Author Topic: What's your favourite method of fuel tank de-rusting?  (Read 10633 times)

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Offline drumstyx

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What's your favourite method of fuel tank de-rusting?
« on: June 18, 2016, 09:37:13 PM »
Contemplating how I'm going to de-rust my very rusty '78 750 tank. I was almost set on naval jelly, which is definitely the cheapest and easiest option, but I saw a review that seemed to say metal rescue did a fantastic job, while naval jelly (in fairness, not diluted with water to spread it) didn't do much.

Problem is, Metal Rescue is $30CAD/gallon, and you can't dilute it. That's what, $150 + tax to fill one of these tanks? Yikes...

So what does the community prefer?

Offline flybox1

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Re: What's your favourite method of fuel tank de-rusting?
« Reply #1 on: June 18, 2016, 10:31:01 PM »
Kleen strip prep n etch.  $15.
5 hours of soaking and turning...

Photo taken during drying after a few water rinses and an acetone gargle.
« Last Edit: June 18, 2016, 10:33:25 PM by flybox1 »
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Offline Terry in Australia

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Re: What's your favourite method of fuel tank de-rusting?
« Reply #2 on: June 18, 2016, 11:17:23 PM »
Yep, phosphoric acid is the best way to clean a tank. It's pretty harmless (is used in Coca Cola, metal polish and lots of commercial cleaners, not to mention fertilizers) and does a great job. I've tried all the other methods, but Phosphoric Acid is the best. Cheers, Terry. ;D
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Offline Djfob

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What's your favourite method of fuel tank de-rusting?
« Reply #3 on: June 19, 2016, 12:15:44 AM »
Since your talking cad dollars I'm assuming you're up north like I am. Reason I went with metal rescue is that I couldn't get my hands on phosphoric acid from any known Canadian retailers.


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Offline BomberMann650

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Re: What's your favourite method of fuel tank de-rusting?
« Reply #4 on: June 19, 2016, 12:50:32 AM »
Metal rescue worked alright for me.

But that gallon cost $10 more than what flybox used. 

Offline dusterdude

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Re: What's your favourite method of fuel tank de-rusting?
« Reply #5 on: June 19, 2016, 02:39:49 AM »
The works toilet bowl cleaner,love it

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Offline calj737

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Re: What's your favourite method of fuel tank de-rusting?
« Reply #6 on: June 19, 2016, 03:21:01 AM »
Household Distilled White Vinegar is perhaps the cheapest option. Fill the tank completely, soak, rinse and flush with Prep 'N Etch for a protective layer. Done. Vinegar runs about $1/gallon.
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Offline ekpent

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Re: What's your favourite method of fuel tank de-rusting?
« Reply #7 on: June 19, 2016, 04:15:30 AM »
 I am in the Works toilet bowl cleaner camp also.

Offline b52bombardier1

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Re: What's your favourite method of fuel tank de-rusting?
« Reply #8 on: June 19, 2016, 05:31:03 AM »
I do like phosphoric acid and I also like the "Calcium, Lime, Rust CLR" bathroom cleanser.   Getting anything mentioned here and above hot . . . boiling even . . . seems to help in getting rust and varnish out of the tank. The heat softens up the stains and rust and seems to generally rev up the chemistry.  I use an old camping stove to get it hot and then agitate the tank with a hundred or more nuts, bolts, washers, screws, railroad spikes and old sledgehammer heads to break up the rust.  Don't forget to turn the tank upside down to clean the top surface - even though you can't see it, it'll be rusty and stained, too.  Just kidding about the spikes and hammer heads but you get the picture.  And boil whatever fluid you use outside because it can stink up the house pretty bad.

  Whatever method you chose here . . . . DON'T BE IN A HURRY.  This could take a week or more of active effort on your part to get it all cleaned out down to bare metal.  A good effort here in getting it all cleaned out will pay dividends in the next steps of discovering any pin holes in the metal and when you finally put in whatever liner you chose to prevent future rust.

