Topic: Gas tank rust removal without harming new paint

[mrbreeze]

I have a tank that I just bought here through another member that I would like to derust. The rust isn't real bad  but it looks like there may be some crap floating around in there. Also looks like some overspray from the paint job. I would like to hear any suggestions as to protect the paint while getting the tank clean on the inside. I also have my old original tank that is rusted real bad and the paint is faded but not real bad. If I were to use the electrolisis method to remove the rust....it wouldn't bother me too much if that paint was messed up but I don't want to harm the new tank's paint.

[Randy]

it sound weird , but used Pam...yup, the crap you spray on your frying pan.... Its just veggie oil its smells , but the a good cleaning afterwards does the trick.. I also used Smart and Final toilet cleaner and hot water and a cheap 99 cents duster.. and it worked great.. I took 2 hours to the tank...

[mrbreeze]

Really? Neither of these products will hurt the paint?

[CoachDoc]

Rusteco worked for me. It's pricey but easy to use and won't damage paint- and it works.

[mrbreeze]

I think I've read about that stuff.......bazillion $$$ per gallon ...won't hurt paint.....can be reused. I heard the toilet bowl cleaners are good but you can't get it on the paint. I wonder how the Molasses is ? Even coca cola....I heard they take longer but what about the paint? Whatever I use ...I'm gonna be real careful and cover the tank somehow but knowing my clumbsy a$$....I'd still get some on there!!!!

[Tews19]

Hang a magnet from a string and watch the rust attract to it... Thats what I have read and should do... I think i read a post where a member has done this and continues to ride with the magnet in the tank to clean.. May take an extended amount of time though.

[nancy]

Search for threads on the topic of using electo-whatever...for rust removal...using battery charger as power source, electrodes in your tank, fill with salty water, power on and leave. Most rust gone. Done this myself on my newly painted tank. Worked.
Getting rid of spray crap and loose rust debris is a different mission. Rinse and empty - many times with water to try and sluce out the crap,...followed by a real good dry down = heat gun inside, towels on a stick,..whatever..and sluce around some ATF in there to coat the inside to prevent flash rust.
I made up a poker out of a foot long (or so) length of 1" water supply pipe - which is hard and non-bendable, but can be heated and worked to form a lovely banana bend to fit into the hard to reach places in the tank. I tied a blob of towel to the end real tight and soaked that in ATF - worked it in everywhere - that helped to remove debris. Wipe it off, redip in ATF and do it all over many times...
Well - that was my story...worked for me. A year and a bit later - inside tank to great.
Regards
Mark

[mrbreeze]

I may just try that if it doesn't hurt paint. I know there are a few posts on it. I have a 10 amp slow charger for cars that should do the trick. I was thinking of using Heet to dry the tank out after rinsing. That or rubbing alcohol and both are cheap. Thanks for the info guys. I think I'll try on my original no dent rusted to hell tank first and see how it does.

[Tews19]

Search for threads on the topic of using electo-whatever...for rust removal...using battery charger as power source, electrodes in your tank, fill with salty water, power on and leave. Most rust gone. Done this myself on my newly painted tank. Worked.
Getting rid of spray crap and loose rust debris is a different mission. Rinse and empty - many times with water to try and sluce out the crap,...followed by a real good dry down = heat gun inside, towels on a stick,..whatever..and sluce around some ATF in there to coat the inside to prevent flash rust.
I made up a poker out of a foot long (or so) length of 1" water supply pipe - which is hard and non-bendable, but can be heated and worked to form a lovely banana bend to fit into the hard to reach places in the tank. I tied a blob of towel to the end real tight and soaked that in ATF - worked it in everywhere - that helped to remove debris. Wipe it off, redip in ATF and do it all over many times...
Well - that was my story...worked for me. A year and a bit later - inside tank to great.
Regards
Mark

Can electrolosis be done with the tank on the bike still? How long does that take? Are you saying this method only works for rust attached to the tank and not loose debris?

[fergie]

Be carefull with electrolosis. The byproduct with this method is hydrogen gas!

[Terry in Australia]

The electrolysis method is good Fred, but painfully slow, and potentially explosive. I gave up and bought a gallon of phosphoric acid (the stuff they put in coca cola) which I diluted with water at 3 parts water to one part acid and I had the rust all cleaned out after 24 hours. This was a tank that was perfect on the outside, but so badly rusted inside that holes had formed in several locations.

The diluted phosphoric acid won't hurt your paint if you quickly remove it with more water, but if you soak it in the diluted phosphoric mix the acid will remove any rust, anywhere, so if there's rust under the paint and the paint has been breached, the acid will unstick the paint from the parent metal. I've got a rusty CB750 battery cage in the mix at the moment, and the paint is just falling off it. Lovely!

