that ghost or shadow line. have any of you had this problem?

[areibel]

I haven't seen a ghost line with a welded panel, but I have seen it with a panel mounted with Fusor.  What kind of filler did you use over the weld?   I've been tempted to do a panel with Fusor but I think  you'd need something like All Metal for the first coat of filler.  Maybe that would help with your issue?

[Dreamcar]

First, that particular car is long gone now, but I'm jst trying to avoid it on my current project once panel replacement time comes. I had use regular filler, so maybe that was my issue. Maybe all metal or duraglass would have been a better choice.