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Old July 31st, 2006, 08:28 PM   #5
John Kelly
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Join Date: Dec 2002
Location: Gullwing Inn, Moclips WA... the very edge of the civilized world
Posts: 386
Default Re: oil canning

Something I wrote a few years go on another forum...just want to add that you should check the whole panel for low spots starting at the perimeter and working in...What helped me work with oil canned panels is to think about the tension in the plane of the metal. The crown a panel has puts just the right amount of tension in it to hold it in place without being so floppy as to pop in and out. Try pushing in on various spots around the perimeter of the area with your thumb while popping the oil can in and out. Once you find a spot that helps stop the oil can popping, check this small area for smoothness. You may need to hammer and dolly to get it back to a smooth but slightly high condition, then shrink to get the tension just right. There may be several areas that need this attention. It is easy to overlook a spot that is affecting the panel and spend too much time playing with the oil can itself. You can also try pushing out instead of in at various spots on the panel to see the effect on the oil can. If you are going to use a torch to shrink, try heating the metal to blue instead of red. It will shrink with very little or no hammering, and stay a bit more workable than metal that is heated to red. A shrinking disc is the best way to shrink an over-stretched panel because it heats just the high spots without over-heating them. You can stretch with the hammer and dolly and shrink with the disc many times without damage to your panel until you get it right. This allows you to free yourself from worrying about over use of the hammer and dolly which can keep you from getting the job done.

Oil cans can be very tricky. I recently spent about 7-8 hours fixing one on a quarter panel that I had flared. All the stretching of the fender had resulted in a different pull and tension in the panel, as well as a reverse curve that was not part of the original quarter panel. I ended up shrinking metal that had not been stretched to remove a large bow that inhibited the reverse I wanted, stretching various areas around the oil can, and pounding from inside the quarter panel against the inside of the door opening flange just a little for tension in the plane of the metal. The bow actually shrunk down 3/16" measured in the middle of a 20" verticle template of the curve before I started. I learned a few things on this panel that made it well worth the effort. Hope this makes some sense!

John www.ghiaspecialties.com
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