Shrinking Disk, Useful?

[Stanger]

Does a stainless shrinking disk work? I have oil canning spots on my Mustang and need to shrink the areas. I tried to work them with a hammer and dolly but no dice, it just pops in and out. So will a shrinking disk solve my problems(assuming I use it properly)?

[Phil V]

Which panels and what part of those panels are oil canning ? (the odds are you don't need to shrink the metal).

[John Kelly]

The shrinking disc is the best tool in a metal finisher's arsenal. If you only have one area to work, make your own out of a stainless cook pan lid. If you plan to do more body work in the future get a fabricated one. I make them and so do others. Mine is $35 delivered. There is no tool that shows you what the panel needs faster than a shrinking disc. It will tighten up a floppy messed up area in short order so that you can read it to see what to do (more shrinking, light stretching, smoothing, or bumping).

If you do a search using oilcan or oil can you will probably come up with a lot of good information.

John www.ghiaspecialties.com

[Mooch]

I agree with John. Went almost my entire life to this point without one.

Oh boy what a mistake that was. When you need it for the money there is no better buy than the shrinking disc. I just wish i had bought one when i was doing much more body work.

Buy it and use it . Also buy some of the low cost slapping spoons from Len.

Buy the Video also as it really shows you how to use one. Mooch :)

[Lost in NJ]

Will the shinking disk work?

A good question.

The problem could be from too much shrinking or shrinkage from damage. So the real fix would be expanding the metal.

Tear into the side of a piece of paper about 1".

Then ever so slightly overlap the tear.

Now you have an oil can point, how do you fix it?

The problem is the edge is too short. If you shrink the bump you still have an edge too short.

Remember every weld is a shrink point, no matter how small the weld. Actually any place you heat metal up to where it will turn blue you can run in to a shrink point. The effects of a weld might be on the opposite side of the car depending on the structure.

For what it is worth, I have a shrinking and disk and have found it very useful. I am just learning all of its uses and have found it does wonders for leveling metal.

One last note, be real sure before you shrink some metal. You can do more damage than you might ever imagine if you do not know what you are doing. Always shrink a little and wait for the whole panel to cool down before deciding to shrink more. I learned this the hard way.

[Stanger]

Thanks for all of the replies.

Which panels and what part of those panels are oil canning ? (the odds are you don't need to shrink the metal).
I have two panels. The pass. door and the driver's quarter. The door has two large dents that I removed from the inside with a wedge of wood. The dents were in the top bodyline of the C on a '66 Mustang. Here is a picture.
http://img377.imageshack.us/img377/222/dscf00441tb.th.jpg (http://img377.imageshack.us/my.php?image=dscf00441tb.jpg)
I worked the bodyline back out to normal with the use of a straight edge. I then dealt with the dents above the bodyline. I worked these out and all was well. Yesterday I was preparing to apply some filler on the door and was checking for any high spots. Sure enough, there was a raised 'brow around the 2nd dent. I worked the 'brow back down but then I had an oil canning issue. This particular spot bounces back when you pop it in whereas the other does not. I assumed that by attempting to bring the 'brow back in, I presented to much material for the given area. I assume that the 'brow was a relief for the stretched metal, is this correct, or not? The other spot is on the quarter panel. I replaced part of it with a half patch. I used someone else's welder and it was running straight Co2, a hotter weld than argon/Co2. This caused some warpage toward the rear of the panel. I tried to work down a high spot on it as well and now have an oil canning issue where the metal EASILY pops in and out. This spot does not bounce back as the other does. So does a shrinking disk sound like it would help? Thanks alot guys. John Kelly, I would be very interested in the disk you offer, could you post a picture?

[Phil V]

Stanger, sounds to me like a shrinking disc would work well for the heat warped metal/oil can effect in the quarter panel. My guess is that the door oil can should be worked out with shrinking any metal. At some point around the previous damage on the door there is a high spot. Carefully tap that high spot down and your oil can effect will disappear.

The picture you posted didn't work. It would help if I could see a picture.

[Phil V]

The picture in your previous post is working now. It looks to me like the lower bodyline is pushed in some at the damaged area.

[Stanger]

Thanks for the help Phil. I will add another picture of the door. It probably won't help though as it is a head on shot. I worked the body line alot with a wedge shaped piece of wood from inside, and the straight edge tells me that it is within less than 1/16 of an inch. I plan to leave it that way since I need to apply filler around that area anyway and thought it might be easier to blend if it was just a tad low(barely any). This section of the door was oil canning when I bought the car but after some work it was gone. Then I was trying to work the high spots in preparation for filler, and the more I worked, the worse the oil can became. Obviously I can't just leave the high spots, but working them down doesn't seem to be working as you suggested. Should I try again, or am I missing something?
http://img354.imageshack.us/img354/52/dscf00435uv.th.jpg (http://img354.imageshack.us/my.php?image=dscf00435uv.jpg)
Here is the same pic as before but with the bodyline accented in red, the dents circled in red, and the high spots circled in blue. May not help at all but...
http://img45.imageshack.us/img45/849/editeddoorpic6cv.th.jpg (http://img45.imageshack.us/my.php?image=editeddoorpic6cv.jpg)

[Len]

You can make your pictures larger than 9K. This forum will accept up to 39K pictures.

[John Kelly]

Hi Stanger,

I would not leave any portion of the panel low on purpose. It will make your oilcan situation difficult to fix properly. It looks like you need to push out on the low areas with a dolly and slap or hammer on the high spots to try and level things out. Oilcans happen when there are not even tensions in the contours of the metal in all directions. This means picking up low spots and shrinking high spots, and smoothing the ripples or waves. Here is a link to my shrinking disc album:

http://allshops.org/cgi-bin/community/communityalbums.cgi?action=openalbum&albumid=9980121727059

John www.ghiaspecialties.com

[Stanger]

Thanks for the advice, I will bring those spots up to level, or a little high. I will then shrink them with the disk, sound good? So $35 for the shrinking disk with the safety edge? How do you want your payment, do you accept PayPal? Thanks alot. Oh, by the way, could you explain the slapping spoons to me. I know it is probably a stupid question, but I only know what metalwork I have taught myself and am in the dark on some of these methods/tools.

Edit: Thanks Len, I will post larger pictures in the future. Ok, I made those other pictures larger. Maybe now you guys can get a better view. These pictures are above 200k, but they're thumbnails, is that OK, Len?

[John Kelly]

Hi Stanger,

The $35 delivered is for my low crown disc...no safety edge. I hardly ever sell the flat one with the safety edge anymore. The most dangerous time with a shrinking disc is when you pull it off the panel while it is still spinning like some folks do. Do not take the disc off the work until it is stopped! I accept paypal using my email address: ghiafab@coastaccess.com

A slapper is like a hammer with a larger face to cover more area with each hit. Ron Covell at: www.covell.biz sells a really nice one. Get the heavier one for steel, or make your own from an old leaf spring or a piece of flat bar. He calls it a slap hammer I think.

A spoon is a slightly different animal...usually not heavy enough, or shaped right for much slapping.

John www.ghiaspecialties.com

[Stanger]

Thanks for the information. So your saying that I really don't need the safety edge? What are the pros and cons of a high crown disk to a low crown disk to the flat one? I guess I don't understand why so many are made. Thanks for explaining the slap hammer. I think I mixed the wooden spoons for leading(is this right?) with the slap hammer somehow. Once I learn a little more about these shrinkers I will order one from you. Thanks