View Full Version : oil canning in 16 gauge steel


Doc Dave
07-20-2007, 09:29 PM
I am metal finishing the bed sides on my 1952 Power Wagon. They are 16 gauge. Everything is going well with the welding of new metal in, etc, but on both sides there are areas about 6" diameter with an oil can. It is not dramatic in its movement due, I think, to the steel's gauge, but you can feel it when you run your hand over it.
One reference I saw said to push the low spot out to level from behind, then use a body hammer around the perimeter of the other side. Another reference book, "the key to metal bumping" talks about using heat and a hammer.
What would be best here, and does the thickness of the steel a factor in how you approach it?

07-21-2007, 07:11 AM
I would shrink the area with a stud gun. Len sells shrinking tips, but the regular tip works fine for me

John Kelly
07-21-2007, 09:51 AM
If the bed sides were fine before the welding, you need to stretch the welds. This does not sound like an oil can? If it is a shallow wave that does not pop in and out when touched it is simply a low spot or series of low spots. Stretching and smoothing, and perhaps a little shrinking towards the end of the process should get it. Any pictures?

John www.ghiaspecialties.com

Doc Dave
07-21-2007, 08:38 PM
The 2 areas with the "oil can" are not near any place where there was welding.
I need to post some pictures, I know, but they are up on a flat section of the bed side near the top.

Doc Dave
07-21-2007, 08:39 PM
I would shrink the area with a stud gun. Len sells shrinking tips, but the regular tip works fine for me
88, can you briefly describe the process? Does the heat of the stud gun, and pulling with the tool, permanently bring the "dent" out?

07-21-2007, 11:39 PM
There are two approaches I would take to solve the oil canning. First I would see if driving the metal around the problem toward the center would help stiffen the metal. I would do this by holding a 2X4 along the peak above or below the problem and hitting the peak toward the oil can to stiffen it. If this doesn't work quickly I would not keep trying because you don't want to damage the metal any more than it is.

Secondly I would use my stud welder with the shrink tip. The shrink tip will heat an area about the size of a pencil eraser so I put it in the middle of the problem and pull the trigger for a couple seconds until the metal gets red hot then release the trigger but continue to hold the gun against the metal for a couple more seconds. This will pull the metal together in that spot then move the tip over about an inch and do it again then make a circle around that center point and enlarge the circle as you zap each spot. This should stabilize the metal and allow you to finish the repair without further oil canning.

John Kelly
07-22-2007, 09:51 AM
It sounds like the weld has shrunk and may be pulling on the surrounding metal creating warps. How far away is the welding from the oilcan? A weld can pull all the way across a flat panel. Was that metal straight before you welded?

John www.ghiaspecialties.com