Cleaning gunk out of old gas tank.

[Leif in Calif]

I have the gas tank out of the car and I see there's a lot of gunk in the bottom. It sat in a field for about 20 years.

Doesn't seem to have any rust but boy is it dirty. There was a radiator shop up the road that was going to boil it out for $80 but I've taken my time getting it out (maybe 3 years) and in the mean time, he retired. I guess since modern radiators aren't repairable, radiator shops have gone the way of TV and radio repair. Any ideas?

Car is a 51' Simca 8 Sport if you care....

[gungeey]

Insert 2 ft of heavy chain and start shaking

[leomara]

Or, have it cooked out.  My 1928 Chrysler tank had black tar like sludge in it and I had it cooked by a place that does tanks and radiators.  When I got it back I sloshed it out with gasoline and the gas came out as whistle clean as it went in.  

[Leif in Calif]

26 minutes ago, leomara said:

Or, have it cooked out.  My 1928 Chrysler tank had black tar like sludge in it and I had it cooked by a place that does tanks and radiators.  When I got it back I sloshed it out with gasoline and the gas came out as whistle clean as it went in.  

That was my plan but I'm having difficulty finding a place that does that anymore. 

[JACK M]

25 minutes ago, Leif in Calif said:

That was my plan but I'm having difficulty finding a place that does that anymore. 

It's like that around here as well. I had a tank boiled and sealed about five years ago and got a good job. But it was the retired owner that had turned over his  radiator/glass shop over to his kids.

The old gut only came in when a radiator or gas tank showed up.

It's an hour drive from me and I hope he's still on the same schedule if I ever need him again.

[JACK M]

My neighbor ties tanks to his cement mixer and follows gungeey's suggestion.

 

[leomara]

If you must tackle this yourself I would think ball bearings may do a better job than chains.

[Gary_Ash]

Pieces of 1/4" -3/4" chain, handfuls of old bolts and nuts for sharper edges, and a bottle of PineSol with a couple quarts of water will help to loosen and dissolve the gunk over the course of a week or so.  Meanwhile, shake, shake, shake your booty!

[pont35cpe]

Maybe a gallon of Berrymans Carb dip.

[31Buick96S]

I’ve used this company on several occasions and have never been disappointed. https://www.gastankrenu.com/

[Axial_Flow]

I have had good luck using a can or two of red devil lye and very hot water.  This goes against the instruction label so proceed with caution.  It will take the tank down to bare metal.

[Mark Shaw]

5 minutes ago, Axial_Flow said:

I have had good luck using a can or two of red devil lye and very hot water.  This goes against the instruction label so proceed with caution.  It will take the tank down to bare metal.

I used Drano Drain Cleaner (lye crystals) hot water and 1/4 minus crushed gravel. 

Only took an hour to clean, but two days to dry in the sun.

[Axial_Flow]

2 minutes ago, Mark Shaw said:

I used Drano Drain Cleaner (lye crystals) hot water and 1/4 minus crushed gravel. 

Only took an hour to clean, but two days to dry in the sun.

Mark, I used a heat gun and stuck it into the filler neck and vented out the fuel level gauge to dry mine out.  At the time I used the POR-15 tank lining kit, its held up for the last 20 years.

[Dandy Dave]

Lacquer Thinner or Acetone will get the gunk out. 

Edited February 2, 2023 by Dandy Dave (see edit history)

[Panza]

I need to clean my tank as well, the problem is that it has two Baffles inside, so I only have access to the center section from the filler neck

[R Walling]

 I have cleaned several tanks using a very strong solution of water and a Zep product. I fill the tank to the top and add several handfuls of sand and gravel. Then by using a pressure washer, I agitate the mixture and end up with a spotless tank.

 

 It takes some time getting the sand out but the results are worth it.

 Ps, remove the tank sender first.

[60FlatTop]

I would cut the top of the tank out and do a thorough cleaning with scrapers and chemicals.

 

Then check for any weakness in the bottom of the tank and weld in sections as needed. Weld the top back on and know everything was right.

[John Bloom]

On 2/8/2023 at 9:06 AM, 60FlatTop said:

I would cut the top of the tank out and do a thorough cleaning with scrapers and chemicals.

 

Then check for any weakness in the bottom of the tank and weld in sections as needed. Weld the top back on and know everything was right.

This......  cut it open in a tactical way, so it can be welded closed and grind the weld before priming and painting if you want a new appearance.  Lots of the liquid, chemical, chain and bolt methods will work getting a ton of stuff out, but in a tank with baffles, I think people who feel like they got their tank clean, would be shocked if they cut it open and saw what was still left in there.

[R Walling]

1 hour ago, John Bloom said:

but in a tank with baffles, I think people who feel like they got their tank clean, would be shocked if they cut it open and saw what was still left in there.

 I cleaned out a tank in a f750 without taking it out, using just a strong detergent. It was perfectly clean up to the level of the detergent at the top of the tank and I was happy, it looked like a new tank... But... there was some scuss on the very top that would fall every once in a while that would plug up the fuel line. I had to remove the tank to do the top. 

Edited February 11, 2023 by R Walling (see edit history)

[John Bloom]

4 minutes ago, R Walling said:

 I cleaned out a tank in a f750 without taking it out, using just a strong detergent. It was perfectly clean up to the level of the detergent at the top of the tank and I was happy, it looked like a new tank... But... there was some scuss on the very top that would fall every once in a while that would plug up the fuel line. I had to remove the tank to do the top. 

That is actually very helpful insight for people that want to use a liquid chemical method and not cut the tank open. If you can make it leak proof, consider having it spend a significant amount of time upside down to avoid that outcome that you had. 

[dodge28]

Can you rig up a steam pot of any sort and direct the steam via a rubber hose into the tank  ? It may take a few hours but it will blow the s***t out without damage. A simple analogy , when my mother asked me to wash the baby bottle I used  handful  of corn grain in the water and shake it violently. Worked like magic. Using sharp edged objects in the tank  will damaged the galvanized finish. Another safe way is to fill the tank with water and cut 2  2inch hole , one on each side of the baffle  with a hole cutting saw and use a pressure washer with hot water. Finally blow dry and solder the holes. Soldering is a technique by itself. 

[Carroll_1]

A tractor, two jack stands, straps, nuts, bolts, etc.  Jump to 2:14.

 

Edited February 11, 2023 by Carroll_1 (see edit history)