Removing Rust with Electrolysis

This article is two-fold. First, I’m going to show you how to use electrolysis to remove rust from tools. Secondly, this is the first installment in a series of articles that will take you through the rehabilitation of a hand plane including finding replacement parts, tuning, and sharpening. You can watch as I get the plane back in working order.

Ever get to an auction or flea market and stare lovingly, but in despair, at a hand plane that you’d love to own, but are going to pass on because it’s too rusty? There’s a solution for this problem. Electrolysis. It’s crazy cool, and easy to do. Here’s the overview; submerge the tool in a solution of baking soda and water, connect a battery charger, and let it sit overnight. By the next day the rust will have sloughed off.

The beauty of using electrolysis for rust removal is that you’re not abrading the tool and removing metal. It’s better for the tool, especially if you’re concerned about its value, if you don’t hit it with sandpaper or a wire wheel. This, and the ease of doing it, makes electrolysis the perfect answer for restoring old tools. Electrolysis provides a very easy way to get rust out of a tool’s nooks and crannies.

I picked up the plane in this story cheap. You’ll see it go through the rust removal process here and, in future stories, get to follow along as it’s restored and tuned up.

Electrolysis Rust RemovalElectrolysis Rust RemovalHere’s a Bailey #4 hand plane I picked up for $25. Last patent date on the body is April 1910. It’s sound, but has a lot of surface rust on it, and is unusable in its current condition. I’ll remove all the parts from the body and use electrolysis to remove the rust.
Electrolysis Rust RemovalWhat You Need:

Gather your electrolysis supplies together -
An electrolysis vat that is non-conductive. A plastic five-gallon bucket works well for most tools.
An anode (I’m using a coffee can)
Auto battery charger
Baking soda or washing powder
Measuring spoon
Scotch Brite pad and soft bristle brush
Wire leads
Rubber gloves

Electrolysis Rust RemovalPrep. Wash the tool you’ll be treating. Make sure there isn’t any oil or wax on it that will prevent the electrolysis process from working. Give it a good bath with soap and water.
Electrolysis Rust RemovalMake an anode. You need some kind of sacrificial steel for this. It’s best if the anode surrounds the tool so the electrolysis can happen from all sides. The anode will get eaten up by the electrolysis process, and will need to be replaced after being used a few times.
Electrolysis Rust RemovalConnect one of the wire leads to the anode. Make sure you have a good, solid connection and that the lead is long enough to connect to the battery charger outside of the bucket.
Electrolysis Rust RemovalConnect a lead to the tool. You’ve got to have a good connection or the process won’t work well. This can be challenging with a rusty tool. You may have to clean a small section of the tool with sandpaper to make certain you have contact.
Electrolysis Rust RemovalMake up the electrolyte solution. You need enough water to completely submerge the tool. Add one tablespoon of baking soda or washing powder (either one will work) per gallon of water. Mix the solution to dissolve the powder.
Electrolysis Rust RemovalSuspend the tool in the vat and check the set up. Try to arrange the anode so it surrounds the tool, but don’t let the tool and anode touch each other.
Electrolysis Rust RemovalStart Removing Rust. Connect the clips from the battery charger to the leads on the tool and anode. Make sure you get this right. With the charger unplugged connect the positive to the anode and the negative to the tool. If you do this backwards your tool will become the sacrificial anode. Set the charger on a 2-amp charge and plug it in. Don’t let the connections from the charger touch the electrolyte solution.
Electrolysis Rust RemovalWithin minutes of plugging in the charger you should see bubbles rising from the tool. Allow the tool to “cook” for 15-20 hours.
Electrolysis Rust RemovalResults. After some time the top of the vat will be covered with sludge. This is a good thing. The sludge is the rust coming off the tool.
Electrolysis Rust RemovalUnplug and disconnect the charger and remove the tool from the solution. It won’t look like much now. It’ll need some cleaning.
Electrolysis Rust RemovalWearing rubber gloves, use a fine Scotch Brite pad to remove the sludge from the tool. It doesn’t take much elbow grease, just some wiping.
Electrolysis Rust RemovalUse a soft bristle brush to get into the spots you can’t reach with the pad. Wipe the tool clean using a paper towel.
Electrolysis Rust RemovalAfter the tool is clean and dry, coat it with paste wax so it doesn’t start to rust again.
Electrolysis Rust RemovalThe result? A tool that’s clean of rust. If only I could make a vat large enough for my 1959 Farmall tractor to fit into…

The vat of electrolyte solution is pretty benign stuff, but will burn your lawn if you dump it all in one spot. It’s best to dilute the liquid before disposing of it.

Now that the rust is gone from the plane body it’s time to do some shopping. In the next installment we’ll have a look at the replacement parts I purchased for this tool.

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  • TasieSceptic

    I use a 12v car battery for derusting tools and fittings and keep the battery charged with a trickle-charger, this bypasses the problem of modern chargers that don’t operate without a background voltage

  • Robert Galloway

    Everbody needs a variable autotransformer. Once you have one, you’ll find a hundred and one uses for it. A common trade name is Variac but they’re a little overpriced for amateur use. Plug a 30 amp battery charger into one and then dial in the exact current you want.