Shrinking Disc

More of an art than a science - discuss metalworking and welding here.



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PostPosted: Sat Apr 01, 2023 10:50 am
Hi guys. Just been watching a lot of videos about this shrinking disc system. Seems to work well if you have the knack for it. I'm looking for ways to manipulate those small little dents or divets that I can't seem to hammer out. Do many of you use this method or is there another or better way? I've been on the fence about it but sure thinking of upping my level of metal finishing with this tool. I'm really enjoying the art of metal finishing these days. Too bad I'm not getting better at it lol. :rolleyes:

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PostPosted: Sat Apr 01, 2023 2:50 pm
I am not an expert by any means but I do use a shrinking disc.

Too many self proclaimed "experts" putting out videos these days for my liking. That being said, I was advised by a pro to get the metal working DVD by Peter Tommasini. Can't say whether he is the best or not but it was easy to follow.

Yesterday I used a shrinking disc on an area of my '68 GTX trunk lid that was oil canning.
The disc contacts only the high spots in the metal and the trick is to get the metal hot enough that it shrinks when cooled. I use compressed air to cool the metal.
1968 Coronet R/T


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PostPosted: Sun Apr 02, 2023 10:01 am
Does air work better than water for quenching? It would be a lot cleaner, less messy I guess. Take the rust contamination out of it.



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PostPosted: Mon Apr 03, 2023 5:52 am
Shrinking discs work great on the things they are supposed to! Just be sure your area is stretched, and needs shrinking! I've seen guys use them on weld seams (which are shrunk, and need stretching). Wray Schelin's tip for them, is to use a black marker all over the area you are using the disc on. Helps lubricate the area, and give you a visual of what's going on.
As for minor dings and dents, a slapper and dolly work best on them. When starting out, it's probably better to use a slapper file, not a smooth one. as you will be able to see your progress. You can put a dolly behind a ding, and use the slapper on it, and the dolly will raise the ding up and flatten it in no time.



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PostPosted: Mon Apr 03, 2023 8:01 pm
jimmystoys wrote:Does air work better than water for quenching? It would be a lot cleaner, less messy I guess. Take the rust contamination out of it.


NO! use Damp wet rag, Not soaked not dripping just wet damp and cold if possible.
The idea is to cool the panel. Do not over heat the panel either!
Dennis B.
A&P Mechanic, FCC General radio Telephone Operator
Line Maintenance A&P Mechanic and MOC Tech specialist.



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PostPosted: Mon Apr 03, 2023 8:07 pm
chopolds wrote:Shrinking discs work great on the things they are supposed to! Just be sure your area is stretched, and needs shrinking! I've seen guys use them on weld seams (which are shrunk, and need stretching). Wray Schelin's tip for them, is to use a black marker all over the area you are using the disc on. Helps lubricate the area, and give you a visual of what's going on.
As for minor dings and dents, a slapper and dolly work best on them. When starting out, it's probably better to use a slapper file, not a smooth one. as you will be able to see your progress. You can put a dolly behind a ding, and use the slapper on it, and the dolly will raise the ding up and flatten it in no time.



:goodjob:
Dennis B.
A&P Mechanic, FCC General radio Telephone Operator
Line Maintenance A&P Mechanic and MOC Tech specialist.



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PostPosted: Wed Apr 05, 2023 11:17 pm
Thanks for your input guys. Now I just have to order one!

Just wanted to add...I do use a slapper. Works well too.

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