Well, not exactly. I bought the sheet metal to MAKE a shrinking disc at Lowes. With all the recent posts on using one, I searched for more info. There were links on the Hamb about making your own out of 18 ga cold rolled. Lowes only had 16 ga, so I built the HD model. I used a standard 7" grinder rubber disc as a backer. After cutting the circle out, I rolled the edge, drilled the center hole, and releived,with a hammer form, the center hole so the nut wouldn't stick out. According the the articles I read, using one makes alot of noise, and I can confirm that.
Here's what I've learned. I anyone disagrees, please chime in. At first I was using it like I was removing paint, moving constantly over a wide area, and was disappointed with the results, or lack of. It wasn't creating any heat. I concentrated on a smaller area, like you would with torch shrinking, and stayed in that area for maybe 20-30 seconds at a fairly high speed, then quenched. The hamb said when you get steam from quenching, you're hot enough. I started to get results with this technique. The progress is fairly slow, you only get alittle shrinking each time, but apparently you can work the same area multiple times. Shrink, then metal work, repeat. After working two areas on a fender for about 45 minutes, one oil can and one walnut surface, both were much improved. The walnut surface in particular was old damage that was work hardened, and resisted hammer and dolly efforts. The disc removed alot of the roughness, the heat may have helped with the hardening, but I'm almost in bondo range now.
My conclusion is this works. A very useful technique along with good hammer and dolly work. I paid $13 for for the sheet metal, and I can make 3 discs from it, and I spent about an hour making one. I've seen prices of $40-$60 to purchase one, which is easier and probably better quality. Since I'm a cheapskate (or was it a tightwad, Bobby?) I'll stick with my home made disc.

 

It ain't rocket science -- it's steel-on-steel friction. I saw the HAMB article too and if I were inclined to do any more bodywork, I'd go your route. My only thoughts are that Lowe's steel (which I have used) seems to be high carbon, so it's going to harden quickly and I'd check for any sign of impending failure every so often.

Good job!

 

John Kelly posts regularly on the HAMB and on the MetalShapers forum...he will sell you a proper disk at a reasonable price. I bought one from him a couple of years ago and never regretted not trying to make it myself...then again I am not a tool maker but I like to use them.

 

Could anyone please forward links or URL's to HAMB and the MetalShapersForum? That sounds like good reading, and valuable education!

Many thanks, D.

 

Google will get you where you want to go...

 

Yes what he said. Please as I missed it and this Ham thing sounds intresting to say the least.

 

Man you are good. Ya answered my question while I was typing it. Oviously I need a voice to text program.

 

The HAMB stands for Hokey *** Message Board and is dedicated to traditional hot rods and customs. The folks on the HAMB are for the most part extremely talented when it comes to automobiles and metalwork in general. Much like this forum, there is a technical archive where you can find just about anything you want to know...kinda like havin' a few hundred John Niolons. Here's the link:
http://www.jalopyjournal.com/forum/

 

rhopper,
You're a man after my own heart!! Its nice to know I'm not the only tightwad around (got to save those extra pennys for frosty beverages....lol)

I recently read this article about making your own shrinking disc;
http://www.metalmeet.com/forum/forumdisplay.php?f=79

Bobby

 

I bought the professinal model of shrink disk from the CA manufacturer. It's over $200 with the kit and a video. He recommends running the disk after you have hammered and dollied as much as possible, leaving the area a little high. Run the disk on it until the metal turns blue. Then quench and repeat. After using it on and off for a year, I sold it for $100. The Sunchaser pro model is SS and has a waffle edge pattern. If you can get results with a disk made of normal steel, then Jag

 

I bought mine from a guy on ebay that makes them himself. Mine was <40.00 and is made from 14 or 16 ga smooth stainless steel and is 10" in diameter. I couldn't buy the piece of metal for that price, nor would I want to try shaping SS that thick. The grooves or texture in the expensive ones don't make it work any better (in fact may be a detriment, you do get a little galling and metal transfer to the disk, with the smooth disk you just touch it with a piece of 80 grit sandpaper while running to clean it off) just costs more. You have learned the technique, work an area ~ 6x6" in a Z pattern. If you have small highspots they may turn blue, but it doesn't need to get that hot to work. Once you have the major potion of the panel shrunk it will be very obvious where it is still low. A bullseye pick will make short work of raising up the low spots.