Squeezing a flat panel while working with a beating panel is unfortunately a dying art. More and more often, these days panels are usually replaced rather than repaired, but there are many old cars for which replaceable panels are no longer available, this is when this practice is useful. You will need some basic knowledge about the beating of the panel, as well as some basic tools for beating the panel, and an assistant is very useful for this operation.
Let's just say that we have a door panel that is stretched, this is a fairly common problem with doors, since they have fairly large flat areas that stretch quite easily during a delay. You would remove the door as soon as possible and support it horizontally, at a comfortable working height, where you could sit at the door and go inside with one hand holding the cart and reach the top side with a hammer. The first step would be to sand all the paint over the entire damaged area using a sanding disc with 24 sands on a 4-inch sanding machine. Then determine the center of the stretched part by pressing with one finger and seeing where the “weakest” part of the panel is located. Once this has been determined, you need to circle the area with an asbestos circle, if this is not possible, you can use a damp cloth, the circle should be about 3 inches in diameter, then you need (and not a cutter that is too hot) with a conventional welding flame not too oxidizing, it places the flame approximately half an inch from the panel in the very center of the stretched spot, right in the center of your asbestos / wet cloth putty. As soon as the metal is cherry-red (the faster, the better) take out the torch and pass it on to your assistant. The hot part is the center, you should hit h ammer with shrinkage (over the panel) on the shrink cart (under dad nel) in the form of a circular motion inwards, as if you were trying to send everything that was outside the hot spot to its center.
This pushes small parts of the metal towards each other and causes them to “take up less space” and thus tighten the stretched area. The whole beating procedure should be carried out as quickly as possible while the hot spot is still hot, and then it must be quenched with a damp cloth and cold water. It is necessary to ensure that the zone is not too hot, which could cause it even more. When you're done, you need to check if any more compressed spots are needed, it can often take two or three to fix the problem, but if you do it right, you will immediately notice the difference. Sometimes I had to use up to fourteen heat shrink spots to fix a very stretched panel, so go. Perhaps first try it on the scrap panel before trying to correct your pride and joy!