  The fuel tank on my current CB500 resurrection took a week to get clean and I really thought it would be pin holed but it wasn't. And then the urethane liner went in from a motorcycle-sized "POR 15" kit (in silver urethane, not black) and it has worked out great.  This was my seventh POR 15 tank repair and I have never been disappointed but preparation is the key for any tank liner you chose.

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« Last Edit: June 19, 2016, 05:34:47 AM by b52bombardier1 »
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Offline Bodi

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Re: What's your favourite method of fuel tank de-rusting?
« Reply #9 on: June 19, 2016, 06:14:06 AM »
Assuming you're in the Dominion, Home Despot has concrete floor etch in a 4L jug - pretty cheap. Meant to clean your garage bike shop floor before epoxy painting. It's exactly phosphoric acid solution and it eats rust like Garfield eats lasagna.

Offline drumstyx

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Re: What's your favourite method of fuel tank de-rusting?
« Reply #10 on: June 19, 2016, 06:36:45 AM »
Not planning on lining this tank. I've never heard a good word about liners from people that have used them long-term. People have great things to say when they've only used it for a year or 2, but I constantly hear or peeling liners in tanks that were lined 5+ years ago

Offline b52bombardier1

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Re: What's your favourite method of fuel tank de-rusting?
« Reply #11 on: June 19, 2016, 07:28:35 AM »
They peel because of poor surface preparation or they leave too much urethane in the tank on the bottom  which delaminates later.

Avoid these problems and I've never had one go bad. I did my first tank back in 2009 and it is still perfect.

Rick

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1971 School Bus Yellow Aermacchi H-D Sprint 350
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Offline Tews19

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Re: What's your favourite method of fuel tank de-rusting?
« Reply #12 on: June 19, 2016, 07:32:47 AM »
Household Distilled White Vinegar is perhaps the cheapest option. Fill the tank completely, soak, rinse and flush with Prep 'N Etch for a protective layer. Done. Vinegar runs about $1/gallon.


This is my method as well. I spray the inside out with my pressure washer. Then fill 1/4 wheel water and baking soda to coat the inside.... pressure washer inside again for several minutes. Fill with gas and done
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Offline Hwmetzger

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Re: What's your favourite method of fuel tank de-rusting?
« Reply #13 on: June 19, 2016, 08:50:51 AM »
White vinegar and an aggregate (such as large bolts or gravel) works incredibly well. I've restored a pair of CB200's, SL350, and a KZ440 in this manner. I just fill up the tank, add aggregate, and shake it up every once in awhile while I'm working on the rest of the bike. Rinse well with water, coat with WD40 and she's good to go.

Offline Johnie

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Re: What's your favourite method of fuel tank de-rusting?
« Reply #14 on: June 19, 2016, 09:47:52 AM »
If you are not going to line it then you don't need the etching stuff. I just did a tank and used Metal Rescue for the first time. I bought a 5 gallon pail from Amazon for $93 and free shipping. The tank came out real nice. I let it sit for about 22 hours. Tank nice and shiny. I strained the chemical out and can reuse it. Once the Metal Rescue was out I put in a new petcock, flushed it with a gallon of gas. Dumped out the gas and filled the tank with my no ethanal fuel. No flash rust doing it this fast. I did not want to mess up the paint which is why I do not like the Works. Just to caustic.
« Last Edit: June 19, 2016, 09:50:41 AM by Johnie »
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Offline Terry in Australia

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Re: What's your favourite method of fuel tank de-rusting?
« Reply #15 on: June 19, 2016, 06:50:03 PM »
For guys living in the country, go to a farm supply store and buy a gallon of "Phos wash" or similar, it is 100% Phosphoric acid used for cleaning dairy equipment, it runs for about $30 (AUD) for a 5 litre jug, and can be diluted up to 10:1, which then weakens it to about the same strength as white vinegar.

