How to raise fender edge?

[jtfx6552]

I welded a welding rod on the back edge of my fender to fix a gap.

Evidently the heat of welding caused the edge to shrink and pull in. How do I raise it back up without the hammer or dolly dinging up the folded over edge?

 

[Dean Jenkins]

Have you test fit it after doing the welding? Did you make that same measurement before welding?
Reason for the questions is that many classics have a "crown" on the fender/door/quarters, and they sort of dip in as the panels come together.
Tri-fives are kind of extreme examples.
Here is a picture down the side of a 57. Look carefully how the panels are not a flat plane, but are crowned in the middle and come in at the gaps.

 

[Chris_Hamilton]

I welded a welding rod on the back edge of my fender to fix a gap.

Evidently the heat of welding caused the edge to shrink and pull in. How do I raise it back up without the hammer or dolly dinging up the folded over edge?

Not really knowing exactly what you did I'll give you some general info.
If it shrunk from welding the edge will need to be stretched. Get a dolly that matches the contour of the surface, and a body hammer. hold the dolly flat and tight against the underside and start evenly hammering from the top. All along the area that is low. Start where you welded or as close to it as you can. Work that area first. Check your progress. As it starts to come up work outward.

 

[Chris_Hamilton]

If you are doing it right the dolly will ring as you hit it. That sound means you are stretching.

 

[MJM]

Take what I say with a grain of salt but, if I did not want to mare up the backside of the door skin fold, I'd bend a piece of 1/16" x 3/4" or 1" steel to the shape of the door. Then clamp that piece to the back of the door. With a dolly on the front of the door skin, I'd hammer the lip from the backside towards the dolly. Remember, lite taps go a long way.

Good job by the way welding up the edge. I can't tell it was done.

 

[theastronaut]

Hammer on dolly along the edge, be precise with the hammer/dolly alignment to make it ring and stretch like Chris said. If you only hammer the edge outward without stretching it'll develop a low spot just inward of the hemmed edge.

Most old cars have panels that dive inward at the ends. Some are worse than others, the mid 60's C10s are the worst I've seen; the front edge of the door is really rounded inward. Welding the edge makes it worse from shrinkage.

This edge curled noticeably when I welded 1/8" rod to it, but a few controlled rounds of on-dolly hammering stretched it back flush with the rest of the panel without creating a low spot next to the hem. It's best to stretch the welds before they're fully ground down so all of the force of the hammer/dolly goes into stretching the weld.