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bodymen, panel warpage... what to do?

Posted By: Flite_727

bodymen, panel warpage... what to do? - 07/08/08 12:27 AM

well i did it good this time! i warped the heck outta my door while welding in a donor plug to fill the recess around the door handle.(cloning an earlier model) the low spot is "oil canned" it will pop out with pressure from behind, but will pop back when pressure is released. if i understand my research correctly, the steel around the weld has shrunk causing the warping & needs to be streched out to releive the stress. what is the best way to do this???? secondly, how do i prevent this from happining again on the other side, i did the skip around tack weld method, like i always have but this still happened.

Attached picture 4537047-DSCN3925.JPG
Posted By: Flite_727

Re: bodymen, panel warpage... what to do? - 07/08/08 12:28 AM

here is a straight edge held up to the low spot.

Attached picture 4537055-DSCN3922.JPG
Posted By: Kingy

Re: bodymen, panel warpage... what to do? - 07/08/08 01:01 AM

Unfortunately the recess will need to be shrinked, shrank, shrunk to eliminate the oil canning.
Posted By: 318Bruiser

Re: bodymen, panel warpage... what to do? - 07/08/08 02:25 AM

My father used to heat up the recessed spot and then use a sponge with water right above it and have the water rush down to the hot spot. Worked sometimes but he was the body man and I am not. Hope that helps some.
Posted By: moparmojo

Re: bodymen, panel warpage... what to do? - 07/08/08 04:13 AM

I'm not a bodyman, but I think they sell shrinking hammers. If I recall correctly, you have to hammer and dolly the area in a concentric circle to move the metal back toward the center.
Posted By: sthemi

Re: bodymen, panel warpage... what to do? - 07/08/08 04:25 AM

To prevent future problems you can use the heat absorbant playdoh that Eastwood sells or you can tack weld a heavy steel angle iron to the area before you start work and leave it on until it cools.
To fix the already warped panel you can try the heat and chill method mentioned or worst case you can take a die grinder and cut a slit in the warp, tack weld an angle to it to hold it flush and weld up the slit, slowly.. watch the heat when grinding the weld down also..
Posted By: Anonymous

Re: bodymen, panel warpage... what to do? - 07/08/08 04:30 AM

cut a slit in it?!? i would push it back out till it stays, then work it with a body hammer and dolly.
use minimal bondo to clean up the ruff spots.
Posted By: hemigod426

Re: bodymen, panel warpage... what to do? - 07/08/08 05:06 AM

to do it right reheat with bottle torch then dolly it back to substraight with shrinking hammer, then matel file with vixin file to see how close you are
Posted By: G_T

Re: bodymen, panel warpage... what to do? - 07/08/08 05:12 AM

Buy a shrinking disc... Eastwood sells 'em: Shrinking Disc
Posted By: 73cudaproject

Re: bodymen, panel warpage... what to do? - 07/08/08 01:49 PM

Quote:

well i did it good this time! i warped the heck outta my door while welding in a donor plug to fill the recess around the door handle.(cloning an earlier model) the low spot is "oil canned" it will pop out with pressure from behind, but will pop back when pressure is released. if i understand my research correctly, the steel around the weld has shrunk causing the warping & needs to be streched out to releive the stress. what is the best way to do this???? secondly, how do i prevent this from happining again on the other side, i did the skip around tack weld method, like i always have but this still happened.



While welding in an upper rear qtr patch panel I experienced the oil can warp. I was using a copper bar but obviously I welded just a touch to long. I tried a veritical cut to relief the metal but ended up cutting the horizontal weld, pushed it back into alignment, re-welded and I beleive it turned out just fine. I did not have a shrinking hammer. In your case I like the idea of heating and shrinking with a wet rag. Good Luck!
Posted By: Mr T2U

Re: bodymen, panel warpage... what to do? - 07/08/08 02:42 PM

what happened was when you welded it expanded the metal causing a high spot and the panel formed a oil can.
now to fix it properly with a heat shrink.
you need to hit the oil can area UP and then find the highest point in the panel. a lot of times it will not be in the oil can area.
heat this spot up with a torch until it's cherry red, note don't heat up a area any bigger that the size of hammer head, i my myself stick with about 1/2".
now hold a flat dolly behind the heated area. strike the panel around the flat spot with the force of the blows towards the red spot. hit it about 6 times around the circumference of the spot. then strike the heated spot directly forcing the metal you moved towards the heated spot to to shrink.
now cool the heated spot and the oil can should be gone.
you just did a heat shrink.
if not find the next highest spot and repeat the above steps.
the most important thing to remember is heat shrink the high spot of the metal. a lot of times it won't even be in the oil can area it will be next to it.
i myself don't like shrinking hammers and things like that. if used improperly they can make more problems than what you had.
Posted By: 6pkaar

Re: bodymen, panel warpage... what to do? - 07/08/08 03:43 PM

Hope you don't mind if I jump in here. I've got a similar problem with my trunk lid from a different cause. I sandblasted the back side of my 'Cuda trunk lid thinking since there's an inner panel it wouldn't harm the outer sheet metal. The back side looks great, but now there's an "oil can" area on the outside skin that wasn't blasted.....how do I fix that?
Posted By: RobR

Re: bodymen, panel warpage... what to do? - 07/08/08 04:05 PM

Oh Man I don't know how many times I've come across bad B body trunk lids with that problem.
MrT2U has the only way to fix that problem...it does take a while but it is the Quickest and safest way for that type of repair.
That is a bad one you have there !!don't envy you at all...
Posted By: Flite_727

Re: bodymen, panel warpage... what to do? - 07/10/08 01:26 AM

anybody have any experience w/ a shrinking disc??? seems like the most foolproof way to handle this if they work as advertised.
Posted By: convx4

Re: bodymen, panel warpage... what to do? - 07/10/08 01:50 AM

A shrinking disk is a way to apply and generate heat in a controlled area. It takes practice and works in all areas, even if there is support structure in the back. E-bay has then also. I like the larger diameter disk that fit on a larger heavy-duty variable speed buffer/grinder.
Posted By: earlybee

Re: bodymen, panel warpage... what to do? - 07/10/08 02:58 AM

I soak/stir torn newspapers in a 1/2 bucket of water till they fall apart. Then squeeze a handfull of paper paste and make/stick a thick border dam on both sides of where your welding/brazing sheet metal. A real old bodyman showed me this tip for warpage in the 60s when we brazed everything for body panels.
Posted By: 73cudaproject

Re: bodymen, panel warpage... what to do? - 07/13/08 04:10 PM

Quote:

what happened was when you welded it expanded the metal causing a high spot and the panel formed a oil can.
now to fix it properly with a heat shrink.
you need to hit the oil can area UP and then find the highest point in the panel. a lot of times it will not be in the oil can area.
heat this spot up with a torch until it's cherry red, note don't heat up a area any bigger that the size of hammer head, i my myself stick with about 1/2".
now hold a flat dolly behind the heated area. strike the panel around the flat spot with the force of the blows towards the red spot. hit it about 6 times around the circumference of the spot. then strike the heated spot directly forcing the metal you moved towards the heated spot to to shrink.
now cool the heated spot and the oil can should be gone.
you just did a heat shrink.
if not find the next highest spot and repeat the above steps.
the most important thing to remember is heat shrink the high spot of the metal. a lot of times it won't even be in the oil can area it will be next to it.
i myself don't like shrinking hammers and things like that. if used improperly they can make more problems than what you had.

With hindsight I believe MrT2U's method would have been the best solution for my oil can situation. Since I ended up making the horizontal and then re-cutting the vertical seam I am very thankful I had the butt weld type panel clamps...
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