The Stovebolt Site Forums The Shop Area Paint and Body Shop Cab Back

Looking at the back of my 48 cab it is wavy and bent. I have a stud welder to pull out the dents but am unsure how it will look when this is done. Probably wavy still.

Any good tricks to get it smoother?

TIA

If it's wavy it's probably stretched so pulling one depression is just going to move the excess metal somewhere else and you're going to wind up with an oil can situation.

Shrinking metal with a torch and water or compressed air is amazingly effective and very simple. I had only seen it done once about 35 years ago but still had great success with the rear of my cab which was caved in pretty bad from years of having cargo slammed against it because the front of the bed was missing. PICTURE

My biggest mistake was not trusting myself and having a bodyman friend finish the job. He had never shrunk metal and just mudded it over. Although it came out well, I'm sure a couple more well-placed shrinks could have gotten it MUCH better.

Good luck!

Thanks Woody. This is what I have. I am going to try my best to pull out the dents then move on from there. I am sure it will be wavy.

I wasn't sure if anyone had used the shrink disc? Or whatever method to straighten this stretched metal.

I never heard/thought of the heat and water method

Never used a shrinking disk but I know a lot of guys swear by them. I'm sure that now that you've brought up the subject you'll get lots of conflicting opinions.

The torch method has been around forever, works very well, especially in a case like ours and doesn't require buying yet another tool... assuming you have an oxy/acetylene torch which is kind of a basic requirement if you're rebuilding an old vehicle.

Oddly enough, I was unable to find the torch method using a hammer and dolly on U-Tube but there are a few that do not use a dolly. I tried without a dolly and got no appreciable change.

There's also a reprint of an old auto body instruction book that describes the method very simply. Too bad you're not closer I'd like to have another crack at it on the back of a cab.

EDIT: The name of the book is Metal Bumping by Frank Sargent

Woody, does the metal shrinking method work on completely flat panels, even more specifically, aluminum flat panels? I have the same problem with the 860 I am working on. I believe the waves in my cab back are just from the pounding the truck over the years rolloing up and down the highway ( not actual dents).

Billy

some Utubes on heat shrinking [and one to the right about the shrinking disc]
and a bit about aluminum from here .... more here

Bill

I can't imagine why it wouldn't work on any steel panel that is stretched or oil-canned. Aluminum I don't think so but I may be wrong... I have no experience with aluminum car body parts.