As part of the the running gear refurb for the Mk5 4×4 RS000 I needed to re-zink some of the bolts so thought I would add an article on some of the different methods I have tried over the years to clean parts before dropping them off for zinking.
Electrolysis
This is the process of feeding a DC current through the part you are cleaning creating a chemical reaction. do a quick Google and there are loads of websites and videos with instructions of the different ways to set up your tank and mix in 5 to 10 millilitres of washing soda per litre of distilled water and how to connect your power source.
![](https://i0.wp.com/onemoreford.co.uk/wp-content/uploads/2021/09/Rust-Removal-15.jpg?resize=618%2C464&ssl=1)
After a couple of hours fizzing you can check your part and clean of any oxide with a soft brush and wipe, I used this method for the fan brackets below from my Mk2 Mexico heater box, before building it back up. the pictures below show the bracket after Electrolysis and before re-zinking and after build up.
You can see that if the metal was pitted before it will be pitted after, but once zinked still looks good
![](https://i0.wp.com/onemoreford.co.uk/wp-content/uploads/2021/10/Rust-Removal-1.jpg?ssl=1)
![](https://i2.wp.com/onemoreford.co.uk/wp-content/uploads/2021/10/Rust-Removal-16.jpg?ssl=1)
![](https://i1.wp.com/onemoreford.co.uk/wp-content/uploads/2021/10/Rust-Removal-17.jpg?ssl=1)
Sand Blasting
I also tried a small blasting cabinet as an alternative to Electrolysis, obviously it has a higher set up cost and more abrasive but is a lot quicker and a less faffing about! I’ve not got round to trying different media yet but the results are as good as electrolysis for the bits I’ve done.
![](https://i0.wp.com/onemoreford.co.uk/wp-content/uploads/2021/11/SandBlast-1-1024x576.jpg?ssl=1)
![](https://i2.wp.com/onemoreford.co.uk/wp-content/uploads/2021/11/SandBlast-6-1024x576.jpg?ssl=1)
![](https://i1.wp.com/onemoreford.co.uk/wp-content/uploads/2021/11/SandBlast-4-1024x576.jpg?ssl=1)
![](https://i0.wp.com/onemoreford.co.uk/wp-content/uploads/2021/11/SandBlast-3-1024x576.jpg?ssl=1)
Acid
While the methods above are fine for brackets and larger items they are a bit more of a pain for smaller bolts, washers and screws. For these I have tried a couple of different acids.
Citric Acid
Citric acid is easily available and biodegradable so easy to dispose of when finished. Mix 5g citric acid with 400ml warm water (Can’t say I am very accurate on this bit!) I fill a jar add the bolts and then give it a good shake after a couple of hours.
![](https://i2.wp.com/onemoreford.co.uk/wp-content/uploads/2021/11/DSC06899-1024x576.jpg?ssl=1)
![](https://i1.wp.com/onemoreford.co.uk/wp-content/uploads/2021/11/Citric-Acid-2-1024x576.jpg?ssl=1)
leave it in until the rust is removed, normally leaving it for a few days and also giving the jar a shake.
![](https://i2.wp.com/onemoreford.co.uk/wp-content/uploads/2021/11/After-24Hours-7-1024x576.jpg?ssl=1)
![](https://i0.wp.com/onemoreford.co.uk/wp-content/uploads/2021/11/Citric-2-1024x576.jpg?ssl=1)
![](https://i0.wp.com/onemoreford.co.uk/wp-content/uploads/2021/11/Citric-3-1024x576.jpg?ssl=1)
When the bolts come out they look very black but wash them with clean water, dry them off and brush off the oxide and have a look at the results.
The bolts are a bit pitted depending on the amount of rust they had to start with.
![](https://i2.wp.com/onemoreford.co.uk/wp-content/uploads/2021/11/EvapoRust-5-1024x576.jpg?ssl=1)
![](https://i0.wp.com/onemoreford.co.uk/wp-content/uploads/2021/11/Citric-7-1024x576.jpg?ssl=1)
![](https://i1.wp.com/onemoreford.co.uk/wp-content/uploads/2021/11/Citric-8-578x1024.jpg?ssl=1)
Distilled Vinegar
No mixing for this one and nice and cheap! just fill the jar with distilled vinegar to cover the bolts and leave them, I tended to leave for a good few days like the citric again shaking every now and then and end with a wash and brush. Results to my eyes seemed better than the Citric acid but not much in it.
![](https://i2.wp.com/onemoreford.co.uk/wp-content/uploads/2021/11/20210320_171444-492x1024.jpg?ssl=1)
![](https://i2.wp.com/onemoreford.co.uk/wp-content/uploads/2021/11/Rust-Removal-6-1024x576.jpg?ssl=1)
![](https://i0.wp.com/onemoreford.co.uk/wp-content/uploads/2021/11/Rust-Removal-3-492x1024.jpg?ssl=1)
![](https://i2.wp.com/onemoreford.co.uk/wp-content/uploads/2021/11/Rust-Removal-9.jpg?ssl=1)
![](https://i0.wp.com/onemoreford.co.uk/wp-content/uploads/2021/11/Rust-Removal-4-1024x498.jpg?ssl=1)
Evapo-Rust
Been reading a few articles that say this stuff is better than the different acids for rust removal due to not removing metal once he rust has gone? But it costs a lot more than a bottle of distilled vinegar! but thought I would give it a try. Same process as before soak in a jar, until the rust has gone and then a good rinse in clean water and a wire brush to remove any oxide.
![](https://i2.wp.com/onemoreford.co.uk/wp-content/uploads/2021/11/DSC06901-1024x576.jpg?ssl=1)
![](https://i2.wp.com/onemoreford.co.uk/wp-content/uploads/2021/11/DSC06907-1024x576.jpg?ssl=1)
![](https://i1.wp.com/onemoreford.co.uk/wp-content/uploads/2021/11/EvapoRust-2-1024x576.jpg?ssl=1)
![](https://i2.wp.com/onemoreford.co.uk/wp-content/uploads/2021/11/EvapoRust-1-1024x576.jpg?ssl=1)
![](https://i0.wp.com/onemoreford.co.uk/wp-content/uploads/2021/11/EvapoRust-7-1024x576.jpg?ssl=1)
To test I did 3 of the front subframe bolts in Evapo-rust and 3 in citric acid soaked for the same time 4 days
The ones done in Evapo-rust are below on the left, Citric acid on the right and I think the winner is the Evapo-rust! Will see how many bolts I can do with this current bottle and see how it work trying to reuse a couple of times. If the rust is not that bad I would use the distilled vinegar.
![](https://i1.wp.com/onemoreford.co.uk/wp-content/uploads/2021/11/Citric-Right-1-1024x576.jpg?ssl=1)
![](https://i2.wp.com/onemoreford.co.uk/wp-content/uploads/2021/11/Citric-Right-3-1024x576.jpg?ssl=1)
Another tip from doing this test, these subframe bolts are a bit bigger and managed to crack both of the glass jars I’ve been using for smaller screws for ages while giving them a shake! so have upgraded to some plastic paint tubs from Wilco’s, Lots better!!
![](https://i0.wp.com/onemoreford.co.uk/wp-content/uploads/2021/11/DSC06970-1024x576.jpg?ssl=1)