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fishparts2003
06-24-2014, 7:07 AM
Got a buddy with a dent about the size of a golf ball in the tank. I have heard from more than one person that pulling the tank, draining the gas, filling with water ,and putting in the freezer will cause the expanding ice to push the dent back out. Has anyone done this? Are there any things to know before trying it? Thanks for any input in advance.

BuddhahoodVato
06-24-2014, 7:17 AM
You have heard right,
what I do is take a rubber mallet and whack it around the perimeter of the ding.
then when it's frozen solid I do the same wise,
takes patience hombre.

fishparts2003
06-24-2014, 7:20 AM
Obviously plug the petcock bung with a pipe plug etc, what about the filler. Just use the gas cap? or does the ice expand enough with top left open?

BuddhahoodVato
06-24-2014, 8:49 AM
leave the cap on after you fill the puppy up,
best if the cap is a snug one, helps with the expansion

spidr
06-24-2014, 9:18 AM
Works good as long as all the seams are good. If they where welded and ground down and getting thin, you'd need to worry about it doing more damage than good.

DustyDave
06-24-2014, 9:28 AM
Kind of an iffy procedure sometimes works great, sometimes ya end up wit a vaguely balloon shaped mess. I prefer to boil all the gas out at the local radiator shop then plug the fill and hook a air pressure regulator to the petcock fitting and pressurize to 12 pounds then warm the dent with a torch to dull red sometimes you have to use a little more pressure but be careful ya don't want the afore mentioned balloon.
Dusty

Ato
06-24-2014, 9:32 AM
I'm glad I saw this, I was actually going to try to pull a dent on a buddy's tank so he could try his hand at airbrushing. I was thinking about welding a bolt to the center of the dent and using a slide hammer to try to pull and use a little if necessary to clean it up, but this sounds way better.

DaNgER556
06-24-2014, 9:39 AM
Im gonna have to try this. I have a couple good size dents in my tank

fishparts2003
06-24-2014, 10:02 AM
Thanks for the input guys, I am gonna try and get him to do it at a time I can help/take pics of the before /aftermath etc. Anyone tries it first pics would be appreciated.

fishparts2003
07-07-2014, 2:32 PM
Got my own tank for dent removal experimentation now. Still need to locate a gas cap and block off the assorted holes underneath. If everything goes well I got a tank for my build project. :cool:

LinkBelt
07-07-2014, 3:45 PM
Works good as long as all the seams are good. If they where welded and ground down and getting thin, you'd need to worry about it doing more damage than good.

This is the most honest answer in this thread. Here is a better way, heat the metal surface where the dent is to a glowing red, then hit it with some dry ice. If the dent doesn't pop all the way out repeat the process. Thisnway you don't have to worry about busting the seams.

farmall
07-07-2014, 4:01 PM
If you can weld a hunk of TIG or gas welding filler wire or a nail to the dent then pull it with a visegrip on a slide hammer you can yank dents without piercing the tank. (Screw-type dent pullers are obsolete and do more damage than they fix, though they work well as seal pullers.)

Google "stud welder dent pulling" for theory of operation.

fishparts2003
07-07-2014, 4:13 PM
Am already familiar with the weld something to it and pull/slide hammer method. Thanks Am looking specifically for info related to these others, the freezer trick seems interesting. Is there a way to boil the gas tank or does the radiator shop have special equip. that make it more practical to bring it to them. I would like to be able to cut into used tanks etc, or even use a torch to try the dent removal mentioned above but would like a sure method for gas removal.

Haze
07-07-2014, 4:30 PM
Is there a way to boil the gas tank or does the radiator shop have special equip. that make it more practical to bring it to them. I would like to be able to cut into used tanks etc, or even use a torch to try the dent removal mentioned above but would like a sure method for gas removal.

You need to flush the gas, more specifically the gas-fumes out before getting flames or sparks around it. Taking to a radiator shop and Hot-Tanking (or boiling) the tank will flush the gas along with any dirt or rust out of it... there's other ways to get the gas/fumes out but that is a good and easy way.

