Dent in Tank best process

A damage like that needs to be hammered out then rolled in an english wheel to get smooth metal, which means opening it. Too damn much work! I'd just go with pulling it and tin/lead brazing.
 
I have the exact same issue with my tank. After much research and probably too many phone calls the best method I have found, that will pull sort the crease to near perfect with as little filler or brazing as possible is a metal worker who will open the tank up from the bottom via existing welds and reweld when done. This will obviously not be seen as is opening from initial welds and will be underneath the the tank. I hope this helps. Let me know if you have found a better method and your results.

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Yeah that's a hard crease. I got a fancy study welder since I knew I would use it a lot on my other cars/bikes. I would use the washer or stud method to pull it out gently(be sure not to pull too much and disturb the overall shape of the tank), then use lead, body filler, or both depending on what you want. My CB tank had 1 inch diameter holes for some home depot sight glass contraption someone put on. I welded them up and then leaded over the dents/weld. Might keep it raw for a while, the lead blends in pretty well
 

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This thread is pretty old....but maybe I can help someone else out in a similar situation or at least provide some info. Plus I just like talking metal.

I read a lot of "feesable" solutions in this thread, but the best and fastest method, in my opinion, is to cut an access hole in the tunnel just big enough to squeeze your hand in with a dolly. Then use a hammer and slapper in a dolly-on/dolly-off technique to remove the dent and smooth everything to no-filler finish if desired. If any shrinking is needed you can do a couple of small heat shrinks and then re-planish with slapper and dolly to smooth everything out. Then weld up the access hole and you're all set. Cheap tools will work just fine, and you can have your local welder close up the access hole for cheap, just cut neatly.

The next best option would be a stud welder and slide hammer, but those are expensive, or time consuming to make. You would also need to use more filler with this method, but that's not terrible as long as you keep it 1/16" or less.

A rod through the filler neck would be tough to get a crease like that out. Especially because the tank tunnel doesn't leave much room to fish the rod in and work.

Do not try to shrink using a rosebud tip as I read somewhere in this thread. It puts out way too much heat to be isolated and precise. A welding tip works best.

Cutting the tank up and using an English wheel would not be a sensible ouption, as the posting member said. A hammer or slapper on dolly is the same as an english wheel. The same goes for a planishing hammer.

Also heating and hot-working metal is a poor practice. You will distort the entire panel. There will be a wide spread shrinking effect as the metal cools, and because the metal will be so soft you will get thinning and stretching wherever you try to work.

I've been doing metalwork for a while now, and these are just my opinions. Anyone interested can check out my more recent build threads for examples.
 
ncologerojr said:
A rod through the filler neck would be tough to get a crease like that out. Especially because the tank tunnel doesn't leave much room to fish the rod in and work.

Do not try to shrink using a rosebud tip as I read somewhere in this thread. It puts out way too much heat to be isolated and precise. A welding tip works best.

Also heating and hot-working metal is a poor practice. You will distort the entire panel. There will be a wide spread shrinking effect as the metal cools, and because the metal will be so soft you will get thinning and stretching wherever you try to work.

I've been doing metalwork for a while now, and these are just my opinions. Anyone interested can check out my more recent build threads for examples.

Here’s an example of a “rod through the filler neck” where I needed to keep the paint in tact....

e1e27f2b0842aca3de10baaecb61604a.jpg


The side of that tank was creased top to bottom worse than the OP’s. It’s not a straight rod, and it has a spoon like tip. You run it up and down the crease in a similar action as using an English wheel. You can also work a dolly on the outside.

Like I mentioned before, which you may have missed, the point of using heat is for an overstretched panel that you want to shrink back. I’m not sure if these pics will make sense, but this is from the front end of a Plymouth Roadrunner that was pinned between two trees, so both sides had a nasty crease that sunk in several inches of depth. The creases ran from where the bumper meets the fender to about 6 inches or so above the wheel opening...

461a818d17d78a690f3d43eb716fe476.jpg


6c7c11a51f3b7f32cb44e891ac674d4a.jpg


I used a rosebud to heat the panel in the second pic because after hammer and dolly, it bulged out too far. A rosebud allows you to spread the heat and not get it too focused. How hot it gets has a lot to do with your gas mix adjustments.



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irk miller said:
Here’s an example of a “rod through the filler neck” where I needed to keep the paint in tact....

e1e27f2b0842aca3de10baaecb61604a.jpg


The side of that tank was creased top to bottom worse than the OP’s. It’s not a straight rod, and it has a spoon like tip. You run it up and down the crease in a similar action as using an English wheel. You can also work a dolly on the outside.

Like I mentioned before, which you may have missed, the point of using heat is for an overstretched panel that you want to shrink back. I’m not sure if these pics will make sense, but this is from the front end of a Plymouth Roadrunner that was pinned between two trees, so both sides had a nasty crease that sunk in several inches of depth. The creases ran from where the bumper meets the fender to about 6 inches or so above the wheel opening...

461a818d17d78a690f3d43eb716fe476.jpg


6c7c11a51f3b7f32cb44e891ac674d4a.jpg


I used a rosebud to heat the panel in the second pic because after hammer and dolly, it bulged out too far. A rosebud allows you to spread the heat and not get it too focused. How hot it gets has a lot to do with your gas mix adjustments.



Sent from my iPhone using DO THE TON

Nice work. As I said, just my opinion. I didn’t say that it was impossible to use the rod technique, just difficult. Especially for someone who hasn’t done it before. I’ve seen this pointless dent repair guys do some pretty good work. Those fancy tools they have with the roller ball on the end are pretty cool too. But, if paint isn’t an issue like like the op’s case I still vote cutting an access hole in the tunnel.

As far as using a rosebud to shrink body work, I’ve always been taught that it’s too imprecise. The people I’ve learned from always preach small precise shrink spots with a welding tip. But, to each is own. If you can make it work, rock on.
 
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