Rust removal from inside gas tank

I have an automatic charger so I just added a lawnmower battery and the charger keeps it charged while the process is going so if you have a battery you don't need a manual charger
 
This worked for me, I have a `72 XS650, the tank was not too bad but there was rust. I went to walmart, got a small bag of fish tank gravel, smallest diameter and very course, I removed the petcocks and duct taped the holes, dumped the whole bag into the tank then taped the filler hole. I wraped the tank in bubble wrap and taped it very well, I took the tank, put it in the dryer, packed pillows all around it so it couldn`t move, then set the dry on tumble/NO HEAT!!!!! I ran it for an hour, changed position, ran it for another hour. I then pulled it out unwraped it all, dumped all the gravel out, blew out the dust/rust, rinsed with gas, then coated the inside with 10W40!!! When the tank is ready to install, a rinse with gas and it will be ready to go!!!! It looked like a new tank inside!!!!!!
 
I work in an aerospace materials laboratory (37 years). Once a tank is truly clean, a phosphate conversion is a wonderful thing. Now what does that mean? Phosphoric acid reacts with the iron creating an iron phosphate coating. This coating is a great protectorate against future rust. So how do we do this? It requires phosphoric acid and methanol. The methanol just dilutes the acid. Methanol is wood alcohol. The acid reacts with the clean iron creating a phosphate coating. CAUTION, only phosphoric acid and methanol will do this trick. Other combinations can produce toxic nerve poisons or explosives. I don't want anyone dying to prevent rust.

All the Best

Tom

My gosh, this is my second posting
 
Tom,

Great insight - questions.
1. what ratio of phosphoric acid to methanol?
2. Body shop supply houses sell phosphoric acid for rust prrevention. Are they premixed with mentanol?
 
Any phosphoric acid you buy is deluded already. Some are very weak, whereas others are a higher concentration. I use Automotive grade acid, but do not remember the amount of acid in the solution. I knew at one time :( Perhaps Tom can tell us the % of acid that works best considering all things. I use this acid a lot. Not for tanks, but for rust removal and etching on sheetmetal in a car. It really works well and is very easy to use, but you do have to do things correctly to get proper adhesion from paint products.
 
I much prefer to use no sealers unless you really have to do it. My '57 Sporty tank, I had to seal it. I use Master Series, after a full phosphoric acid treatment for several days. Many sealers out there are too easily peeled. Better treating the rust and living with what is left.
 
Using electrolosys isn't dangerous because the tank is full to the top so there isn't enough gas built up to cause an explosion.

I'm with teh bare steel crowd because of the problems with the coatings coming loose. A bare steel inside lasts forever if the tank is full for storage. Will a caoting last forever before it starts to peel off? Coatings make sense to me only when there are pin holes or seam leaks.

I've used junk inside the tank and shake it like a maraca since the early 70's when I dfid my first rusty tank. I've used the method on every tank since before I tried either acid or electrolosys.

Throw some motor oil in the tank to coat the surface as soon as the last cleaning is finished to keep the steel from flash rusting.

Tom
 
The electrolytic rust removal is a top drawer method. You can take an awful rusted mess and take it back to just steel. I have used this method on antiques and such mundane things like chain guards. Now when is the last time you saw a chain guard with no rust? The phosphate mixture is 5% acid to 95% methanol. I have experimented with this and more than 5% does not work as well. This is available in most automotive stores and is commonly known as "metal prep". It is used as a pre-painting coat. This is a really good coating that I have used on armored vehicles. Yes, I said armor as in military vehicles. Bolts are highly prone to rusting once you put a socket or wrench on them. A coating prevents corrosion if the paint is chipped off.

All the Best

Tom the Tommer
 
Regarding phosphoric acid, there's a product that can be found in some hardware stores called Rust Cure:

http://www.rust-cure.com/

It's premixed, ready to apply. I buy it in quart-size spray bottles. I've used Rust Cure on bare iron and steel, the insides of tanks, just plain rusty stuff, etc. It makes an excellent primer too. I coated a "fort" I built for my daughter out of angle iron 12 years ago with Rust Cure, then painted it with Rustoleum. The fort has survived 12 years of Houston weather, and has just recently started showing some pinhole rust spots. Really good stuff.

I've also done the electrolysis route. Actually I prefer a two-step process -- electrolysis, followed by Rust Cure.
 
hi guys .i just did a bmw tank with a product called flame its a mild acid used in the trucking industry for cleaning aluminum wheels and tanks just put in straight and slosh around til ur happy very fast results and wont hurt paint . then rinse out with hot soapy water couple of times .then rinse with straight hot water tank looks like new .then dried out with a hair dryer from filler cap and air line through petcok area dries very fast then por 15 tank sealer
 
hi i dont at the moment but i can check tonight when i get home we but at the local auto parts store here in the north but i will check for u tonight ok
 
Thanks. At google, when I do a search on flame and aluminum wheels and trucking or trucks, all I get are hits about customized trucks that have flames painted on their bodywork. :shrug:
 
ok i have the bottle in my hand .the prouduct is called flame and it looks like auto valet detailing products ancaster ontario and i buy it from the local jobber here in huntsville for ur tank i would use straight and if u wana clean aluminum i mix it half n half then after cleaning use hot soapy water with sos pad and presto nice clean aluminum if u have no luck waynes auto in huntsville sells it iam shure he will ship hope this helps if it doesnt i will get the contact from him thanks

http://www.autovalet.ca-cleaners.html/speproduc_cialtyts when u get the page up click specialty cleaners
 
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I am suspicious about a product that cleans aluminum and removes rust from the inside of gas tanks. I will talk to our plating chemist about this. We have used a chelating solution that dissolves rust without acids. It harms little to nothing. It is a wonderful product. I will get more details and report back.

P.S. the autovalet link did not work for me.
 
thats odd that link didnt work i copied and pasted it anyways there is nothing to fear from the product i have been using for ten years now for both aluminum and have had no issues all the detailing shops use it hear its just a mild form of acid if u do get some just try it a sample piece u wont believe ur eyes it just makes rust vanish good luck and let me know how u make out joe
 
tommerr, what would 'metal prep' do on a brass brush scrubbing rusty chrome? Turn the spots black and keep them from spreading?
 
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