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

[John Kelly]

Thanks guys! Here is my album page. It has several albums on shrinking discs:

http://allshops.org/cgi-bin/community/comm...d=9990093068868

If you going to torch shrink, heat only until the metal turns straw colored or maybe blue, not red. If the metal does turn red, do not quench, as it will get work-hardened. Heat small spots, let them cool (or quench, hammer and dolly the area to get smooth. Repeat as necessary. Not easy to do without making a mess.

Stay away from shrinking hammers. They make a lot of unnecessary marks, and don't work very well.

You might try a wornout sanding disc to heat the surface without removing much metal, then quench. Much more controlable than torch shrinking.

Here is an article that might help:

http://www.type2.com/library/body/wlsh.htm

Before shrinking, make sure that you actually need to. If you have done a lot of welding you have already shrunk the metal, and will need to stretch the weld area. Any pictures?

John www.ghiaspecialties.com