Thread: Oil Canning??.

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Explain the term Oil Canning in terms of metal work??.

ask my buddy l call him bone head..... i can give you his number he can tell you how to piss McCarthy off ..... he would over work the metal then call me up ask me to strink it back down he always did it on the old chevy box sides by wheel opening . some time i could kink it back for if he did not go all out nuts .....if your over work the metal gets stetch out ...OIL CAN..... pops in and out like the bottom of a old oil can ...click ..click when you push on it then it needs to be locked back in so the panel will stay in form

Remember how an oil can when pressed will pop back. Body panels where the metal is stretched will demonstrate the same pop back that an oil can does, aka oil canning. To fix this one needs to shrink the area so that the panel will lay flat. True body men will shrink the area with heat and cold, there is a shrinker disk I have read about never used. For me I put some cuts in the stretched area to remove some metal and then stitched it back and smoothed it. That may or may not be the proper way but it worked.

i shrink with heat . cold . done it many time over the years best thing is not to over work the steel but some times when thing get hit bent up it happens . i use shrinking hammer .spoons . worn out sanding dics with a wet rag will work. kinking as well . tourch . spot welder all will shrink

Hammer and dolly on the weld??.

Check this article out - while not "automotive specific" it sure details the reason for and how to deal with "Oil canning".

Preventing oil canning problems - Tool and Die Tech Cell - TheFabricator.com

Originally Posted by 1gary

Hammer and dolly on the weld??.

Gary, when you weld on sheet metal it shrinks,you hammer and dolly on the weld to put a little stretch back in it and to planish it (smooth it), before you grind the weld down. Do not create too much heat with the grinding or you shrink it again. Example take two pieces of say 20 gauge, fit the edges together and make a couple tacks on one end,this creates a shrink @ the welds and you'll notice the other end opens up the gap. Simply planish the spot welds (stretch) and the gaps will close back up on the other end. Metalmeet.com plus Youtube has a wealth of information

Gary, there are two kinds of oil canning, a loose oil can caused by shrinking (usually a result of welding) and a tension oil can where a dent or glancing crease causes a stretch, pushing tension into adjacent areas of the panel that may result in a bulge that can be pushed back and forth, only this time, requiring a bit more force than the loose oil can. Given one is caused by a stretch and the other by a shrink, the repair depends on the cause.


If yours was caused by welding, then you should have a loose oil can, fixed as indicated above. Try to keep from introducing any more heat in whatever repair method you use at this point, as that may shink more.