So Ive got this cab to my Chevy truck, where the small back window area has some pretty bad oil canning. I have worked it with a shrinking disc and gotten it to lessen, but I have a huge crown coming up in the center, as shown in the picture, with a good sized low at the bottom and top. These oil cans do pop in, but do not stay in and will pop back out. Now the issue I am having repairing this is also the fact that I cannot access the back side easily with a dolly or hammer, so I am really stuck with doing any repairs externally. I am concerned moving forward the only repair would be to cut and weld in a new panel, but want to see how everyone is thinking at this time.
Something I have learned several times over the years. An Oil Can is just the effect of damage or pressure coming from somewhere close by. Find that spot and repair it and the Oil Can often goes away by itself. I never work the spot you are dealing with. Proper reading of the overall panel is a must do first.
I'm also a fan of carefully removing the inner structure blocking access...complete the external repair and then re-welding the inner structure back in place.
See, normally that would not bother me, but this panel flows into the inner roof and entire back window. Not only that, it would require removal of the outer skin, and at that point I would just do an entire replacement.
No damage is evident at this time, I have searched high and low on this panel and cant find much aside from very small dings, which have now been fixed. I am wondering if it was honestly close to this from the factory and I just made it worse.
A good friend of mine (R.I.P., Morris) showed me a perfect '50 Ford F1 he and his bro found in Fresno, an actual 'Barn Find'. The farmer had bought it NEW, drove it on the farm for a week, when it ran out of gas. (!) When he put gas in it, the fuel pump apparently never picked it up, so it wouldn't re-start. He pushed it in the barn and bought a Chevrolet A.D, 1 year old. Chevy never failed him. Morris asked if the Ford was for sale...(less than 30 miles on odo) Farmer said, "Oh, I'll sell it...But you wouldn't want to pay the price!" Morris paid his asking price, the cost the farmer paid when it was new... Point is, when Morris and his bro (excellent bodyman) stripped the paint down, the doors, cab back, top...were wrinkled as a washboard! I asked "How, why?" "They were TRUCKS! To be used for trucks. Didn't have to be like cars...Trucks!" Morris and his bro worked on the body for months, then primer, then BLACK Nitro cellulose lacquer. Tommy the Greek did an apple green beltline on it, stand back and look...it was like a mirror. But "TRUCK=Months." Never forgot that. My '55 F100's straight, (I'm 2nd owner...Older ones were worse. I also have a '51 F1, it is 'wavy'...)
I wouldn’t be too scared to try a torch shrink right on the high spot. Make it light, quick, and use gentle taps. Might not be perfectly smooth when done but I bet the oil can will be gone.
AD cab in my shop. Looking at the small pics on my phone I guess this is what you’re working on if you’ve ever done or watched paint less dent repair then ya know an access hole is sometimes needed. A strategic hole and a pic could help the area.(possible hole location to reach the outer panel, yellow arrows) The other option would be a stud gun. Working a boxed panel can be fun. Using a shrink disc on an area that doesn’t have access from behind can cause issues. The shrink disc method generally utilized hammering/working from the back side to raise metal then use the shrink disc to level high spots. Repeat the process on the remaining low areas. So it’s kinda like a dance between stretching and shrinking to level the panel. Its possible the oil can is created or worsened by over shrinking.
I think that is the key, before, during and finished. Being good at it is somewhere beyond***** and Jane.
I'd like to give Anthony's post #10 5 likes being it's spot on but we are limited to just 1 per post. Oil Cans are the Devil until you figure it out. Most home builders go Krazzy on the Result because they don't know the Cause.