How to remove petrol tank rust

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V4 Heaven
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How to remove petrol tank rust

#1 Post by V4 Heaven » Fri Jan 18, 2013 3:06 pm

Hi all,

I will get my tank back from the painters soon and I'll need to sort the rust inside it. Yes, I probably should have done this first so that I wouldn't have to worry about the paintwork.

I've heard POR15 and metal fast mentioned on this forum. Can anyone shed any light on this?

The rust is only light surface rust with a run of slightly heavier rust in front of the fuel baffle plate.

I'm thinking that I buy the POR15 Prep & Ready (Metal Ready) from a website such as this:

http://www.frost.co.uk/automotive-tanks-products.html" onclick="window.open(this.href);return false; (Prep & Ready Metal Ready at £17.00) or do I need their Fuel Tank Repair Kit at £38.00? Do I need the Marine Clean? The tank has no leaks and has been regulary used. I just left it half full one winter and the bare metal developed some surface rust.

Maybe put in some small nuts and give the old girl a good old shaking.

Am I right? Will it affect the paintwork if I spill some onto it? Should I put the Metal Ready in and just leave it for a while?

Thanks!
Gettin' kinda squirrely!

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ixe13
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Re: How to remove petrol tank rust

#2 Post by ixe13 » Fri Jan 18, 2013 3:14 pm

If it's only surface rust , I would use Evaporust as it won't harm your paint like phosphoric acid deruster , shake it once in a while
and leave it there for as long as it need . You can mix it with water 50/50 to keep the cost down .

silverstrom
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Re: How to remove petrol tank rust

#3 Post by silverstrom » Fri Jan 18, 2013 5:55 pm

White vinegar works well and it's cheap. Won't hurt the paint or metal. Just dump a couple of gallons in and leave it for a while. A few shakes later and surface rust should be gone.

Rather than nuts, bolts, or drywall screws, etc, consider a small length of chain to help loosen the rust. It will work just as well and be a lot easy to fish out of the tank. If you do use nuts or similar be sure to count before and after.

If you can remove the surface rust why coat the tank? I would only recommend tank coating as a last resort for a badly rotted or holed tank. All coatings, no matter who makes them, have the potential to break down and cause problems. All it takes is one tiny error in application and you'll be fishing coating bits out of your tank forever. I've seen this with many coatings, including Caswell and Por-15. They need to be applied absolutely perfectly or you'll have problems later. Avoid the coating and avoid potential problems. You'll also avoid potentially damaging your new paint, which is a real possibility with the coating process.

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pstamper
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Re: How to remove petrol tank rust

#4 Post by pstamper » Fri Jan 18, 2013 8:08 pm

I saw this a long time ago. Let me know how it works if you try it. I have an old RD350 tank to do.

http://www.sarge.650wiki.org/tricks&tip ... csetup.htm" onclick="window.open(this.href);return false;"

RZColinPaul
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Re: How to remove petrol tank rust

#5 Post by RZColinPaul » Fri Jan 18, 2013 10:18 pm

I have used Kreem many times with great results and it lasts, unless you store the bike with racing fuel. Kreem is a little bit of a pain to do but worth the effort. Colin from Canada ONT. Ajax.
Motorcycle Gas Tank Rust Removal Technique
READ AND FOLLOW THE INSTRUCTIONS IN THE KIT !!!!!

1. Get a Kreem Fuel Tank Liner. Available at most bike shops, $14. You can also order the complete tank prep kit for $26 if desired, This works best. The kit basically has three parts: part A (acid), part B (MEK), and part C (the liner).
2. Empty the fuel from the tank if it is not already. Remove the petcocks and fuel filters from the tank.
3. Block the openings for the petcocks. I fashioned two stops using a couple layers of heavy corrugated cardboard wrapped in duct tape, cut to fit and held in place with the petcock screws. I sealed them on with cheap silicone sealant (which comes off fairly easily afterward). A wood or metal stop might be more appropriate, but this worked fine for me.
4. If the tank sat with gas in it that evaporated (like mine), clean the tank with a little acetone (or MEK) to remove the worst of the varnish left by the gas.
5. If the tank has large chunks of rust, you may want to add BBs (or chain, etc.) and rotate the tank for a bit to remove the worst of it. Mine didn't need this since it had only small flakes of loose, powdery rust.
6. Mix up a 10% solution of muriatic acid. This is available from most hardware stores as a 20% solution, so just dilute it with an equal amount of water (always add acid to water, not the other way around). I mixed half a gallon of acid with half a gallon of water for my tank. Pour the solution into the tank, taking care not to get any on the paint, unless you plan on repainting. This goes for the acetone or MEK as well.
7. Set the tank on one side for about ten minutes. Then switch to another side for ten minutes... etc. so all the sides get cleaned. I let the whole tank sit with the acid solution for a total of about an hour and a half I think. Look through the gas cap carefully with a flashlight to check the progress periodically. The tank should look brand new inside when done.
8. When all the rust is gone, dump the solution and rinse the tank very thoroughly with water. Immediately clean all inside surfaces with a little acetone or MEK and empty out as much as you can when clean. Any small amount leftover will only slightly thin the liner (which contains MEK anyway). Do not let all the MEK evaporate completely because oxidation will begin right away. Immediately proceed with the next step.
9. Pour in liner according to its directions and follow remainder of directions from liner.
10. The liner may end up a bit lumpy looking, but this is okay, the tank at least sealed and protected. I would recommend doing the whole process outside (for fumes) with a hose handy for diluting any spilled acid. The acid bath may open leaks in the tank if the rust was very severe, so be prepared. If not too large, these can be patched with epoxy filler or by soldering. I was fortunate enough not to have any leaks. I should also mention you may want to check the gasket on your gas cap before you begin any of the process. Mine was so hardened it did not seal properly, but I found a thin rubber gasket at a plumbing supply store for $1.50 which I fit on top of the old gasket for a perfect seal, or turn the existing one around.
Good luck with what you chose Colin :smt003 :grin:
colinpaul@rogers.com
RZ350 race bike
RZ500 stock
RZ500, TSI spec factory tune stage two,ported polished,JL pipes,28m Mikuni carbs,EB brakes, R6r front end, R6r swing arm, YZR fairing, V Force reeds, Olhin shock, Wasp Performance