Natehate
07-07-2014, 4:54 PM
Got my own tank for dent removal experimentation now. Still need to locate a gas cap and block off the assorted holes underneath. If everything goes well I got a tank for my build project. :cool:


that dent is creased homes these tricks wont work as well

EVILBLACKSABRE
07-07-2014, 5:22 PM
I wish I had a dollar for every time I've heard of the "freezing method" fucking up a tank (the method has been around a very long time). I'm not saying it can't work or never works, but I wouldn't try it.

The thing about water freezing is, it expands and produces pressure in all directions equally, it doesn't just expand where the dent is. Many times I've heard about and/or seen tanks that burst or wound up bulged out/warped.

Personally, I would rather live with a dent than risk destroying a tank by freezing it. But if you are gonna try it, I say good luck. I hope it all goes well.

BuddhahoodVato
07-07-2014, 5:22 PM
Looks to be a good candiadte
got my own tank for dent removal experimentation now. Still need to locate a gas cap and block off the assorted holes underneath. If everything goes well i got a tank for my build project. :cool:

fishparts2003
07-07-2014, 6:44 PM
Anyone have a link to a good educational vid on what happens when you don't flush the gas properly???lol

fishparts2003
07-07-2014, 6:50 PM
I want believe it is more exciting than this ......https://www.youtube.com/watch?v=jKezEwTwl0Y

farmall
07-07-2014, 6:56 PM
You can fill the tank with water with the cap off and weld below the water line since you are just making tack welds and not burning through, assuming electric welding. OA welding and torch work will get the tank hotter so then it's dry tank time.

I like my local radiator shop as they dip 'em cheap and it gets the paint off too. The shop where my wife painted would pull the petcock then run an air compressor into their tanks for a while to dry them out thoroughly. No reason you couldn't leave some air running into the tank to ensure vapor never builds up to flammable concentrations.

You can test for residual fuel like this:

https://www.youtube.com/watch?v=Y5q5WnhjNMg

fishparts2003
07-07-2014, 7:00 PM
Thanks

fishparts2003
07-10-2014, 7:44 AM
Found a radiator shop with a hottank to flush this tank for 20-30 bucks. Will get it back tomorrow.

JamesM
07-10-2014, 5:39 PM
I always just flush with soapy water, and then stick a car's exhaust into the filler for five minutes. Burns off all of the fumes. Have done it with many tanks.
I'm a body man by trade, with dents on a tank I always just slide hammer them. I wouldn't do the freeze trick, but to each his own.

fishparts2003
07-12-2014, 9:27 AM
I always just flush with soapy water, and then stick a car's exhaust into the filler for five minutes. Burns off all of the fumes. Have done it with many tanks.
I'm a body man by trade, with dents on a tank I always just slide hammer them. I wouldn't do the freeze trick, but to each his own.
Wish I had seen this earlier, not convinced the local radiator shop was a great deal. Supposedly "hot tanked" but am not impressed with the results..... through the filler looks good, but through the petcock opening I think there is still some rust. I was under the impression the process would remove the paint too, basically all of which is still there. Am gonna flush it out before I start welding pins to it anyway, smells like solvent of some variety.

fishparts2003
07-12-2014, 5:14 PM
Had to cut out and weld in a patch on the tank today.... I have definitely been had. There is enough remaining rust in the tank I am sure this was not in any hot tank. Also found a red plastic straw like he just sprayed a bunch of WD40 in there and let it sit for a day and washed it out.

Ember
07-12-2014, 10:48 PM
Take it to them and confront them about it.

nuklhd
07-13-2014, 4:49 AM
how much rust is in it? after they hot tank it they have to put something on the inside to keep it from flash rusting. maybe thats what the straw was from. i'm sure not trying to say they did it right or defending them.
the pic of that dented up tank that was shown, if turning the tank into an ice cube takes those out please show the results.

fishparts2003
07-13-2014, 7:51 AM
Don't think I am gonna try the freezer trick with this, started working on the dents yesterday. Got em about halfway clean up at this point. Cut and welded in a patch right in front of the filler, welded pins and used slide hammer for others, tried a youtube science trick for one on the other side. Heated up a dent that was not creased with a Mapp torch and froze the outside of the dent with upside down keyboard duster. Got about half of it out.

