1/4 panel stretched how to fix

So had the car media blasted and 1 quarter panel must of taken too much heat. And now pops in and out by touching it. What's some ways to fix this???

Research shrinking disc.

I have seen a couple ways done by someone with 30 years exp as a body man.
First method he used alternating heat from a torch and cold water to tighten stretched metal on a roof panel. I dont have enough experience to attempt that. There is also a shrinking hammer and dolly that could do the same thing, but again best left to someone that knows what they are doing. There is no easy fix. If you paid someone to blast it I would be looking to them to pay for the repair. They don't have any business blasting cars if they don't know what the hell they are doing.

Buddy of mine has a shrinking disc going give that a try. Glady pay some to do it but I don't know/trust anyone local last body guy messed up some stuff and I am just going to do it myself like I should of in the first place.

A old timer mentor of mine called it "oil canning" from back in the days when they had the little oil cans with the disc on the bottom that mived back and forth. Seems that term is mostly applied to metal roofing now.

Torch method goes like this, use your hand to pop it back and forth a few times until you think you know where the center of the stretched metal is. Heat that spot until it is cherry red and place a rag soaked in ice water on the spot. The fast cooling will draw/shrink the metal in. Feel around and see if there is a new or multiple new centers of the oil canning effect and repeated until the panel no longer pops back and forth.

Shrinking hammer method uses a hammer with a sharp spiral pattern on a head that rotates slightly with impact. The sharp spiral grabs the metal and the rotating head twists the spiral inward pulling the metal along with it a tiny bit at a time. You need access to the back of the panel with enough room to hold a dolley for this method.

Seems he showed me another method using the pick end of a hammer and thick leather over a dolley to punch in little divots to take up the warpage, which repair filler and smoothing to cocer up later. Also need access behind the panel. Don't quote me on this method.

Come to think of it, don't quote me on any of this. It was probably 15 years ago he showed me this stuff. But hopefully this will give you some info and ideas on options to further research.

Here is a link to a youtube video where a guy uses a stud gun for a heat source and cold water quenching to shrink an oil can patch in his truck cab corner.

https://www.youtube.com/watch?v=a7wdxmeGHE8

I think if you have never done this before the shrinking disc is the answer.

Shrinking disc can do it. You poke your finger around the outside of the spot until you find the area that triggers the oil can dent to move and then massage that spot with the disc. It will take multiple passes to get rid of it most likely.

Don't press hard, or hold it in one spot for too long.

Quench with a squirt bottle and wipe off with a clean rag.

Dry hand soap to lube the disc as needed.


I think the torch method is not something to even consider with shrinking discs now being available.

I'm not too familiar with the shrinking disc. From the video I checked out though it looked like it was more suited for generating the necessary heat on small bumps. Something like quarter panel stretch from blasting is more likely to be spread across the whole panel, where it looks flat and a large section with no obvious bump to focus the disc's work on.

To each their own though, worth a shot. Let us know how it goes.

Depending on the size of the oil canning, torch with a small tip (00) will work well. heat a area about the size of a quarter no need for bright cherry red when the steel starts to turn red back off, if you watch real close you will see the metal move before it gets red. I`m not much on putting water on steel unless rinsing metal conditioner off. Blowing air a crossed it with a air gun will do the trick you may have to do several areas has it does seem to travel sometimes.

This is coming from a 20 year in the business guy. I tried that whole torch thing to fix the oil canning. Yea. It didn't go so well. It was a extreme spot thou. Dead center of my 69 roadrunner hood. Someone had beat the tar out of it with a ball peen hammer decades ago. It was filled with bondo and painted. Well as you get to know me y'all will realize I can't leave crap alone. Decided to grind the bondo out and tried to dolly most of it out. It started oil canning bad bad. Tried the torch method by heating a spot till the metal started moving and cooling with water. Now the hood is so hard it has become brittle and I'm scare it will crack. Long story short. Try the shrinking disc. If that don't work. Find a professional. And that's coming from a "professional".