Remove rust the easy way.
Time A full day
ComplexityBeginner
Cost$0 - $20
Introduction
Electrolysis cleans away rust like magic, and you can set up a simple system in your shop with a battery charger and a few household items.
Electrolysis? I know, electro… what?
What is electrolysis?
In very basic terms, electrolysis is a method to remove rust without using chemicals. By creating electrolysis, we are using a positive electric charge (anodes) flowing through a sacrificial piece of steel — I recommend using rebar — to pull and attract the rust while simultaneously rejecting the rust through a negative electric charge (cathodes) flowing through the rusty item being cleaned while submerged in a conduit of electrolytes, which is a salt solution made with washing soap and water.
TL;DR: The negative charge rejects the rust (attached to rusty item) and the positive charge pulls the rust (attached to rebar).
The cool thing about removing rust with electrolysis is that it’s self-regulating, which means once the rust is removed it stops working and doesn’t eat away or damage the metal.
As you consider using electrolysis to remove rust, don’t stop at rusty tools. When I realized I could safely revive cast iron kitchen items such as pots, pans, griddles and decorative items like cast-iron shoe molds, my world of electrolysis opened to new options. Not to mention, the price of a rusty cast iron pot or antique tool pan is much less than a pristine one!
Warning: Once you feel safe doing this process it becomes addictive. I found it incredibly satisfying to make something old and beat up look new again!
Safety precautions
Science aside, the most important thing to understand when using this method to remove rust is that basic electrical safety really does matter in this process, and it all comes down to connecting the right charge to the right place and turning on the charger when everything is safe.
Along with the tools and materials listed here, you’ll also need a full face shield, safety glasses, and latex gloves.
Follow the steps to the end before turning on the battery charger. Make the electrolyte solution and then attach all connections (positive charge to rebar and negative charge to the rusty item being cleaned) before you turn on the battery charger. DO NOT turn on the car battery charger until you have completed all set-up steps. You want to avoid water splashing or touching any of the parts once the charger has been turned on and the electrolysis process is underway.
Tools Required
- Needle-nose pliers
- Wire brush
- Wire cutters
- Wire strippers
Materials Required
- 220-grit sandpaper
- Battery charger
- Copper wire
- Plastic or glass container
- Rebar
- Steel wool
- Washing soda
- wood)
Watch How to Remove Rust with Electrolysis in a Few Simple Steps
Project step-by-step (9)
Step 1
Set up the plastic tub and rebar
Using a plastic tub that’s large enough to fully submerge whatever it is you’re cleaning, drill holes on one side of the tub and thread plastic-coated copper wire through them to secure rebar, ensuring the middle of the rebar sits at the waterline. You don’t want the rebar to move when the electric charge is flowing into the water.
Step 2
Create an electric current connection between two pieces of rebar
Cut plastic-coated copper wire long enough to connect both pieces of rebar and wrap around the top. Strip two inches on each end of the wire and wrap the exposed copper sections tightly around the top of each piece of rebar.
You can use additional sections of rebar if the thing you’re trying to get the rust off is larger than this, just make sure to secure the additional rebar to the sides of the tub and connect a continuous piece of copper wire to each section of rebar.
Step 3
Mix the electrolyte solution
Fill your plastic tub with enough water to fully submerge the item being cleaned, making sure the middle of the rebar sits at the waterline. Mix in two to four tablespoons of washing soap powder for every one gallon of water. Stir thoroughly to dissolve the soap.
Step 4
Suspend rusty item in electrolyte solution Â
Set up a rigging system to hang your rusted piece from the top of the tub into the water solution. Use steel wire wrapped around a piece of wood long enough to rest across the top of the tub without any risk of falling in to the electrolyte solution. Note: Do not use copper or stainless-steel wire for this connection. Â
Next, attach the item being cleaned to the wire rigging and drop it into the solution so it is fully submerged. You can double up the wire wrapped around the item you’re cleaning to allow more current to flow through it. I also found it worked better to have my rusty item fully suspended in the liquid rather than lying at the bottom. That way, the electric current surrounds the entire surface of the item.
Step 5
Attach all connectionsÂ
- Connect the negative charge (black clamp) to the steel wire holding the item being cleaned. Remember, the negative current pushes away the rust, which is why you want that part on the thing you’re cleaning.
- Attach the positive charge (red clamp) to the rebar.
- Tip: I found making this connection by attaching the red battery charger clamp over both the rebar and exposed copper wire gave the best contact.
Safety first: Make sure neither of the battery charger clamps makes physical contact with the electrolyte water solution. Electricity and water DO NOT mix!
Step 6
Plug in the battery charger and turn it on
With all connections made, step away from the plastic tub and ensure you do not have any contact with the wires or the rebar. Then, plug in the battery charger and turn it on. For best results, I set my battery charger at 10 amps. You should immediately see bubbles in the water as the current flows creating electrolysis to remove the rust.
Let the tub sit in a well-ventilated area where it won’t be disturbed or knocked over, and leave it overnight. When the rust is fully removed, the process will stop.
Step 7
Remove the item and clean it
Be sure to turn off the battery charger and unplug it before you do anything further. Then, remove the battery charger clamp connections from the metal rebar and steel wire connected to the item being cleaned.
Using plastic gloves, take the clean item out of the electrolyte solution, and take off the wire. After that, take it to a sink or use a hose outside to rinse it off thoroughly. Move to a sink with running water or under a hose outside and rinse off thoroughly.
At first glance, it may look like the rust has not been removed. That’s because the ruse is flaked, almost floating on top of the metal, and needs to be scraped clean with a wire or stiff plastic brush to clean away any excess flaking or corrosion. You can also use sandpaper and steel wool to clean back the final layer of gunk. Allow it to air dry completely.
Step 8
Seal item with an oil or a wax paste
After it dries, apply an oil or wax paste to enrich the metal and prevent rust from taking over again.
Step 9
FAQ
Can I repeat the electrolysis process more than once on a rusty item?
Yes, because electrolysis is self-regulating, it will only keep working while there is rust. I found that I could recharge the electrolyte solution by adding more powdered washing soap and doing the process again for stuff with heavy rust, but I’ve not had to run the process more than twice to satisfactorily remove all of the rust.
Will any car battery charger work for this electrolysis process?
No. I tried three different car battery chargers before I found one that actually worked. The newer lithium car battery chargers will not work. They’re not designed to stay on for a prolonged period of time. The most basic of battery chargers with a selection of 2, 10 or 50 for AMPS work best for this.
Will electrolysis work on any metal to remove corrosion?
Electrolysis will work to a certain extent on all metals. However, do not try it with chromed, galvanized or any plated metals as it will eat away at the top layer of the finish, resulting in a further damaged look. Always do a trial run on something you won’t care having ruined. You may encounter variables that will alter the result.