JamesM
07-13-2014, 7:30 PM
CLR works great at getting rust out of a tank. Or else if it's really bad this shit rules: http://www.metalrescue.com/home.aspx

fishparts2003
07-14-2014, 7:54 AM
Got my metal work done, have some ripples and such that I can smooth out with some body filler. All went fairly well, pulled some dents, welded a patch in one section, hammered in the dished sides, and learned a fuck load in the process. Now to get the remaining rust out and pressure test. Found a vid on youtube for rust removal, gonna give it a shot. Here is the link, will post results. If it works it is cheap and easy. http://youtu.be/5gH6rSgGr_0 If not I will try some of the more aggressive chemicals offered. Thanks

fishparts2003
07-15-2014, 4:34 PM
I tried the apple cider vinegar rust treatment, unfortunately I have a couple of small places I still need to work on to get this tank sealed perfect. As far as the rust treatment I am impressed. See pics included. Before and after of the filler and bottles of what I drained out. The funnel is after the end of the vinegar was poured out, and the 2 bottles to the right of the vinegar bottle are the clear water flush, after which had been allowed to settle about 15 minutes before the photo. I used the 2 gallons of vinegar from the bottles pictured, and it did not fill the tank all the way so I sloshed it about and let it sit approx. 20 hours. Still had to do more flushing to remove the rest of the rust completely, but looks good and would do this again.

turbonate
07-15-2014, 5:05 PM
Use a uni spitter to put studs all in the dent. Then get about a 1" by"1 by "6" piece of pine and lay it across the dent and lay a set of side cutters down. Grip a stud with the side cutters and pivot it on the wood. You have great leverage and control that way.

lucky13scoot
11-02-2017, 9:30 PM
I know its been a while since anyone commented here but i had a question about body filler. Do you think its a good idea to fill dents that you cant pop out cause they are too close to a ridge? Ive got one and ive been debating bondo vs fibreglass and whether either would be a bad idea cause they might seperate from the tank with freeze thaw. Thanks guys any help is good

Dougtheinternetannoyance123
11-03-2017, 1:09 AM
Wow! reread this old posting and its a horror story of what NOT to do. Interesting all the people advocating the freezer method didnt post up any success pix.. wonder why? They guy who suggests pressurizing with compressed air and THEN welding on it is surely dead by now, or was hoping to get some sucker killed.

As to the question of body filler.. Fiberglass never sticks well to metal, it eventually always seperates. the only way to bond to metal is drill LOTS of holes and SANDWHICH the metal in,, and scuff the hell out of it (like 40 grit). Even then it will usually separate over the years. Its gotta have something to BOND to. Body filler works but only when done right and quality materials, small nicks, scratches and very small dings are the only things to use filler on, and then, scuff the hell out of it and clean well so its got something to grip.

If you cant work the metal with hammer and dolly then use the spot welder and slide hammer setup.. there is kits out there for not much for not much money. Comes with a selection of copper coated nails, slide hammer, and hand held spot welder.

There is no replacement for proper dent removal and body shaping. Freezers and compressed air are a recipe for disaster. (Physics, not just a good idea, its actually a law)

laeljon
11-03-2017, 9:40 PM
Had my dents leaded.....fill with lead. Turn out great.

555
11-18-2017, 1:07 AM
I'm going to try this on an old tank. https://www.youtube.com/watch?v=PNtj-B3I6SA

Abura
12-02-2017, 7:28 AM
I need one. I want to take one it about one week later.

LoudPipesSaveLives
12-02-2017, 9:01 AM
I'm going to try this on an old tank. https://www.youtube.com/watch?v=PNtj-B3I6SA

I like this idea, thanks for sharing.

Skwerly
12-03-2017, 3:04 PM
You need to flush the gas, more specifically the gas-fumes out before getting flames or sparks around it. Taking to a radiator shop and Hot-Tanking (or boiling) the tank will flush the gas along with any dirt or rust out of it... there's other ways to get the gas/fumes out but that is a good and easy way.

This. Fire and gas are a bad idea, so I hear. :D