Rust removal from inside gas tank

There's a lot of concern nowadays about tank coatings and their susceptibility to the increased level of alcohol in today's fuels. Do you happen to know how well POR15 stands up to this?
 
I was a tad concerned before I used it so I poured some into a soup tin , alowed it to cure(5 days) then added a cupful of unleaded which I left for a week , the POR15 didnt soften at all(maybe not long enough?)..
The only other sealant Ive used is Petseal, it was crap! Softened and peeled!
 
Question
I'm interested in using electrolisis for 2 bad tanks. However I only have a few options for chargers:
1. Battery Tender
2. An RC battery charger (Dynomite Prophet Plus AC/DC 4-7 Nicd & NIMH Peak prediction fast charger
3. Some 2 cell lipo chargers that I could rip apart and use.

Would any of these work?
 
^ I doubt it. I'm pretty sure you'll need something bigger. You can get a manual charger for about $25-$30. You might also try craigslist for a used one if you need something cheaper.
 
I used to make(among other things)stainless boat rails.we electro polished them(they wouldn't really come out polished just a matt finish but they would look the same finish all over we used a dc welder to drive it.
Maybe we (while we are at it )copper plate the iside of the tank:):)
 
That's cool news about the MSR. Sounds like it might be a good all purpose rust remover. Wonder how it works on greasy/rusty parts?

Also, good to know about the line of sight thing.

Before you do anything to derust a tank, I suggest knocking down the worst of it with agitation. I like a couple handfuls of glaziers points
points-put-together-framed-print-200X200.jpg
or roofing nails
6221170.jpg
. Remove the petcocks, roll the tank all around for a half hour or so, dump it all out, rinse with acetone (no residue, dries quick) then either do the electrolysis or MSR whatever.

I too prefer Red Kote over Kreem but whatever you use, you have to get the goop all over the insides. I do this by letting the sealant settle for a minute, pooling in the tank. Then, flip the tank 180 degrees so the goop is on the 'ceiling' of the tank and drips onto the 'floor'. Wait a minute, then rotate the tank 90 degrees and repeat. The idea is that the goop dripping down is likely to not miss a spot like rolling the tank might. Use an lighted inspection mirror to check it out later if you're really anal about it, which you should be.

Let the goop thoroughly cure before filling the tank with gas. This whole process can take a few days altogether.
 
New to the forum and had to post to this one-

DO NOT use electrolysis to derust the inside of a gas tank!!! It would be extremely dangerous to do so. :yikes:

I have used the electrolysis method to derust other parts and it works amazingly well. BUT the process seperates the water into oxygen and hydrogen. When done outdoors and open where the gases can escape, this is not a problem. But when derusting a tank the gases gather into a potentially explosive bubble. Add to that the fact that you have electrical connections (possibly sparking) right there and you have just made a bomb that has the potential of blowing up your garage and allowing your heirs to collect on your life insurance.

I know it's been done, but just because someone else slapped a bear on the ass and still has both arms doesn't make me want to do it myself.

When finished you are also left with a lot of black residue that needs scrubbed off with a Brillo pad or it will return to rust within a short time.

The only safe way to use electrolysis on a gas tank would be to split the tank in half so the gases can't collect, which of course destroys the tank.

Just go for the POR15. Stuff works great and you can pick up a motorcycle tank kit on ebay for about $35.
 
Yep, the POR15 has now been in my Intruder tank for 2 months and has worked a treat..Best sealant/rust converter Ive ever used!
BTW, I love the 'slapped bears ass' analogy ! LOL
 
....
DO NOT use electrolysis to derust the inside of a gas tank!!! It would be extremely dangerous to do so. :yikes:
....

It's fine. Just make sure the cap will vent and set it outside when it's working. No one ever said to do it with the tank on the bike or with the tank even in the garage. :twocents:

Also, welcome to the site! :cheers:
 
I don't know if this method's been mentioned, but I got mine pretty clean using XSJohn's suggestion of a foot of heavy chain, lots of hot water and dish soap, and shake it a long time. Rinse and repeat a few times. Somebody else suggested putting gravel in it, wrapping it in towels and putting it in the dryer. With the heat off! Probably wouldn't blow up, but send the kids out of the house anyway :) I did the final rinse by sticking a garden hose in the filler hole and letting water run out of where the petcock was for about an hour.
 
There is one last method that no one has mentioned=take the empty tank to a radiator shop (but clear wrap the outside of the tank to protect your paint) and they can clean it out for you pretty reasonably and recoat the inside, close to the same price as the kits but no mess or fuss and pretty quick usually,
 
What I suggest using is phosphoric acid. Just fill the tank up and let it sit a couple days. It is very inexpensive and will eat away the rust and leave a phosphorus coating.
 
I started to clean my gas tank 5 days ago using electrolysis method. I clean my steel rod two times a day and I change the water and washing soda solution each day. It seems to work but I still see black residues and little spot of rust in the bottom of the tank, especially where the petcock holes are. I'm using an automatic charger (at 2A) with my motorcycle battery connected in parallel. I tried to select 10A on my charger but its goes on and off fast and I don't want to ruin my battery.

I just want to be sure I'm doing it the right way. I want to use POR15 UTILITY & CYCLE FUEL TANK REPAIR KIT. Here's my question. Can I use the POR 15 kit even if there's some rust in my tank or do I need to use something else to remove it before using POR15?

Here's my "setup"

XS2_18.jpg
 
Is there 'line of sight' from the sacrificial electrode to the rust you are still seeing?

You won't get rid of the black spots using electrolysis.

If you've got most of the junk out, and you use a kit like this http://www.por15.com/FUEL-TANK-REPAIR-KIT/productinfo/FTRK/ you should be ready to go since it also has a cleaner that is supposed to remove rust.

How bad was the tank when you started? How well has the electrolysis worked?
 
Is there 'line of sight' from the sacrificial electrode to the rust you are still seeing?

What do you mean by "line of sight"? (Sorry, I usually speak french)

How bad was the tank when you started? How well has the electrolysis worked?

It was not too bad, light rust on the tunnel and the sides. Most of the rust was in the bottom of the tank. I also found a crack on the top of the tank near the neck and got it welded. I think it works good. The electrolysis removed almost all the rust but I thought it would remove everything. I will continue the process for a day or two. I just wanted to be sure that I did well before ordering the POR15 kit. I won't have the time to do the "POR15 process" now because my girlfriend is going to have a surgery next week. I will fill the tank with gas and stabilizer and do it later.
 
I'll try to explain it a few different ways:
  • You need a direct line between the electrode that you have in the tank, and the rust that needs to get removed.
  • Imagine holding a piece of string from the electrode to the rust. If it wouldn't hit the center hump of the tank, you have 'line of sight'.
  • If the electrode had eyes and could 'see' the rust, it would have 'line of sight'.

Try pointing your electrode toward the side you still have rust on and see if that helps. Be sure to not touch the side of the tank with the electrode though!
 
Thanks Travis, I will try it tomorrow. I keep the anode in the center, always at the same position. I will make a longer one to be as near as possible of the rust. I will let you know the results.
 
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