metal shapping advice needed, specifically how to shrink.. Options

[brant]

Hello all and John if your reading along today.
I've been doing some fender slicing and welding...
of course lots of pounding also...

specifically, I need some technique advice.
So I've got a spot that I want to shrink or tighten extra metal in.

I know John sells the shrinking disks which I'm considering, ... but in the interm, what is the old fashioned shrinking technique.

I know to heat the area with a torch.. but then do I cool it rapidly with water or something... or do I let it cool slowly to get the most shrink out of it?

hope this makes since
brant

[ArtechnikA]

I know to heat the area with a torch.. but then do I cool it rapidly with water or something... or do I let it cool slowly to get the most shrink out of it?

quench quickly to shrink.

the goal is to get the metal to contract before it has a chance to lose its plasticity from the heat. if it cools slowly, it will contract but it will not be permanent.

i don't know anything about the shrinking disks but i've heard about them - i'd love a pointer to further information.

there are also shrinking hammers and dollies that are covered with little pyramid points - like a ginger grater. i'd think these would work best on hot - or at least annealed - metal - but i don't have any first-hand experience in their use (although i do have a set in my bodywork toolbox...).

Ron Fournier's metalworking book is excellent ...