Don't toss your old fuel tank until you try this

[Hedgehog]

Today after pulling a gas tank, rather than tossing it for a new tank I thought I'd give it a second chance. The inside looked rusty. My original thought was need a good cleaning. Since gas is an organic product muriatic acid was my first choice. Then pout in some rest converter from Harbor Freight. So I poured in a gallon of pool acid and waited for 45 minutes occasionally agitating the tank. The Acid was poured out, the tank was rinsed with water and a box of baking soda was added to the tank with some more water to neutralize the acid. An inspection reveled almost new looking galvanizing inside the tank. The thing looks perfectly serviceable. So, rather than tossing an old rusty tank in the scrap pile, try an acid bath, you might be surprised with the results.

 

[Belizean]

HH get some good filtration going on, and time will let you know if you're choice was wise.

 

[Hedgehog]

Inline filters are a MUST no matter what.

Some folks always seem to run for the hills when I mention doing this with acid. In my experience this is the fastest and safest way to remove organic scum from a gas tank. Simply pour it in, let it sit for a short period of time (this time 45 minutes) pour it out, rinse neutralize and rinse again. Don't let it sit for a week, just a short period of time.

There is all kinds of acid, some are good at dissolving metal, some are good for dissolving organic compounds, some are for chemicals like lime deposits. Muriatic acid is used in swimming pools to alter the Ph and is easily removed with water. This isn't the first time I've used it on a gas tank, both my Honda Interceptor and Harley Davidson FLH had gas scum/residue removed with muriatic acid. It is also easily neutralized with soda ash or good old baking soda. There are a number of different acids that I would not use for this process, as acids go muriatic acid is fairly mild. The tank is going to sit in the hot Arizona sun all opened up for a few days to dry. If there aren't any big ol' rusty spots or actual holes by then I think it will be okay to use. Also the factory galvanized surface inside is untouched or factory fresh.

Another discovery. This tank is from my Willys Wagon. No wonder the PO couldn't start the beast, the fuel line in the tank was plugged with tank scum. After running a stiff wire driven by a drill motor through the intake ..... No there wasn't a screen on the tube ..... and flushing with Air/WD40/air fluids run freely once again.

This tank doesn't need to work for very long, The Wagon will be getting a new high capacity tank from The Jeepster Man. An extra 5 Gallons in the tank will be nice here in the wide open spaces of Arizona.

One interesting thing about working with an old Willys vehicle, there are a whole bunch of vendors I never knew existed before.

 

[JimsCJ5]

There is another way to remove rust without Muriatic acid. Google "gas tank electrolysis rust removal". Did this for fun on a motorcycle tank I thought I was going to scrap. Came out pristine and I was able to use it.

 

[Hedgehog]

I don't believe I'm communicating well. The acid wasn't for rust removal, it was to remove the brown rust looking fuel residue. Many people think their fuel tanks are all rusty when in fact they are showing dried up fuel residue. I know this from improperly storing a Honda Interceptor with a full fuel tank. All the gas evaporated leaving the fuel system a total mess. Everybody I took it to for cleaning said it was rust, but it wasn't rust at all. The stuff is very difficult to remove without some sort of chemical. The tank was saved with an acid treatment.

It was my intension to remove the old fuel scum then hit the tank with a chemical rust transformer that hits rust only and leaves everything else alone. At this point the rust transformer is no longer needed.

 

[Belizean]

HH what about something to clean out the fuel residue in one of those nice 6 gallon plastic fuel containers? Lent one out sometime ago and when I got it back had that in there dried out. Left new fuel to soak but didn't help

 

[Hedgehog]

Try a little pool acid. It's not the plastic, it's the scum..... More than likely vinegar, lemon juice or even coca cola will get the job done.