Some thoughts on cleaning heavily rusted steel parts using electrolysis

The one problem that anyone who undertakes to restore any kind of old machine or tools is rust. The problem, if there is a lot of corrosion, is how to get the thing disassembled without doing any damage. A penetrant is usually the first option such as WD40, or my preferred choice Brunox, then Plusgas. On the scale of escalation, according to the severity of the problem, is heat, using the gas axe. But what happens if that doesn't work? How do you get things apart without destroying it completely or partially to get the part required?

I have to say that YouTube for me has been an education, in mostly how not to do things. There is the odd pearl amidst swine, but the majority is mostly how not to go about doing things.  The go to tool seems to be the wire wheel in the bench grinder to clean anything rusty, the vlogger's confidently grind away any patina and finish in their quest to 'restore'.  I am not a fan and it is not an approach I advocate or use. That is not to say a bench grinder with a wire wheel does not have a place in the workshop, as it most certainly does, but it should not be the tool of first resort.

One of the methods I use to get heavily rusted parts cleaned or to get apart is to use electrolysis. It is the best method I have found to clean back to bare metal, where you are not trying to preserve the original finish. It is a simple, inexpensive and non destructive method to clean corrosion off steel and cast iron. It doesn't work on aluminium. You will need a tank for holding the electrolyte solution. I use a plastic hot water header tank sold in plumber's merchants for use with a central heating system.  It is big enough for most bicycle parts. It will hold the warmed electrolyte without reacting to it - IMPORTANT. The power supply is an old car battery charger, the non-smart type, which doesn't know a battery is not connected to it. If you only have the smart type, connect it to a battery, but take your power feed from the battery.

The type of electrolyte you use is important for two main reasons. The electrolyte allows the electric current to flow through the solution which facilitates a chemical reaction to take place. A by product of that chemical reaction is the release of gas, which is why electrolysis needs to be carried out in a well ventilated area. The electrolyte consists of a liquid and an additive. Most hot plating processes use an acid as the liquid. You can use acetic acid (vinegar) with table salt. It will work, however, two caveats. Firstly, if the metal is pitted by rust before you start, using an acid electrolyte will make the pitting worse, because, although the method is quick, and will do the job, it is aggressive. Secondly, table salt is Sodium Chloride. If you use salt in the electrolyte, the process releases Chlorine gas. Yes, that's right, the stuff that was used to gas troops in the First World War, so it is damaging to your health. A very good reason not to use it in my opinion, as there are other and in my opinion, better methods to achieve the goal.

The electrolyte I use is washing soda crystals, an alkali  These are much superior chemically to baking soda, which is much less effective.  Washing Soda is an alkali salt which does not appear to corrode the metal aggressively during electrolysis. Using this method also releases gases, which are oxygen and hydrogen. An explosive mixture! So you have to do it in a well ventilated area.


I suspend the part to be cleaned in the electrolyte solution. I use steel wire, NOT copper. I found that the flexible plastic coated wire sold in garden centres is ideal. The plastic has to be stripped off the wire wrapped around the part to make a good electrical contact. A portion of the wire at the other end has to be bare metal for the battery charger to connect to. I use a piece of scrap wood (a non conductor) which is wider than the tank to suspend the part from.

You will also need a piece of sacrificial steel in your tank. This is needed as it will attract all the rust particles.  I would recommend that it has a flat surface and secondly that you use as big a surface area as you safely can. DO NOT allow the sacrificial steel to contact the part you are trying to clean.  I welded up a frame which fits around the sides of my tank, which is removable for cleaning. (You can use one or more sacrificial pieces, wiring them in series if you prefer.) Cleaning the sacrificial electrode is an important point, as heavily corroded parts will need a longer time in the tank.

You connect the black lead to the part to be cleaned and the red lead to the sacrificial electrode. Once you turn the battery charger on, you will see bubbles coming off the part. I usually set the charger to work on trickle charge. If the charger has an Amp meter you will see the needle move up the scale. As the sacrificial electrode becomes contaminated with rust off the part, the amperage will fall. Turn the power off before removing the part from the tank to check progress. If the part still has surface rust, remove the sacrificial electrode and clean off the accumulated crud.  The wire wheel on the bench grinder is good for cleaning the metal after the crud has been scraped off, before you put it back into the tank. The surface of the part will go black as the rust is removed. This is an inert chemical coating replacing the rust, which will clean off.

The electrolyte can be left in the tank for re-use. The plastic hot water header tank has the option of a lid, which is useful for covering it after use. I remove the sacrificial plates before covering up the tank after use. You will have to periodically replace the sacrificial steel electrodes, but you should get a lot of use from them before that happens. Cleaning them after use is also important as the process works better when the sacrificial electrode is clean.

Once you are happy that your part is thoroughly clean of rust, it will need washing in warm soapy water. Brush the part using a brass brush and then clean it with WD40 or Brunox. Electrolysis will take off any plating or paint as well as rust, so electrolysis will get your part back to bare metal.  If you use it to clean any cast iron such as old tools, once you have the part cleaned with WD40/Brunox, wipe the cast iron part over with boiled linseed oil on a bit of kitchen roll. Make sure it is evenly coated and put it near a radiator or other heat source to dry. It will seal the cast iron ready for painting and should ensure the porous cast iron doesn't start to rust under the paint. I was told this by an old man who maintained machinery in the workshop during his apprenticeship nearly 70 years ago. I have found that cast iron I had media blasted and immediately primed, then painted has all rusted from below the paint over time. Boiled linseed oil was a component in both old paints, varnishes and of course Japanning laquered finish.

