oil canning

[RedRooster46]

ive got a dent in the roof that you can sorta see in the one cab pic, ive popped it out but it keeps coming back (oil canning), any suggestions from you guys??

 

[Bonehead]

How big? The bigger they are, the harder they are to get out. It involves a wet rag, and a torch. You may be able to pop it out, lightly heat the edges if it is big, then cool it back down with water to take out the oil canning. I fought one for a long time and never really got it right, but it was dead center, on the ridge.

 

[tator]

use a shrinking disk, they work like magic. Go on e-bay and click on "shrinking disk", I think there is a u-tube link on e-bay.

 

[Tripper]

Slapper!

Like Bonehead said... sometimes it depends on how big & where it is. I have a friend that's pretty good @ using a slapper to get them out. I have one on my '41 I'm gonna let him try.

BoB

 

[Dqracer]

This might help also, a shrinking disc will work it right out .

http://allshops.org/cgi-bin/community/communityalbums.cgi?action=openalbum&albumid=9980121727059

 

[dawg]

The reason it "oil cans" is because the metal is loose, or stretched. The shrinking disc method involves stretching the rest of the roof to recontour the "dome", or crown in the panel. The prefered method is to use a small torch tip (welding tip) and shrink small portions at a time around the perimiter of the low spot, where the stretching occurs. Use a container of ice water and a rag to cold quench the heated area before moving to another spot. Remember, as you heat, the metal will move, because it is expanding. You want to see the panel rise as you heat your small ares, if it caves, stop, and move around the dent and try another spot. Look for small ridges around the dent, and heat and shrink these areas. They are called upsets, and hold tension on the area. They may be super small, so look closely and "read" the panel before you go to heating things up. The shrinking method in the last post using a disc, is really meant for very small areas between dolly marks. It is used more for metal finishing than actually shrinking large loose areas. Like after you have hammered out your low spots on a fender. (hopefully you don't use a ballpeen as in the photos) The disc highlights the high spots and, as such, identifies the lows. After each pass with the disc, you would then raise the lows with a pick or hammer, actually recrowning the panel. In the old days, they used a hammer, and then used a fender wheel (a small hand held english wheel) to iron out the highs and lows, after the hammer work. Both methods are valuable skills, and I would encourage you to learn both, but each one has it's more practical applications...

 

[Tripper]

Thanks!

Dawg,
Thanks for that explanation!

BoB