TR2/3/3A gas tank hole body work

[sp53]

So, I am working in the area of the gas tank hole and trying to get the area flattened out for putty. I cannot seem to get the area to be a low spot with my hammers and dolly; the high spot moves. The PO evidently pulled up and around as he tried to get that big bolt off the filler. Any ideas would help

 

[mixdenny]

You will need to shrink that spot. There are several different methods. For one small spot try heating it with your smallest torch tip and immediately quenching it with a wet rag. You may have to dolly around the spot when it is hot, then quench. You can search for shrinking and find various web sites on metal working. Dennis

 

[TomMull]

Dennis has the right idea but I would work on the dings first. Heat each one and hammer from the high side, underneath as it appears in the pictures. It might be easier to have a helper heat the peaks cherry red while you hammer from underneath. You could have your helper lay a flat dolly on top too. Use several light blows, about like putting a tack into softwood. You'll only get a few taps before the peak cools. Avoid heating the same spot more than a couple of times. Flattening the dings might help with the bulge on the other side too, and the heat/ quench method above should finish it up.
Tom

 

[CJD]

As they say above, shrinking is the book answer.

If you don't have a torch, you should be able to "oil can" the high into a low, so the tank will sit flat. You'll have to back the area when you hit it to "can" it the other way.

 

[sp53]

I probably was not clear; this area is the top where the gas cap goes. I have good access, but the problem I am having is the large hole used for the gas cap has made the area around the hole flimsy and the more I try and hammer dolly the ripple spreads. Perhaps I am expecting too much. I did have some success with the dolly and hammer, but I wanted it flat, but again the area is wavy from the weakness of the hole; it probably should have had a fold over in the hole to make it stronger. I might try skimming the area by starting back a few inches with glaze compound and feather towards and up at the cap hole. The cap should hide the slight lift in height.
The PO probably fought that nut; I have fought a couple there too.

 

[PatGalvin]

The previous stresses on the area around the hole stretched the metal. The more you hit it, the worse it will get. First read the surface of the metal and estimate where it has stretched. Then you can shrink by applying heat to one small area at a time and then applying hammer and dolly while it cools. When you see the metal shrink and the flimsy oil can tighten up, you will be amazed. After you shrink a couple small areas, read the metal again. You can over shrink an area and create a new problem. Suggest you pick up a piece of 18 or 20 gauge sheet steel, create a stretch with a hammer, and practice with hammer and dolly. You can also shrink with heat and a wet rag or heat and compressed air. Bondo or glazing putty are not a substitute for the needed metal work. Especially on a flat-ish area like the gas tank hole area.

 

[tdskip]

Great advice here...

 

[Brinkerhoff]

Lots of good advice, shrinking is the answer. I'd start with three small spots equally spaced around the hole right at the edge. Heat / quench then wait for the metal to cool to room temp. before I'd go further.