Hot Rods OLD GAS TANK, big dent.

The second smartest way to do a Good repair to that Tank is to remove one end so you can get inside and control what your doing, then replace the end. You can get Zink in a spray can and give the total tank a fresh coating.

 

This is actually the preferred way as it would be done in a professional setting, all concern for cost aside...
Reason revisited, my son tried 2 radiator shops to have his radiator 'rodded out'. Both told him they had done it, first one didn't even remove a tank.
After questioning him (intensely) he admitted that a back flush was all he did.
Son Rich then marked the tanks, tried the second shop. Bang! Caught the guy in the act...the guy referred Rich to a shop that would remove tanks and perform the act.
Why doesn't anybody solder any more??? Hell, I do!

 

Time...Last Radiator shop I went to charged me $20 for fin straitening which didn't amount to much..Claimed it was boiled but I prob could have done better with vinegar..I would try the 2# pressure..

 

The local Rad shop I use would not remove a tank either for that job. They use an ultrasonic system that brakes down the sediment and then flush it out. New days New ways.

 

Sounds like the way they break up kidney stones nowadays!

 

YES....THIS!

 

That tank looks like it is soldered together. As mentioned I would pick one end closest to the dent . Heat up with a MAP gas torch and carefully with a air hose blow away the solder. You can now do the repairs and when done resolder the end back on.
Vic

 

If you remove the end stuff a deflated basket ball behind the dent and air it up. I have used this on body dents that are hard to get to. If you use pressure use water pressure why do you think they call it hydrostatic test? It will spring a leak not blowup. Tip if I repair a pressure tank I fill it with water then hook up my high pressure washer and run it until I reach my test pressure.

 

Air, as @Pist-n-Broke said, would be my choice. Use a bicycle pump to keep the pressure manageable, and check for leaks at the same time.

 

Harbor Freight sells a 115 volt spot welder......just saying....they help out a lot on dents that you can't really get behind - you use it like a dent puller - spot weld on a little stick weld dilly - and pop out - after you break it off and file smooth...under $100 bucks...........

 

The fun bit of these posts, is some really know; some think they know; and some have no idea but post any way.
Sit back and read 'em all. Then try to work out which is what .
Garpo

 

Bad advice is not Fun or Funny by any means. If I haven't done it I sure as Hell won't tell some poor guy that don't know any better to do it. I have yet to see a stud or bolt used to lift a dent that didn't leave a high spot where it was attached. When you can't get behind that spot what are ya gonna do then? Oh Ya, Body Man in a Can that's a good plan. Do like the guy that built the car RMonty is saving and become a Sculptor not a metal man.

 

I agree with Garpo on this. I have friends who are always willing to tell me how to do something , but when I call them out , they always have some excuse. Like to see these types struggle with the most simple task , but they most certainly can tell you how to do it ?
Vic

 

I had a small metal barrel that I used to carry water for my FED for cool down (no cooling system on the rail). I actually had a hose end cap attached to the fill cap, water hose actually pushed the ends of the barrel out (hey, it held more water now!). That would probably push out the dent if you could control the ends somehow.
I am But ch/56sedandelivery.

 

What about paintless dent tools, I have some old ones.

 

If trying this, (being an old gas tank-as per thread title) perhaps have someone video from a distance so we can see how it goes............

 

I used to think this was a joke, but have found it is the only way I could get beads seated on some tires. I don't know if it would work for this, but if you try it, start small. I had about 20 failures before I got the first one set, but I still had my eyebrows when I was done.

 

I've probly seated 100 tires with starter fluid, as recently as a couple weeks ago. It's a pretty extreme explosion, you would definitely have to start small. I've also welded enough motorcycle fuel tanks that I no longer tediously wash them out. Just drain the gas, flush once with water to remove the remaining liquid and then a flame. The result is a quick WHOOSH out the filler hole from the remaining fumes, potentially about right to push out a mild dent, though I've never deformed a tank this way. I'd still be concerned about the results in this situation, unless it was a potential throw away tank.

What I do for motorcycle tank dents is bend a piece of 1/2" plumbing pipe so it will reach the dent through the filler hole, smash the end into a spoon and apply pressure while tapping on the circumference on the outside as mentioned.

 

If using air pressure fill with water and use a hand pump to control it. Do not use starting fluid unless you want to create a bomb.

 

there is a big difference between a tire bead and a fuel? tank.the pressure in tank will blow out through the filler if you are lucky if not lucky it will lessen the gene pool.which may not be a big loss

 

If I was to guess, I would say that by the 2" pipe thread flange and galvanized finish, I would think that the tank is from an old water system possibly an expansion or storage tank.

 

This is hilarious! Put some air in that bitch, use a regulator a few pounds won't blow it up, I'd even gently heat the dent with a rose bud if needed.

 

A possible alternative that I haven't seen mentioned yet is to fill the tank with hydraulic fluid. Then get a hand operated hydraulic pump. Rig a valve to seal the opening. You could S-L-O-W-L-Y start pumping in more hydraulic fluid and see where the pressure was forming. Maybe even use a rubber mallet along the edge of the dent to help relieve the stress and push the dent out.

 

If indeed this tank is a gas tank or if it ever had gas in it my advice is don't go anywhere near it with a torch. Just before I got out of the Army I spent 6 weeks working in the Post machine shop as part of a transition to civilian life. The shop supervisor related a story about a local who tried to cut into a 55 gallon barrel which by all accounts had been sitting empty for 30 years but at some time prior it had held gasoline. The empty barrel exploded as soon as he cut into it killing him. The super's point was that you never use a torch near a container that once had gas in it no matter how long it had been empty. Advice I heed to this day.

 

One way I used to remove dents in headers is seal up both ends, then pressurize the tube with air and heat the area with a torch. Dent comes out nicely.

Ad far as heating, welding gas tanks, I've done a few. Two good washes with Dove dish soap with hot water. Then rinse for 10-15 minutes with a garden hose and your good to go.

 

I removed a dent in a more conventionally shaped fuel tank last summer with careful application of compressed air, using a rag wrapped around a blow gun held in the filler neck.

Make sure to use a blow gun (or operator) that isn't only full blast all the time, and it's quite controllable.

 

What about the fuel that gets into the metal of the tank,
Or,
Just read post 54 above to see what I am getting at.

 

According to some of these posts I should be Dead by now.

 

I am always intrigued by the number of people that weld up gas tanks, and maintain that a water wash or two will make it perfectly safe.
Then there are those that won’t do it under any circumstances.
Generally those in the second group know someone personally who has been in the first group and have seen or heard the consequences of when it didn’t go so well.
I guess it is up to the individual to decide for himself/herself !

 

Maybe next time, maybe not........