RZColinPaul
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Re: How to remove petrol tank rust

#6 Post by RZColinPaul » Fri Jan 18, 2013 10:25 pm

pstamper wrote:I saw this a long time ago. Let me know how it works if you try it. I have an old RD350 tank to do.

http://www.sarge.650wiki.org/tricks&tip ... csetup.htm" onclick="window.open(this.href);return false;" onclick="window.open(this.href);return false;" onclick="window.open(this.href);return false;"
I tried this before it worked but it took way to long to do. I then still had to cleen and coat the tank anyway to be safe, I was worried about what I could not see in the tank.
Colin :smile:
colinpaul@rogers.com
RZ350 race bike
RZ500 stock
RZ500, TSI spec factory tune stage two,ported polished,JL pipes,28m Mikuni carbs,EB brakes, R6r front end, R6r swing arm, YZR fairing, V Force reeds, Olhin shock, Wasp Performance

silverstrom
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Re: How to remove petrol tank rust

#7 Post by silverstrom » Sat Jan 19, 2013 12:18 am

RZColinPaul wrote: The acid bath may open leaks in the tank if the rust was very severe, so be prepared. If not too large, these can be patched with epoxy filler or by soldering.
This is why tank coating should always be done before painting. His tank is now painted and I don't see any way of using a coating/liner kit that doesn't end up damaging his new paint. I've seen guys wrap tanks in plastic and then metal foil to save the paint, but you need to be extremely careful. The products used to clean the rust and etch the metal so the liner will adhere will damage paint.

V4 Heaven
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Re: How to remove petrol tank rust

#8 Post by V4 Heaven » Sun Jan 20, 2013 7:13 pm

Think I did it the wrong way round! Should have had a go before painting. Thanks for the advice. Thinking of the vinegar first then see how I get on. If I remember to update this post, I'll let know how I get on.
Gettin' kinda squirrely!

PaulGreen
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Re: How to remove petrol tank rust

#9 Post by PaulGreen » Mon Jan 21, 2013 3:25 pm

Hi,
I did mine with vinegar. It was in a fairly bad way before i started. After soaking for a few days the vinegar was filthy so it clearly removed a lot of stuff. However, it left behind a sludge like residue, maybe some fresh vinegar would have sorted it but the stench from my integral garage was overwhelming and it was permeating into the house - Mrs Green was not too happy.

I went for the electrolysis method. I left it to do its magic for several (5?) days, cleaning the anode or cathode (whichever is the one you stick through the filler cap!) and was pleased with the result.

Good luck.
Paul.

V4 Heaven
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Location: Wiltshire, UK

Re: How to remove petrol tank rust

#10 Post by V4 Heaven » Mon Jan 21, 2013 7:07 pm

Paul - Could you point me in the direction of an information source for this method?

Thanks!
Gettin' kinda squirrely!

silverstrom
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Re: How to remove petrol tank rust

#11 Post by silverstrom » Mon Jan 21, 2013 9:37 pm

Lot's of how-to videos online. Just google "electroylsis rust" and you'll find what you need. Battery charger and washing soda.

Again, best done before painting.

PaulGreen
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Re: How to remove petrol tank rust

#12 Post by PaulGreen » Tue Jan 22, 2013 5:42 pm

Hi,

As Silverstrom said - Google and Youtube. I'm sorry but I cant remember the site I found the info on, but there were hundreds to choose from all using basically the same method. Washing soda (more commonly sold as stain removers in the UK if I remember correctly - but check first!) and a bettery charger.
The solution did froth up quite a lot which made it spill out of the filler cap onto the paint but no damage was done to the paint. I constantly cleaned out any overspill for the first hour or so untli it settled down.

Cheers,
Paul.

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