Posted by chriscase on Wednesday, December 14, 2005 at 11:43AM :
In Reply to: Re: Reinforcing the Roof posted by Northern Calif Dave on Tuesday, December 13, 2005 at 6:26PM :
Use an acetylene torch, heat a spot the size of a dime til it's red hot, let it cool by itself. Don't cool it quickly, that will make it hard. Skip around a bit, don't let one area get tooo hot. It won't take much to prevent an oil-can.
The 'shrinking' effect is done while it is getting heated. As the metal expands, the encapsulation by the surrounding material makes it pile up while soft. It cools, and does not want to spread back out.
When doing body work, DO NOT pound directly on the dolly. It will act as an anvil, and you will spread the metal out, I.E, stretch it.
I've read about the shrinking discs, havent used one. They are just a disc of 1/8 stainless. I guess they cause some heat, and suble vibrations to push the metal back in?