The thing I like about phosphoric acid is that you can put your bare hand in it and it won't burn your skin, and you can splash it on your clothes and once again, you won't end up with jeans that look like swiss cheese. Phosphoric acid is used in most chrome polishes, and so is brilliant for cleaning rust off chrome components like fenders, handlebars, header pipes, rims, etc. No good on zinc coated components like spokes, nuts and bolts etc though, it'll strip the zinc off very quickly. Cheers, Terry.

[Greggo]

The molasses trick won't hurt the paint, but it is very slow. 

[sopo400f]

The molasses trick won't hurt the paint, but it is very slow. 

Worked great for me. Only took 5 days.  $7 for a gallon at tractor supply.

[mrbreeze]

Wow....lotsa choices!!! This tank is really pretty and I don't care if it takes awhile to clean it out. I think maybe the molasses might be the way to go because it really isn't that bad. My older tank is bad so I may try the electralysis on that one. On the K1 tank Terry.....it has a big ole dent on the right side but the inside doesn't look bad. I already know you can work magic with the tanks so I'm not sweating that one. I have a coupla more tanks besides those that need some body work done. I'm not a body man or painter so I would rather let the pros handle that end of it. I'll post back here later with my results.

[phil71]

wait, is the paint original?

[mrbreeze]

The paint is original on my old tank that is heavily rusted although its kinda faded. Wouldn't break my heart if I messed up that paint. The new to me tank is freshly painted and looks awesome. The rust isn't really bad at all but I'd be really pissed if I messed up that paint.

[Terry in Australia]

Wow....lotsa choices!!! This tank is really pretty and I don't care if it takes awhile to clean it out. I think maybe the molasses might be the way to go because it really isn't that bad. My older tank is bad so I may try the electralysis on that one. On the K1 tank Terry.....it has a big ole dent on the right side but the inside doesn't look bad. I already know you can work magic with the tanks so I'm not sweating that one. I have a coupla more tanks besides those that need some body work done. I'm not a body man or painter so I would rather let the pros handle that end of it. I'll post back here later with my results.

Thanks Fred, I saw that dent in the pics you sent me, like you say, it's fixable, the real hard ones to repair are the sharp creases at the front of the tank caused by the forks coming around and smacking it hard during a crash. Good to know that it's pretty good inside, it should be worth saving. Cheers, Terry.

[Glenn Stauffer]

There is another water-based product, Evapo-Rust, that works well in my experience.  I've used it on a lot of small parts; the rust is removed, leaving a gray finish to the metal and paint, rubber, etc. is left unharmed.  I found it at my local hardware store for $21/gallon.

[Johnie]

Check out this thread on a no caustic cleaner I used as I also did not want to damage an OEM paint job.
http://forums.sohc4.net/index.php?topic=90270.msg1011695#msg1011695

[Tews19]

Alright so my dirty tank with two fuel filters finally failed. I am heading to the O'Reillys to try Evaporust.. Then off to clean the carbs myself which I paid 475 a month ago to get done.

[Scott S]

 If the rust isn't real bad, just drop in a length of heavy chain and some kerosene and slosh it around, rinse out and go.

[phil71]

+1 on the 'shaking the chain' scenario. do as little chemical work as you can, and just clean your screen a lot in the first few weeks. it'll be okay.

[bollingball]

Tew $475

[Tews19]

Tew $475

sigh, I know

[ZanVooden]

Fill the tank with vinigar. Let it sit for a couple days and rinse out. I did this on a freshly painted tank because the painter had it for 3 months and never moved it around before painting it.

Just filled it full of vinigar and let it sit for 3 days. drained it out. Rinsed it with water, and a final rinse with WD-40, and filled it with gas. Worked for me.

Just make sure that after you fill it with vinigar and leave it that it doesnt get really hot, as the vinigar will expand and spit out the the gas cap vent. I put a rag around the cap and checked before and after work just to be sure.

[cb500bobber]

Muriatic acid works great to I used a hole gallon on mine and then filled the rest of the tank with water and let it set for 2 hours or how ever long till it comes clean. You will need to shake the tank every 15 minutes or until it looks clean. Then rinse it with water and then put oil in the tank and move it around to coat the inside.

[Lostboy Steve]

These threads just keep resurfacing. Do a search. There have been about 30 threads about this since I joined a few months ago.

[gnarlycharlie4u]

These threads just keep resurfacing. Do a search. There have been about 30 threads about this since I joined a few months ago.

this.

that being said:

vinegar works, beet juice works well, molasses is a total pain but works

I'd just etch it with phosporic acid (Prep N' Etch @ home depot) and be careful not to get it on the paint.
It won't mess it up upon contact but who knows what will happen if you leave it on there.

