Old gas in 32 tank

3

32phil

Well-known member
I have a 32 tank that is coated with old gas. It came out of a restored car that sat way too long(my bad). The tank is solid and is not rusty but is coated with a black tar like coating of old evaporated gas, kinda looks like coffee grounds. Right now it is sealed with 3 gallons of lacquer thinner and sitting in the sun. Any thoughts on how to clean this out? I was thinking carb cleaner. I know I'll have to repaint it but I don't want to cut it open.
 
I had very good results with the marine cleaner POR15 sells. It is part of thier tank kit, but you can buy it seperately. They
 
32phil said:
I have a 32 tank that is coated with old gas. It came out of a restored car that sat way too long(my bad). The tank is solid and is not rusty but is coated with a black tar like coating of old evaporated gas, kinda looks like coffee grounds. Right now it is sealed with 3 gallons of lacquer thinner and sitting in the sun. Any thoughts on how to clean this out? I was thinking carb cleaner. I know I'll have to repaint it but I don't want to cut it open.
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I think you are on the right track. I have never found anything that disolves varnish any better than lacquer thinner.
 
Hope it isn't totally sealed.... a little vent would be a good idea...... The Por15 stuff I changed position of the tank every so often to get it all wet. Depends on where the old gas was though.
 
I'll second the recommendation for POR-15's marine clean.

When you get the crud cleaned out be sure to check to see if the tank needs coating inside.


Tom
 
I plan on letting the thinner work for a few days then try the POR 15, repeat as necessary. I still have the sending unit /fuel pick up in it so it is vented OK. I'm interested in whatever worked for anyone who had this problem before.
Thanks, Phil
 
I was reading up on Marine clean, which is a water based strong alkali which needs to be neturalized after use. Sorta like Lye water.

At 20 dollars a gallon plus shipping, I think I would stick to lacquer thinner which I know works wonders and I can get for abotu 10.00 a gallon at our local american auto parts store.

I did the gas tank of a 48 dodge truck and the stuff came out looking like tea or weak coffee and I never had any problem again with varnish. It only took about a couple hours soaking to do it too.

JUst my 2 cents.
 
just finished taking 4 gallans of that kind out of my fire truck that had set 12 years. followed advice from here started with laquer thinner 5 days, emptied , another gallan laquer thiner a few day, rinced with desial fuel, let set a few days than finls set powerwaser down filler rinsed with desial and put two quarts of alchol to dry water. this was done with tank in truck but now is clean,
 
i went with the other route. my gas tank was hopelessly coated and rusty. i pulled it and took it to a company in my area that boils out and recoats it. they did a great job and even repainted it. cost was about 700 but I wanted to be sure the tank was permanently clean.
 
A few years back, on the old FordBarn, there was a picture of a gas tank that some guy had strapped to one of the drive wheels of a big old tractor. He had jacked up that one wheel and let the tractor idle in low gear slowly turning the tank. I think he had water and some gravel in it to clean it out. I did something similar to an old Eagle gas can that a neighbor was throwing out. I just shook it by hand. Cleaned up fine.
 
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I'm not sure what swimming pool acid is. What do I ask for when I go to the pool store? Is there a product I can ask for? How much will I need for a 13 gal. tank? Thanks, Phil
 
The swimming pool acid is muratic. You can also get it at most decent size hardware stores. Nasty fumes. Read caution label first and use HEAVY gloves.
 
I've put a long length of heavy chain in the tank with a piece of bailing wire out the filler to retrieve the chain, then shook the hell out of it. Knocks most of the crud and rust out before going on to the next steps to clean it out.
 
The varnish really should clean out with the lacquer thinner without having to resort to some sort of acid treatment. Give it a chance first before taking any more drastic steps.
 
I use Drano crystals if you can still find them out there. 1 can of Drano gives 3 or 4 soaking solutions with the right amount of water added. It is a basic lye solution and will take out everything but rust. I use Ospho, diluted as required, to remove any rust in there. I have never cleaned one in the vehicle since the tank usually has to be repositioned many times to get the smaller amount of solution to soak all the areas in the tank.

Muratic acid will remove rust but the iron oxide will reform within an hour if you don't coat it quickly with something to stop it. Ospho is a phosphoric acid that converts the iron oxide to a more inert phosphate oxide that actually stops the iron oxide from forming.
 
So far.... 2 days of thinner then I let it dry out/evaporate completely. I then put in 2 gals of POR 15 marine clean plus 2 gals of water sealed it up and let it sit overnight. This afternoon most of the hard crud left by the thinner turned into slimy black mud that wipes off on your finger. I'm leaving it sit for the next few days turning over to soak a different section at a time. It is looking 100 times better after just the 1st day of marine clean. I'll let you guys know how it is going. Thanks for all your help
 
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