Kawi2strokes.com Forum

So I am in the process of attempting to de-rust an old fuel tank (it's from a Hodaka) using the electrolysis method. In the past, I have had good success with evapo-rust on tanks that were lightly rusted. This tank was terrible inside with heavy rust and fuel remnants. I have used a solution of Arm & Hammer washing soda and tap water, about 1/3 cup per gallon. Using a piece of steel rebar as an electrode, supported by drilling an angular hole through a block of wood. I was able to get the rebar down to about an inch or two from the tank bottom. With a 12 volt, 6 amp battery charger, I have had the tank cooking for 48 hours. I cleaned the electrode several times and now have just rinsed out the tank a few times to check results.
The tank looks much, much better but still has a ways to go. Can anyone with experience in this process give me an idea of what kind of results I can expect? How long should it take start to finish? Should it eventually get to clean metal? The meter on the charger seems to read between 2-3 amps, mostly around 2. Sometmes the electrode will be warm to the touch, other times cool. At one point about halfway through the process, the tank was foaming up pretty good and was drawing almost 4 amps. Seems like the process worked better early on but now may be slowing down a bit. Am I doing everything right?

You are doing things right. Heavy rust may take a couple of weeks. It is usually best to put a media of some sort in a heavy rust tank, shake it to loosen & remove crusty rust before going to electrolysis.

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Answers are here: http://kawatriple.com/

At some point in time you may want to come up with an inverted V or U shaped electrode for the fwd section of the tank.

J

I had a tank pretty rusty inside. I threw some gravel in it, shook it a bit, then dumped the rust out, did it some more. anyone try CLR? I bought this stuff at lowes not CLR but an equivalent, that would eat rust well, but you'd have to rinse it good and coat it quick.

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74 H2B with reeds and 34mm carbs
75 S3A Ram Air with reeds and 30mm carbs
73 S2A (wife's bike)
71 Yammi RT1B
83 HD Sportster
03 Yammi R1
06 Kaw 750 Vulcan (wife’s bike)
12 Yammi vstar 250 (wife’s bike)

You may need a DC power supply that can push a few more amps. Most battery chargers I tried had circuit protection and
would reset over and over. The first tank I did was so bad once the corrosion was gone it was full of holes and
junk.

This stuff is getting great reviews, and it doesn't appear to be phosphoric acid (which works pretty good).
http://www.metalrescue.com

John

Thanks for the input guys. After about 56 hours of electrolysis, I rinsed the tank out several times to remove the loose stuff that was left over. I then filled it with evapo-rust that I had left from the last one. Shortly after filling with evaporust, I discovered that the tank had begun to leak, Must be a very small pinhole, I can't even see it. Left the evapo in there for about 24 hrs and rinsed a few times again, then rinsed with alcohol and blew it dry. No real flash rusting and it's now ready for sealer. Can't believe only one small pinhole, this one was rusted real bad. Came out clean, but the metal inside is rough and pitty due to the heavy rust.

Next time, I will try to loosen and remove some of the chunky scaly stuff before starting electrolysis. Will also try to come up with an electrode that has more surface area. I saw something about that metal rescue stuff and might have to try that too. Gonna use POR-15 sealer in this one, kit came with the bike when I bought it. I don't plan on running this one too often and it will get drained out after each use, so I'm sure the POR will be fine. All future tanks that need sealer will be getting Caswell, it seems to be the hot stuff that everyone is having good results with. Next up is a 1971 Yamaha DT1 tank, and my KH500 (that one isn't too bad and will probly only need overnight with evapo-rust).

Would muriatic acid work OK for cleaning the insides of rusty tanks? Muriatic generally makes quick work of removing all traces of rust from steel.

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Tried firing every stroke and every other stroke, every stroke is better.

3 H2's, all stock
Seats by Tony O'Connor, they're gorgeous
H2B, converted to H2C
75 Paint & Decals by Brian H
75 Euro Seat by Tony O'Connor
Eldorado Motorcycle Seats, Australia

Whatever one uses the idea is to remove the iron oxide only. Not the good metal which some of the other products do.

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Iron On The Bayou.

Absolutely! I have another hobby which often involves cleaning very rusty corroded 75-100 year old parts and have acquired a selection of acids and bases depending upon the material being cleaned, i.e.; steel, zinc plated steel, cadmium plated steel, aluminum, nickel plated brass or other various non-ferrous surfaces. In my experience nothing is faster than full strength muriatic for heavy rust (seconds) and it will not harm the base metal steel and usually not even the paint. This stuff is powerful and I do it outside with thick rubber gloves, goggles and a water source ready and 50-50 ammonia/ionizing agent (409 or equivalent) for neutralization and final wash. Eliminates all rust fast right down to bright metal but I have not tried it on a fuel tank yet.

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Tried firing every stroke and every other stroke, every stroke is better.

3 H2's, all stock
Seats by Tony O'Connor, they're gorgeous
H2B, converted to H2C
75 Paint & Decals by Brian H
75 Euro Seat by Tony O'Connor
Eldorado Motorcycle Seats, Australia