I have used the boiled linseed method on cast iron and found it to work very well. If cleaning old cast iron, any paint residue will likely be lead based paint. Not something you want to inhale as dust through sanding or using a wire brush in an electric hand tool or bench grinder. Once the boiled linseed oil has dried, it will take paint no problem, I generally give the item two coats of boiled linseed oil allowing each to dry before the next application. The item should not rust once coated and will stay stable if there is any delay in painting it.

Springhill Cycle Collection - Cleaning rust from plated parts

As I get older, I often wonder about whether there is a smarter way of doing things.  I look back on the way I have done things in the past and cringe.  The old saying that 'a man who never made mistakes, never made a thing' is certainly true.  We all make mistakes and the on the workbench is no different. There is nothing that beats learning by experience.

What is the best method for cleaning rust from plated bicycle parts? Anyone who has tried to restore an old steel bicycle will have come across this problem. I have to say from the out set, or get go, (US English), I am not a fan, or advocate, of the wire wheel in the bench grinder as a first resort. I cringe at the 'experts' on Youtube who confidently reach for the bench grinder first.

My approach to dealing with rusty parts has changed over time. Years ago I used a knife blade to scrape across the rust to remove the surface crust before treating the part with aluminium foil and Autosol or something similar. The problem is that the rust was never completely removed and always came back, so the option always seemed to be the most permanent was the expensive one of re-plating. Is there any method of tackling the rust which will not damage the plated finish or painted finish of the part?

Well I have to say, I have found a method that works. The problem of any restoration is balance. Do you destroy the original finish or do you have to refinish the part to preserve it? Is it financially viable to re-plate?

I have found a product that will clean rust from parts. It is bio-degradeable and non toxic. It was developed for NASA and is called Evaporust.  I had a problem trying to get my hands on some, because the UK supplier didn't supply the whole of the UK. My order was cancelled on ebay. So I had to get my initial order from Ireland. Slightly more expensive but delivery was not a problem and Kevin couldn't have been more helpful and friendly. The chemical is not cheap, but it is very effective.

I have used it to clean various parts, in various states of decay, to see how it coped. It works very well on plated parts and japanned parts. I can see how it can be used to restore a complete bicycle preserving the original finish. It does not prevent the part starting to rust again. Evaporust does have a product which will prevent rust again for up to 12 months, but I haven't seen this for sale outside the US. I have just wiped the parts over with WD40 after washing in soapy water, once they came out of the chemical. The cleaned parts are stored in airtight containers.

The one caveat that I would say is, I tried it to clean parts off an old Claud Butler bike which had been stored in damp and less than ideal conditions prior to purchase. There was a heavily corroded lamp bracket on the front fork. I put that in Evapo-rust and it cleaned a lot of the rust off, however there were several areas of pitting in the surface which still had rust. I attacked this with a brass brush and then put the part back into the solution. 24 hours is usually sufficient to clean parts, but the lamp bracket took a week and repeated use of the brass brush to dissolve the rust. I treated it with several coats of Kurust once clean. It should prevent further deterioration. I would not use Evaporust for heavily rusted parts again. It is no criticism of the product, I just find it is expecting too much of it. I would use another method to clean heavily rusted parts which I will detail in another blog post. The photos show some before and after shots and other parts that have been cleaned.

I have no connection to the manufacturers of Evaporust or their agents, other than as a satisfied customer. Any of the product I have used, I have purchased myself.

Cleaning alloy cycle components

I was doing some internet searching in relation to a bike I had to work on for the Springhill Cycle Collection. The bike, an early 1970s model, had been stored in less than ideal conditions and the alloy components were showing signs of surface corrosion - not been cleaned before it was stored. The components were a Spanish copy of Campagnolo and in parody of the great Roman cycling god, the copies were named after the ruler of the Greek Olympian gods, Zeus. Frank Berto in his tome 'The Dancing Chain' doesn't rate Zeus components. Zeus components were never very common in this part of 'the oul sod', so to get a bike equipped with Zeus is unusual. The bike is local, has been ridden and used judging by the layers of dirt and wear to the parts. Anyway to return to the point, the large flange hubs are not Zeus and turned out to be of Japanese origin. I haven't seen photos of this particular model of hub on the web.

However, here at Methuselah Towers I have a confession to make. I haven't bought a news stand cycle magazine in 10 years and don't frequent internet forums, so therefore cannot claim any kind of expertise other than experience. So I have to defer to the 'experts' on the web, who advocate using various grades of abrasive papers and buffing wheels to polish alloy components. Personally I would have grave reservations about such an aggressive approach, as I have experience of alloy components such as Campagnolo and Stronglight cracking and failing. I also don't agree with re-polishing old alloy to a very high surface shine, far removed from the original finish. To me it detracts from the originality of the parts/machine and can, in my humble opinion, be a case of 'over egging the pudding'.

I prefer a more subtle approach, one advocated by a long forgotten source. I was told to use a brass brush to clean alloy and then wipe the surface with oil. I now prefer to use WD40 or an equivalent solvent, on a soft cloth or a bit of kitchen roll, to wipe the burnished alloy. The brush will get rid of the surface bloom and expose the nature and extent of any surface pitting and corrosion. A decision can then be made about re-polishing if deemed necessary. It is surprising how much the brass brush will clean up the alloy, whilst still leaving a sympathetic finish to the metal. Where the corrosion is not too deep it can be polished out after cleaning, using Autosol and a soft cloth. A final clean with a silicone based car polish will give it the final seal as you have in all likelihood removed the original anodised finish. I have tried to show a few before and after photos to illustrate the point. The Maillard small flange hubs are ones I rescued from the scrap bin of a cycle business. 

Remember that you will need to keep an eye on your repolished alloy as it will now be more susceptible to corrosion as the anodised coating has been removed!