Shrinking involves heating and rapidly cooling small areas of the metal where it's been stretched. Formed sheet metal has a "memory"- - - -it wants to go back to its original shape. That's impossible if the metal has been stretched beyond its elastic limits. Start by getting the panel back pretty close to its original shape with a hammer and dolly, working from the outside of the dented area toward the center. Don't overwork it- - -the more you hammer, the bigger the stretched area will get.

Once you identify the area that needs to shrink start heating dime-sized areas red hot, then quench it rapidly with a water-soaked rag. If the metal erupts into a pimple-shape where it's been heated, quickly use a hammer and dolly to flatten the bump, then quench. As the metal shrinks, the panel will get stiffer, with less "oil-can" effect where the metal pops up and down past the desired shape. Metal-finish the panel by scuff-sanding the area with a flat plane-type sanding board or a quick swipe with a rotary sander, and identifying high and low spots that need further work. Good luck!
Jerry

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