Electrolysis

[Old Colt]

This is my first time getting into Electrolysis cleaning of parts. The Tank on my old GS550 race bike was left full of 110 Octane race gas some twenty odd years ago. Ten years after that when I moved to Vermont I noticed the tank was empty, no surprise but I would have to say it was pretty ugly inside it.
Well now another ten years have gone buy and I have now taken my first short ride, Rather short since I only went two miles since I just had a brake fluid reservoir as a fuel source. It is now time to make the original fuel tank usable.
I had bought a gallon of Muriatic acid to clean the tank but this one was too dang rusty inside so I decided it was time to try Electrolysis to clean it out.
I got it set up Saturday afternoon and it has been sizzling away overnight. It was an interesting site looking at it this morning, it looks like someone drew a stout on it.



Here is how the electrode is fitted, I made up a polyethylene plate with a compression fitting in it bolted into the petcock location. I have a sheet rubber gasket sandwiched in there too. In this is a ¼" stainless rod inserted up into the tank. The rod is about a foot long reaching up close to the fill neck. I had wanted to use mild steel but could not find any in my shop.


This afternoon I will dump the water and give it a first look and try to determine how long it will need to run to get it pretty again. Once clean and dry it will then get sealed with POR15.

[Billy Ricks]

Phosphoric acid is what you really want to use for an acid wash. It only attacks rust and leaves the solid metal relatively unharmed. Muriatic acid will eat good metal. Looks like your method is working great and beats submerging the entire tank.

[Old Colt]

Phosphoric acid is what you really want to use for an acid wash. It only attacks rust and leaves the solid metal relatively unharmed. Muriatic acid will eat good metal.

Yes, Phosphoric goes after rust at a much greater rate than clean metal. Muriatic does not care and goes after both at an equal rate. Phosphoric also leaves a Phosphate coating to protect the surface.

I have about 5 gallons of Phosphoric acid here that I use for parts cleaning as well as the Alodine bath that aluminum parts go through as I produce parts.

[Nessism]

Looks like a fun project. I read about electrolysis and tried to do a tank but found my battery charger could not produce enough current to do the job.

A few things to be aware of...

- you need to clean the electrode often, it builds up with gunk and the effectiveness of the electrolysis goes down when it does.

- rust removal is line of site to the electrode which means you need to move the electrode around.

Sorry if you know these things already. You obviously know your way around bikes. Just trying to make sure you picked up on these details.

[Old Colt]

This is a bit of learning for me. I will be curious to see what shadow effect there will be up inside the tank. At this time the top surface of the tank has no solution on it, I would like to make a stand pipe on the filler neck so I can try to get the tank full. It might just be best to find another method to vent it and roll it over at some point.

My battery charger is a 6 amp automatic so I hooked up a small battery for the charger to see so it will run. I have not checked what current it is putting out but the voltage was holding at 12.4V. There is a strong sizzling sound from within so it must be doing something.

If I was a good boy I would get a fuse inline in case the anode did get in touch with the tank. I might go out and dump the tank and give the anode a look and get a first rinse of the tank, I expect it must get a nasty sludge in the bottom of the tank during the process.


When I get the tank done I will pull the Kaz Yoshima pipes off and submerge them in a plastic barrel and hook them up and see how they clean up.

[Old Colt]

On Ed's note I decided to go out and check on the process earlier than originally planned.
I drained the tank and checked the anode, interestingly enough it has dulled down but no buildup on it.


The water had a good amount of debris in it and I sloshed the tank with a garden hose flushing through it. I did not strain that water but more rust did flush through. But I am a long way from done. I poured back much of the dirty solution and topped up with fresh water and hooked up the power and will let it sizzle till tomorrow and check it again.

[Nessism]

I'm surprised you don't have anything on that electrode. When I tried it, even at 2A current, there was very fast build up.

Found this info on electrolysis... http://www.rowand.net/Shop/Tools/Electrolysis.htm

[Old Colt]

Thanks Ed,
Good reading, I do not think i had seen that page.
I think I need to change out my electrode. Now where is that ¼" mild steel rod.

[tkent02]

If you get it to where the rust is all gone, there is no need to coat the tank with POR-15 or anything else... Just don't leave it sitting for years.

[Old Colt]

Part of my intention with sealing the tank is to get the lower surfaces covered. I intend to slosh the tank with Phosphoric acid to give a protective film on the upper surfaces.
At the BMW dealer that I subcontract to they have been finding todays fuel eating through tanks. Some of the German aluminum tanks get hurt bad by the water-alcohol sludge that develops.

[GS1100ez]

when i did my s2 tank
i used coathangers, and swapped them out everyday

and i used TSP which can be found at any box store

you have to make sure the charger does not have an automatic shutoff thingg

you have to get an old one that doesnt have this
i tried 3 chargers and the oldest one(not the most powerful one)
is the one that worked

my buddy bought a new charger which has the automatic shutoff to do do his tank, no go with his either

so from my experiance it cant be an autoshutoff or antiovercharge system

but i had GREAT results

[ALB80-850]

Just thinking outloud, the different electrodes may be the reason for the build up amount. The 1st set being stainless and the other is rebar.

NOW, I find a use for phosphoric acid. There was a gallon of it in my basement when I bought the house 12 years ago. I just took it to the hazardous waste collection last fall. Lucky my tank is clean.

Andy