Motorcycles wear out over time. On the road, the engine, clutch, and brakes wear a bit on each straightaway and at corner. The tires and chain wear noticeably faster. The odd rock thrown up from by a truck can put a permanent scar on a fairing, and a slipped screwdriver can mangle a screw’s head. The changes are slow, but they are fast enough that every fast ride can raise the question of whether or not the wear is worth it (it always is; motorcycles are made to be ridden). The home mechanic does have one oft-overlooked tool for fighting this never-ending entropy in his arsenal, however—electrolytic rust-removal.
Electrolytic rust removal is a fantastic process where electricity is used to reverse the rusting process. Best of all, it’s safe and relatively simple. Check out the links for more information on the science behind the process; here are the tricks of performing the rust removal.
Car battery charger
Part to be cleaned
Sacrificial piece of steel (a piece of rebar is perfect)
A plastic tub big enough to fit the part to be cleaned
Washing Soda / sodium carbonate (heat baking soda in solution to 180F to make washing soda)
Optional: Baking soda, phosphoric acid, acetone, ATF
First, the positive lead from an unplugged car battery charger is connected to a sacrificial piece of steel, and the negative lead is connected to the part to be cleaned. The part is then submerged in a solution of 1tbsp sodium carbonate “washing powder” per gallon of water. In order for the process to work, the sacrificial piece of steel cannot contact the part—the electricity must flow from the steel through the solution and to the part to be cleaned. Then turn on the battery charger.
Every hour or so, unplug the charger and scrub off the piece of sacrifical steel (the process is plating it with rust, and once it’s plated the process stops. Scrub off the rust to begin moving more rust from the part to the piece of sacrificial steel.
We did a gas tank, and used the tank itself as the container. When we were finished (after about four hours), we flushed the tank with water and poured in phosporhic acid for an hour or two to etch the rust-free tank. Then we flushed it with baking soda to neutralize the acid, water to wash out the baking soda, and acetone to absorb the water. Then we sloshed a bit of ATF around inside it before putting it back on the bike and riding away.
Four years later, the tank is still silver inside and the fuel filter is free of any rust particles. We’re big fans of electrolytic rust removal as a way to fight back against corrosion, and will be talking about another way to fight corrosion later this month.