A modified method of removing rust from motorcycle gas tanks and other parts
Step 1: Modified Method
This instructables is a modification of the Electrolysis for motorcycle tank rust removal by Professor Sparky.
And a similar one by jimbotheconflictor
Both of these authors fill the gas tank with the electrolyte solution of water and washing soda and then fabricate some kind of steel electrode to put in the solution. Professor Sparky uses a big steel bar wrapped with rubber and electrical tape, jimbotheconflictor uses a bent wire and a wooden plug. In both cases they need to keep the steel electrode from contacting the metal tank and shorting the power supply.
The current flow needs to go from the tank through the electrolyte solution, to the steel electrode. If the steel electrode touches the tank, no rust removal happens. Because the filler opening in the tank is small its hard to get a good sized piece of steel inside the tank. jimbotheconflictor bends a steel wire to fit through the filler opening and down into the tank. If the rust builds up on the electrode it could possibly short to the tank and stop the cleaning action.
I though about how to get this to work better and came up with the idea to use a bigger container to hold the water and washing soda solution. I used a big storage container.
Stuff I used:
My rusty motorcycle gas tank
Soda Ash from a pool supply store, or washing Soda. That's Sodium Carbonate, Na2CO3. Baking soda is Sodium bicarbonate or NaHCO3 and does work also.
A piece of steel (not stainless) or iron
a 12V dc power supply (i had a 6A computer supply laying around) with a couple alligator clips on the leads
A big storage container
Step 2: Plastic Bin
With the big plastic bin, I filled it with the water and soda so that it reaches just above half way full for the gas tank. With the gas tank on its side. So I'll be cleaning one side of the tank, then the other.
I used 1 table spoon per liter. Its a lot more water to fill the bin half way, than to fill the gas tank alone, but its worth it to reduce the risk of shorting and get better venting for the hydrogen gas (which is explosive in air).
The positive still attaches to the tank. The negative attaches to the mild steel piece which is hanging in the solution, but its now in the solution on the exterior to the tank. You can keep it far away from the tank to eliminate the risk of shorting and you can see it, to see how the rust is building up.
This may take a bit longer, but its an open to bin so it will vent the hydrogen better. And with the negative electrode far away from the tank you can leave it alone for longer time with out worrying about a short.
Step 3: Other Parts Too
With the plastic bin holding the water and washing soda solution instead of the gas tank with its small opening, you can de-rust other parts too. You just connect the positive lead to the part and put it in the solution away from the negative electrode piece of mild steel.