1946 Ford Pickup Stretched Sheetmetal Repair - Visit To The Shrink

With the lip straightened, the fender was flipped over and clamped to the steel table at each end, providing a more rigid structure to work with.

We opted to use a couple of different methods for shrinking the steel. Firstly, the old school way using oxyacetylene to heat an area about the size of a nickel until it glows orange. The metal will dome up but don't be alarmed.

It helps if you have someone to take the torch from you as you need to move quickly, backing the heated area with a flat dolly and hammering from the front, in a circular movement around the heated area, keeping the hammer face parallel to the metal but striking it at an angle, pushing it towards the center each time as shown by the arrows.

It helps if you have someone to take the torch from you as you need to move quickly, backing the heated area with a flat dolly and hammering from the front, in a circular movement around the heated area, keeping the hammer face parallel to the metal but striking it at an angle, pushing it towards the center each time as shown by the arrows.

Forcing the metal towards the center of the heated area with each hammer blow will shrink the metal, and repeating the process in the area where the metal is stretched will bring it into shape, removing any crown or domed area that existed where it shouldn't have. Here you can see where the hammer struck the steel around each heated area.

For illustration purposes (though it's also a useful visual aid while you're learning) we ran the sanding block over the area again to show the already improved differences between the high and low spots.

With the shrinking where required now complete, attention turned to working the high and low spots with a hammer and dolly. With easy access to both sides of the panel, as well as having it at a perfect working height, as opposed to being bolted to the car, this was relatively straightforward.

Wanting to get the metalwork as straight as possible and not just sling a load of body filler at it, I used a vixen file. Here's a shot of its aggressive and coarse blade. Not recommended for modern cars with thin sheetmetal as these remove a lot of material quickly!

Getting there! It's a case of hammer, dolly, file, repeat until you're happy with the result.

It could be better with more time spent on it, but that was one thing I was short of, and seeing as the fender will need filler anyway-specifically to blend the join where the F-1 section was welded to the F-100 fender-this is good enough, and way better than what I started with.

Here's another way to shrink steel. Almost like a single-sided spot welder, this machine creates an electric arc to heat a small spot, which in turn shrinks it. The area inside the circle is a high spot.

As you can see, the circled area shrunk, a little too much, and now I'm working on high spots on either side of it. This is only for illustration purposes; I would normally work the area with a hammer and dolly first.