Also be sure to remove your petcock before using any of these.


edit:

Be carefull with electrolosis. The byproduct with this method is hydrogen gas!

yea but unless you're doing it in a small sealed area you're fine.

or you could just put a funnel with a hose on the end upside down over the tank, put the other end of the hose into a water bottle and catch the H gas. then you have minibombs!

[mrbreeze]

These threads just keep resurfacing. Do a search. There have been about 30 threads about this since I joined a few months ago.

If you read the subject....I'm asking about doing it WITHOUT comprimising my new paint. I've been here long enough to know about the search function .....believe me!!!! I'd be here all day scouring over all of the info and then picking out the safest ways of doing it.I don't need no steenkin' search button police!!!!!

[Hinomaru]

I’ve had good luck using the Scotch / 3M Blue painters tape (part number: 2090) on gas tanks. Two overlapping layers does the trick. You still need to exercise caution as the tape cannot offer 100% protection against all cleaning chemical spills. If the tape gets soaked, it’s easy enough to remove and re-apply with some fresh tape. Tip: Waxing the tank with your favorite car wax before applying the tape offers extra protection.
 
More here:
 
http://www.scotchblue.com/wps/portal/3M/en_US/Scotch-BlueBrand/Scotch-Blue/

[mrbreeze]

I have a roll of that (good stuff by the way). You don't think it will take the paint with it when I remove it? It has gas proof clear coat.

[Hinomaru]

If the paint is fully cured, I don't think you will have a problem. The other option is to consider the 3M Orange painters tape, part number 2080EL. It has a lower adhesion factor than the blue tape. I haven't personally tried the orange tape, so I can't vouch for it.

http://www.scotchblue.com/wps/portal/3M/en_US/Scotch-BlueBrand/Scotch-Blue/Products/Directory/?PC_7_RJH9U52308H150IUO3HIL13CO6_nid=VQKRVTF736gs3CJGDZ9S2Qgl8R09XS8RX3bl

[mrbreeze]

I don't have the orange on hand so I'll try the blue maybe down where the seat covers it at first. I would think the paint is cured by now. Its a been coupla months.

[Lostboy Steve]

Yeah I understand the paint thing. About 3 weeks ago a guy had a brand spankin new paint job on his tank and had a whole thread about how to fix the inside after a previous sealer had become #$%*ty.

[lucky]

I think I've read about that stuff.......bazillion $$$ per gallon ...won't hurt paint.....can be reused. I heard the toilet bowl cleaners are good but you can't get it on the paint. I wonder how the Molasses is ? Even coca cola....I heard they take longer but what about the paint? Whatever I use ...I'm gonna be real careful and cover the tank somehow but knowing my clumbsy a$$....I'd still get some on there!!!!

I get so tired of that myth about Coca Cola being acidic.
IF you really think so, try it and find out.
All it will do is get the surface wet.
I don't care how long you leave it on. Or if you put a nail in the bottle of coke.
Does NOTHING.

[mrbreeze]

I think I've read about that stuff.......bazillion $$$ per gallon ...won't hurt paint.....can be reused. I heard the toilet bowl cleaners are good but you can't get it on the paint. I wonder how the Molasses is ? Even coca cola....I heard they take longer but what about the paint? Whatever I use ...I'm gonna be real careful and cover the tank somehow but knowing my clumbsy a$$....I'd still get some on there!!!!

I get so tired of that myth about Coca Cola being acidic.
IF you really think so, try it and find out.
All it will do is get the surface wet.
I don't care how long you leave it on. Or if you put a nail in the bottle of coke.
Does NOTHING.

Guernyville hey? Close enough for me to splash coca -cola at you!!!......Ya gotta come south and hook up for a ride dude!!!!

[Terry in Australia]

I get so tired of that myth about Coca Cola being acidic.
IF you really think so, try it and find out.
All it will do is get the surface wet.
I don't care how long you leave it on. Or if you put a nail in the bottle of coke.
Does NOTHING.

It's no myth mate, Cola (most cola's) contains both Phosphoric Acid (a great rust remover) and Carbonic Acid. When I was an Army recruit back in the 1970's, the gas plugs on our combat rifles would get a  hard layer of carbon on them after a range shoot, and nothing would get it off, nothing that is, except an overnight soaking in a glass of Coke.

Have you not seen the Mythbusters episode where they use coke on a rusty chrome bumper and confirm that it is a great product for cleaning rust off chrome? You're right about not using it to remove the rust in a heavily rusted tank though, the phosphoric acid would be in such a small proportion to the other non-rust removing ingredients, that it won't do much, in fact the other ingredients might even make it rust more. Cheers, Terry.