White vinegar is great for light rusting if you don't mind waiting for a few days, but  Phosphoric acid will remove the heaviest rust in a couple of hours. Cheers, Terry. ;D   
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Offline Wingnut74

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Re: What's your favourite method of fuel tank de-rusting?
« Reply #16 on: June 19, 2016, 06:57:22 PM »
I had a tank with a thick layer of varnish and rust to boot. Did acetone and screws and lots of shaking and soak time, two weeks probably. Then bit the bullet and filled tank with metal rescue. When you are done with metal rescue if you rinse with water you have to blow dry the tank pronto to avoid flash rust. Mines looks factory new inside - was very pleased. Got enough metal rescue to last ten years now though 
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Offline Lostboy Steve

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Re: What's your favourite method of fuel tank de-rusting?
« Reply #17 on: June 19, 2016, 07:18:48 PM »
Washing soda and a battery charger works really well for me.
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Offline drumstyx

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Re: What's your favourite method of fuel tank de-rusting?
« Reply #18 on: June 19, 2016, 09:25:07 PM »
I had a tank with a thick layer of varnish and rust to boot. Did acetone and screws and lots of shaking and soak time, two weeks probably. Then bit the bullet and filled tank with metal rescue. When you are done with metal rescue if you rinse with water you have to blow dry the tank pronto to avoid flash rust. Mines looks factory new inside - was very pleased. Got enough metal rescue to last ten years now though

If I went with just 1 or 2 gallons of the stuff, maybe I could get away with rotating the tank every 24 hours for a couple days?

Offline calj737

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Re: What's your favourite method of fuel tank de-rusting?
« Reply #19 on: June 20, 2016, 03:19:13 AM »
Acetone will eat the paint. Metal Rescue will not. Not sure with your last post which product you were going to "get a gallon or two" of to swirl in the tank.
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Offline Wingnut74

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Re: What's your favourite method of fuel tank de-rusting?
« Reply #20 on: June 20, 2016, 06:57:38 AM »
Acetone and screws were for the varnish, and agreed - it will eat paint too, though I was not super careful thinking I would repaint any way, just wiped acetone off the paint when I spilled and it looks perfect (at least where I spilled).  I tried using less Metal Rescue and rotating it but I started spilling it out too much before I replaced tank gasket and it seemed like a PITA, but I bet you could make it work.
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Offline Djfob

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Re: What's your favourite method of fuel tank de-rusting?
« Reply #21 on: June 20, 2016, 07:50:50 AM »
I had a tank with a thick layer of varnish and rust to boot. Did acetone and screws and lots of shaking and soak time, two weeks probably. Then bit the bullet and filled tank with metal rescue. When you are done with metal rescue if you rinse with water you have to blow dry the tank pronto to avoid flash rust. Mines looks factory new inside - was very pleased. Got enough metal rescue to last ten years now though

If I went with just 1 or 2 gallons of the stuff, maybe I could get away with rotating the tank every 24 hours for a couple days?

Metal rescue works best filled all the way, swirling around go with something stronger with products mentioned above.


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Offline chewbacca5000

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Re: What's your favourite method of fuel tank de-rusting?
« Reply #22 on: June 20, 2016, 08:29:19 AM »
$9.39 Sherwin Williams wood bleach.  It nuked the rust and it has not come back.

http://www.sherwin-williams.com/homeowners/products/catalog/wood_bleach/


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Offline flybox1

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Re: What's your favourite method of fuel tank de-rusting?
« Reply #23 on: June 20, 2016, 08:36:57 AM »
$9.39 Sherwin Williams wood bleach.  It nuked the rust and it has not come back.

http://www.sherwin-williams.com/homeowners/products/catalog/wood_bleach/


No hoping on left foot or reciting special incantations required.
interesting.   assuming you mixed it per instructions.
how bad was your rust and how long did you let it soak?
any issue with tank paint?
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Offline bochnak

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Re: What's your favourite method of fuel tank de-rusting?
« Reply #24 on: June 20, 2016, 08:40:01 AM »
I've used both vinegar and Evaporust with good results. You do have to be patient though:

https://www.howtomotorcyclerepair.com/restoring-a-rusty-motorcycle-tank/

I highly recommend Caswell epoxy if you do have to coat it.

Sometimes pinhole leaks appear after derusting and you have to coat it.