The Key To A Rust Free Tank.

[Alias]

Muratic Acid. 50% Acid 50% water, shake, sit, shake, rinse, repeat, neutralize with baking soda and water.  Spotless tank. Forgive my post as I am drunk...

[cernunos]

Hmmm...shaken, not stirred...maybe you are the next 007. I've had 'em rust so bad I just bead blasted the inside. Like the acid idea tho', just hope I never need to try it. Here's to our baby GS and all in the forum  

C.......

[Blueknyt]

I think we can stop calling the GS a baby, its what, 15 years old?  

(raiseing pinky to lips)  eye'al THInk eye'al caw him, Minee  Mee!

[cernunos]

Mine is definitely a baby...only has a few thousand miles and it has some much bigger brothers and sisters...GS750, 850, 1000 etc. Yeh I know there were some other smaller GS bikes but they are babies too. Ok here's to the bastard G and the wild forum.

C.......

[Alias]

Now that I am sober I can explain better  :lol: I think it works better than the sand trick, its a liquid so its easy to remove. Just be very careful with it. It must be done outside, the acid and water must be mixed in a separate plastic container. It HAS to be free of dirt, dust, soap, cleaners, etc. The Muratic acid will react with everything and release chlorine gas. It has to be drained away from away from drinking water supplies, and the tank must be rinsed with water before you add baking soda.

[The Buddha]

OK That's a bit harsh... I was using that as a base prep for Kreem years ago ... the problem is it will rust... acid etched steel rusts very easy... There is this new yamaha stuff, that claims to apply zinc chemically... wich may be much better... never tried... but acid etched steel will go rusty rather quick.
Cool.
Srinath.

[Rema1000]

I think it works better than the sand trick, its a liquid so its easy to remove. Just be very careful with it. It must be done outside, the acid and water must be mixed in a separate plastic container.

You could add water to the tank, then add acid to the water... the trick would be not getting a drip onto the tank (use a funnel, a rag and be careful).

Muriatic acid (HCl) will etch rust... and also the steel beneath it.  Like Srinath says, it will leave bare metal, which rusts easily.  Phosphoric acid (naval jelly) is usually a better choice, because it etches iron oxide quickly, but etches iron slowly.  So you don't have to worry so much about getting it out of the tank so quickly.  Also, it leaves behind a smooth coating of iron phosphate over the iron, which does not rust easily, and is easily coated (e.g. with gas tank epoxy).  The coating is brittle, but that doesn't really matter inside a fuel tank.

Sandblasting is good, but also leaves bare metal.  In the autobody world, sandblasting is often followed with phosphoric acid etching to give a smooth surface that will stay free of rust long-enough to paint.

[The Buddha]

Does the iron phosphate flake/chip/come off under vibrations and heating and cooling and end up in the gas... Been reluctant to use it in the tank... I did some side covers for the old some or other I had that had metal sie covers.... my old savage I think... and it was great... the thin scratches in the black side cover were literally invisible after I put it, then of course I filled that with touch up paint... and it vanished.
Cool.
Srinath.

[Cal Price]

Phosphorice Acid does it? I just knew there must be a reason why Colas exist.

[The Buddha]

Yup... coke in the tank as treatment for rust... the effervescence and its rather benign environmental impact... makes me want to try that...
Cool.
Srinath.

[Rema1000]

Does the iron phosphate flake/chip/come off under vibrations and heating and cooling and end up in the gas...

I've wondered the same thing.  I'd feel better if the phosphate was covered with fuel-safe epoxy or vinyl (Kreem).  You can also get fuel-grade epoxy at boat yards which is used to line diesel cells in boats.  I'm not sure what the POR-15 coating is.

The POR-15 literature says it likes to be applied to rusty surfaces, but I would worry that it would not fully penetrate into deeply rusted areas, leaving some extra oxygen molecules to migrate further into the metal.  If I didn't have any leaks yet, I'd ideally prefer to etch most of the rust away (Muratic/Oxalic), then use POR-15's "Metal-Ready" prep (which sounds like phosphoric acid with zinc peroxide, to leave a zinc-phosphate coating instead of plain iron phosphate), then use the POR-15 coating.

