It goes without saying that these are difficult times for all with the Covid-19 virus spreading throughout the world. As a result, the farm is mothballed and we await the return of better times. We are still carrying out maintenance tasks, but the majority of our time is being spent at home and so our attention turns to all those tasks that are at the bottom of the list and never seem to get done. So here is a wee blog about one of those, controlling rust, something different to our usual content!
Anybody who works with the sea shall tell you that it is absolutely ‘murder’ on your tools, and we are no exception. Due to the nature of what we do we use a lot of tools on the farm, from simple hand tools like knives and wire cutters all the way through to pull lifts and small water pumps. All of these suffer from exposure to salt and corrode relatively quickly; trying to maintain the tools in good working order, and rust free, is a constant battle.
While fixing broken lines this winter several of our shifters got badly abused and this resulted in them becoming completely frozen with rust, including my favourite Bahco. A good few hours were spent with file, oil and rag, trying to bring these back to life but with no result. These tools were too good to throw away, so it was onto the internet to see if anybody had any ideas we could use to try and get rid of the rust.
While trawling the usual suspects sites we came across electrolysis. This stirred vague foggy memories of secondary school chemistry. I was intrigued and so decided I just had to give this a go, if nothing else it would pass a few hours.
In brief, electrolysis is:
Electrolysis is the passing of a direct electric current through an ionic substance that is either molten or dissolved in a suitable solvent, producing chemical reactions at the electrodes and decomposition of the materials.
Electrolysis [can be] used in the cleaning and preservation of old artefacts. Because the process separates the non-metallic particles from the metallic ones, it is very useful for cleaning a wide variety of metallic objects, from old coins to even larger objects including rusted cast iron, cylinder blocks and heads when rebuilding automobile engines.
Rust removal from small iron or steel objects by electrolysis can be done in a home workshop using simple materials such as a plastic bucket, tap water, lengths of rebar, washing soda, baling wire, and a battery chargerhttps://en.wikipedia.org/wiki/Electrolysis
Disclaimer: If you want to follow what we did then you do so at your own risk. It is stating the obvious, but this experiment involved electricity and water which are a potentially dangerous combination. There are also risks with the release of hydrogen gas and with using different types of metal, in particular stainless steel. Before starting do your research, a good primer is to be found here.
There are various approaches that can be used but we decided to use the basic approach in this YouTube video.
Here is our equipment list:
- Plastic storage box
- Battery / trickle charger
- Ionic solution
For 5, following the advice of Ken Sweden in the linked YouTube video, I went with his approach, and instead of using washing powder, I used a salt and vinegar solution. That is per 1 litre of water, 1 teaspoon of salt and 37ml of vinegar. See the video for an explanation as to why he prefers this approach.
Each shifter was left them in the electrolysis bath for between five and eight hours. When you first place an item in the bath you shall know it is working because almost immediately you shall see small bubbles form around the negative electrode (your tool). This is hydrogen gas being released from the chemical reaction. You shall also see that a charge is running at the battery charger. If the bubbles are missing or there are very few, then it is likely that there is a poor contact on the electrode. We filed an area on the shifters where we attached the wire to ensure there was a good electrical contact for the circuit.
By the way, if your tool starts to get eaten away and the sacrificial piece of metal (point 4) does not then you may have the electrodes wired the wrong way round. The positive (red output) needs to be applied to the sacrificial piece of metal, and the negative (black output) needs to be applied to the tool.
I was amazed out how quickly the surface rust started to come off. Quite quickly the bath water becomes cloudy with particles. Funnily enough after a while you can see an outline of the tool in the surface of the fluid. I would assume that this is something to do with the gas being released.
So turning to the results, how did it go? Well remarkably, really well. As you can see from the pictures I was able to recover all three of the shifters and they are now all fully functional again. I was delighted to recover the Bahco shifter, my favourite, as it is a high quality tool. The others are lower grade quality tools but they still do the job and it is good to have them back in working order. All in all, a mini success, a triumph for science!
I think if I re-designed the setup so it was more in line with Ken Sweden’s setup the time may have been reduced and I may have got even better results.
So now we have recovered our shifters and learned, or is it relearned, a wee bit of chemistry. Electrolysis is a great way to strip of the rust and it was remarkable easy to setup. So sometimes it is good to have a bit of time on your hands…