How to clean rusted gas tank?

Hey Vlad ..... buddy of mine used a product called POR-15 .... he said it solved the rust problem? .... maybe you can find a website for it??
Mike .....

Dump about 5 pounds of birdshot in to it, seal it up, and shake the bejesus out of it.

BB's work good and don't leave any residue, there have been a lot of bad reports about Por-15, if everything isn't just right the stuff will peel off and plug things up and there's no way to get it out, if you can possibly help it don't use a sealer, if you have to weld it put dry ice in the tank with a little water the resulting CO2 will suppress any explosion that will occur if you don't.

I did use bb's in the past. Just trying to find out is it any another way?...

I like it: "Happiness is A full tank and an empty bladder. "

VLAD - 10/28/2010 10:46 AM I like it: "Happiness is A full tank and an empty bladder. "

The older I get, the more important that is. 😉

I had good results from POR-15.
You must follow the instructions to the letter or it will fail.
If it does fail, toluene turns it back to a liquid for removal. Needless to say, it will eat the paint on your tank.

toluene turns it back to a liquid for removal
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That's what they say and your SO right about following inst's but once it's cured that's it, it hardens to something like a ceramic and the problems occur if rust gets or is under it, it's impossible to get it all out.

BB's mwork fine or so do small nuts and bolts with a dilute solution of phosphoric acid. I gt it at a chemicla supply warehouse and dilute it to about 20%. You have to seal the tank, of course. After the rust is out, acetone or Methyl Ethyl Ketone will absorb any water left inside and dry it out.

Once the tank is clean, I don't coat the inside. I leave it with a patina from the acid and keep the tanks full when parked. I've not had one rust again yet.

I've heard that Pot-15 is OK for coating. I've not tried it. I did try Kreem and couldn't get it to work.

My way was to fill the tank with gravel and shake until the arms become long. Easier is to strap it on top of a concrete mixer and swivel while the mixer does the hard job.
Afterwards I cleaned it out with water and dried in the sun (tropical sun => but a kitchen oven at lowest temperature would do t too) And I poured in some 2 component epoxy recine for fibre glass work and waited a week in stead for a day to dry.
This worked very well for me on my 1960 Willies (1994) and my Jawa Rig (2004) now for 16 and did not smear like the nitro paint I used before in 1982.
Sven

I do this on tanks often..... First you need to clean the tank of any sort of paint or sealer...... a good brand of paint stripper will work....pour it in and slosh it around....let it sit, then flush it out with water.......
Next seal the outlet...and put in Muritac Acid....(swimming pool acid).... that will remove all the rust...and make the iinside of the tank look like new.....
THEN once the tank is dry then you can use POR 15 or a product by Sherwin Williams called Aircraft Sloshing Compound... pour in the full quart....slosh it around....and pour the remainder of the liquid back into the can....seal the can...let it dry in the tank....then do the process over again.... a quart will let you put about 4 layers inside opf the tank....

It is important that you remove all the rust from the tank before you put a liner in... or you will still have rust growing in the tank....

The Red liner that was installed in old tanks is called Glyptol....(electric motor rewind paint).... I don't replace it because today there are much better products today.

Joel

Muritic Acid will ruin paint....and smoke n smell...but will not remove metal... it desolves the rust...and makes metal look new..... but then the metal needs to be covered or it will start rusting immediately. Make sure to wear gloves...and don't breathe the fumes....

When I rebuild car motors... I use muritic acid to clean the water jackets ......it removes rust and all the buildup in the water jackets...so they look like a new ...

It will also make the cement on your shop floor look white and like new.... good cleaner if your trying to sell your house and you want your garage floor to look new. (mine has lots of stains)

Joel
Retired Community College Automotive Teacher

Muriatic acid is a form of hydrochloric acid. Phosphoric acid is much more gentle than muriatic acid. I buy it in 70% solution from a chemical warehouse. I dilute it to about 30% solution. It will clear the rust out of a fuel tank in a few hours. Once dried, it leaves a phosphaticized surface that has a dark silver appearance. If the tank is kept full when parked, it will not rust again. Technicallty, it's called a rust converter. It does an excellent job.

I've done dozens of fuel tanks in this manner with great results.

I'm curious, why not keep it at 70% and cut the time down.