Yamaha sold a fuel tank treatment, which included phosphoric acid, then a follow-up with sodium metasilicate.  I'm not sure what sodium metasilicate does; it sounds like a chelating agent, grabbing onto molecules to help rinse them away; not sure why you'd want that right after etching.

Probably for the average guy, you either want something (a) really cheap, or (b) easy to use... and cheap.  Muriatic and Oxalic are cheap, but won't give a lasting surface.  Phosphoric is cheap, but may flake, so use a fuel filter just in case.  

But acids can be a pain to use around good painted surfaces, so POR-15 is kind-of a kludge, but probably does a good enough job just by itself, and won't eat the paint off the outside.  Also, POR-15 Silver has a better chance of fixing tanks that already leak.  All the other methods would widen the pinholes through etching, and also some acid will weep out onto the paint.  So for ease of use, and leaky tanks, POR-15 probably wins.  For cheapness, phosphoric probably wins, but somebody needs to try it in a tank first .  Maybe I'll do that some time.  My fuel system is already a Frankenstein project, and I keep an eye on it.

Caveat: I've used acids and rust reformer (tannic acid + polymer) on car parts, but haven't treated my tank.  I've only read about Kreem and POR-15.

[dane_lindsay]

ttt

[jessright]

Use Kreem,  You can do it in a condo or apt. if it is a well ventilated area...   just have plenty of baking soda handy to neutrilize the acid when you pour it down the drain.
If you use the Kreem kit,  i would recommend getting an extra container of the liner or the whait stuff (the Kreem?).   Just so you don't run out.

And of course, let's not forget,  if you leave your tank full of gas,  it will never rust.  Well unless it is designed poorly like a Kawasaki Concours (it has space below the petcock that never drains where any accumulating moisture will never exit under normal operating conditions).

J

[John Bates]

[dgyver]

...where would you go to buy phosphoric or muriatic acid? home depot came up short...

Home Depot has muratic acid in the garden department.

[The Buddha]

Yep Acid is at Lowes ... pool section, or concrete cleaning or some or other ... I just know where ...
Anyway dont worry about the crap pockets and fluid getting trapped in there ...
You would have to get the acid nuetralised and baking soda is for that ... followed by water ... then I get as much out as possbel with the fuel tap fitting etc then I shove a dry towel in the tank and hold the other end ... 1-2 towels and its dry ... using hot water might help ... as well as running hot car exhaust in it after towelling ...
Next step is MEK and that will take water out too ...
Kreem ... many thin coats is better than 1 thick one. Use 1/4 of that Kreem bottle or less ... total, and no more than 1/8th in 1 run. You pour it in, and slosh it a bit and it will mix with MEK and dilute out ... drain it into a larger container ... milk gallon with the top cut off works great ... next run after the first one dries ... use that diluted one ... 2-3 times and it should be good ... if there is any rusty bits in there Kreem will seal it to the wall ... Its been that way on some of my tanks for like 5 years+ ... no problem ... I move those to where I can see it ... But After the first coat they wont move unless you dump a lot of MEK in it ... so it should get progressively thicker withe less and less MEK for each subsequent coat.
Cool.
Srinath.

[Dwn4whadever]

Yup... coke in the tank as treatment for rust... the effervescence and its rather benign environmental impact... makes me want to try that...
Cool.
Srinath.

Yes back from the dead.... But will coke really get rust from out of your tank... lol

[The Buddha]

Yup... coke in the tank as treatment for rust... the effervescence and its rather benign environmental impact... makes me want to try that...
Cool.
Srinath.

Yes back from the dead.... But will coke really get rust from out of your tank... lol

I like pepsi ... but preferably do diet though, you dont want the bike to get fat do ya ...  ...
Cool.
Srinath.

[Mandres]

Haha, use Diet Coke and then drop a couple of Mentos into the tank to really get it clean 

-M