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Discussion Starter #1
My son got a little crazy with the rotary wire brush removing the rustpits on the qtr panel under the trim panel on his BelAir. The moron who installed them used beads of adhesive slopped around the panel to hold it in place and everywhere a bead was water and dirt collected to make little rust pockets and pits.
Well, sonny boy wirebrushed the wires right off the brush, heated the panel and got a couple of puckers in what were perfect quarters. The puckers drop under the trim and look bad.
Advice on procedure, please! HK here's your chance!
 

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Pasadena, from all the other great posts I thought you would know this one!

Torch shrinking is most definatly something you'll want to practice before attempting it on a sweet peice of sheet metal. The basic idea of it is to heat the steel and cool it at a faster rate causing the steel particles to "shrink". Now in doing this some people use blocks of ice, frozen rags most anything cold will work. You just have to learn to use it. Now the torch part is the tricky part. Heating the metal at the precise spot of convexion is the key. Of course this will heat the rest of the steel as well so when cooling you have to pinpoint the spot you want to shrink and only that spot or you could very well have a huge disaster. Now, find the stretched spot of steel and only do one at a time, starting with the biggest first. Pinpont that spot with the hottest part of the flame untill the spot becomes red glowing hot. Be VERY[B/] careful not to burn through the steel, its very easy to do. Now when the spot is glowing the particle are spread farthest apart, by introducing something cold the particles with naturally "shrink" back together, depenedant upon the rate of cooling, the faster you cool, the more it will shrink, the slower it cools the less it will shrink. So of course by pinpointing the rate of cooling you reduce the chance of shrinking the metal inadvertantly around the spot your trying to shrink. Practice before you use it, its pretty tricky. Of course you could just result to a claw hammer and shrink the metal with two wacks, but thats just to easy for me.

I've seen guys heat a spot and use this giant rag and bucket and slop icewater on it to cool it. Let just say it wasn't pretty <img src="graemlins/drunk.gif" border="0" alt="[drunk]" />

Also for those of you with ready access to dry ice its a wonderful dent remover :D

HK
 

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Discussion Starter #3
Thanks, HK! The resorting to a claw hammer and two whacks sounds lots better than the fire wrench. Is there an easy way to explain this?
 

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Well the shrinking hammer, or the $2.95 claw hammer is pretty much just whack it(the high spot) a few times and the dimpling that the hammer makes with the spikes basically shrinks the metal through using the excess metal in a texture. The tenture is so fine that little filler is used in smoothing and sometimes its rarely needed if you sand the texture.

HK
 

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To shrink metal I use a #2 torch tip and set it up with a low neutral flame. Starting where you want to shrink heat up an area until its red and roughly the size of a dime then I quickly take a light body hammer with a small head or a small headed shrinking hammer and lightly tap the area then cool. I usually use a spray bottle of water to cool.After 2 or 3 shrinks I'll use a dolly and hammer to very carefully shape metal being very careful not stretch it again.
 

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watch out using water to cool down metal,it will make metal harder. try heating a small area and using dolly and hammer,allowing dolly to bounce freely
 
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