Rust Removal Experiments: Citric Acid, Cider Vinegar, Rostio

A video about using citric acid, cider vinegar and "Rostio" for rust removal purposes.

background info for the chemical reactions (in German):

[Steffi]

Holy cow, that vintage lathe you showed at the end looks so art deco, so thirties. From a time when even steel tools were made not to just work, but to be beautyful as well.

[martinda]

I really enjoy your videos. Your voice has an interesting effect on me. I hope you don't mind me saying... It cheers me up a lot, partly because it amuses me. It is a lovely voice, with a gentle and musical lilt - but it makes me smile.
What is as important as the wonderful delivery though, is the content and the information conveyed to the viewer, and this is of excellent quality too. Thank you for great entertainment. From one of your British fans. :-)

[EmperorDevilhunter]

I use destilled vinegar which is stronger (8º) and cheaper (0.50€/liter). You can make it work faster by heating it by the way.

[andypughtube]

I have had very good results with 10:1 diluted molasses.
It takes weeks, so falls outside your parameters, but it is both gentle and very effective.
It allows you to treat rather large parts at reasonable cost and at the end you have sugary water, not hundreds of litres of acid.

[shanevonharten]

20 minutes on some old lightly rusted spanners, excellent results. Thank you.
Seen people use fish tank heaters to keep the water warm which speeds u the process.

[smjones]

I use a plastic centrifugal pump from an evaporative cooler to recirculate the liquid in the tank. Works really well for the electrolysis, would probably help for citric acid as well. Only uses a few watts of power. Speeds up the process/makes the process more uniform. Great set of videos as usual.. Michael in Colorado.

[leekronforst]

Thank you for giving those of us who haven't been exposed to the metric system enough to understand it right of the top of the head the information in gallons.

[halvaargniberg]

egal ob alte oder neue Videos, sie sind alle extrem sehenswert
Danke

[Cyberpuppy]

Great showcase. You show real examples, and you include details needed to ensure good results (ie pre soaking and wire brushing before using a chemical solution). Critics might complain "But that's not showing power chemistry!". I didn't notice the aluminum risk, but I'll re-run the vid to try and spot it.

[aford]

You left out some info regarding your experimentation and I don't agree with you 100% on your conclusions, but this was my own take from my use of various methods of rust removal for Model A Fords and other makes. You didn't mention putting your clear plastic tray out into the direct sunlight. I can tell you that the process of rust removal works much better when that is done. Most of my parts are left outside for anywhere from a couple of hours to 3-7 days, with no real issues over any metal loss at all. Flash Rusting is the main culprit, but a lot of folk have cleaned up Model A carbs and left them on their shelves for years afterwards with no significant flash rusting noted. Oiling the part immediately after a water rinse seems to be the best result to stop the flash rusting, but if appropriate, painting or priming the part is also helpful.Apple cider vinegar is okay, but you can increase the acidity of the vinegar and there are YouTube videos on how to do that.  However, a better medium in my opinion is dry molasses which I generally use in my mix at a 4-5 scoops per gallon of water. Nothing else is required and this mixture can be poured into a flower bed with no problems, but I would not do so into a vegetable garden. It is a sludge mix after just a few hours and the odor is not too great, but it works very well for rust removal. Although I also use various mixes as my electrolysis mixture, the problem for electrolysis is all the equipment required. The vinegar or molasses mixture just requires mixing the brew, inserting the parts and then putting the clear plastic bin outside in the direct sunlight. The Texas hot sun does a wonderful enhancement to this process.I also frequently use a plastic kiddie pool to handle larger parts as fenders or engine block parts. They are cheap and easy to find for such a project.I am assuming that the Ristio is essentially the same as naval jelly and I have had little satisfaction with the use of that product over the years. Lye or Red Devil is easier to mix in water and use, but these chemicals are caustic and to me, dangerous If you have animals or kids about. Pool acid works, but it too is highly caustic, allows for more fumes and is a total danger to pets or kids when not supervised closely. The fumes from such can also entrap other metal items if left uncovered in a hot garage or such. I did that once with a Model A I was working on in my garage and got called away. I had pushed the open container of pool acid under a workbench thinking I'd be right back. Well, I forgot about it and it was about 3 days later when I opened up that garage. Everything inside the garage had flash rusting on any part which was not protected by paint. Over $10, 000 in damage to that Model A, as even the chrome on the bumpers had turned into an ugly green goo and flaked off. Virtually every screw,  nut and bolt was rusted over on that Model A Ford and it taught me a grand lesson in using acid of any kind to clean up car parts or other metal objects. Do not leave it unattended and in an enclosed area.I also had a unique experience with a bunch of screws I had put into a metal sieve and dipped into a vat of lye. The acid quickly ate the metal sieve away and dropped all the screws, nuts and bolts down to the bottom of the vat. Again, the lesson is to learn what the product may do to various types of metals and don't leave the mix unattended. It does not hurt to check the progress of any dip often, but the length of time the part is in a bath is likely not to ruin it by any real metal loss of significance.  If a part still has rust after the bath, you can use stock oven cleaner and a wire brush to remove any additional scale. Even a quick once over with a sand blast medium can easily remove any residual rust the mix does not remove.Me, I prefer the dried molasses mixture over any of the products you use in your experimentation. It is cheaper and works every bit as well and often better than citric acid and such. These parts may develop a darker color once the mix brew is doing it's work, but most parts will ultimately be primed, oiled or painted anyway, so that is not a real issue.I am not knocking your experiments at all, but I have used these same products for over 40 years and this is what I feel about their use. My results are not experiments,   but tried and true methods which worked best for restoration projects on vintage autos. As I said, you left out the idea that this mixture works best when used under the hot sunlight, but it sure does.  Thanks for posting your results.

[divyajnana]

Thank you for the informative video. You can 't imagine how many videos are on YouTube that DON'T give the mixture ratios!!! Thank you, Thank you, Thank you.

[mikekollross]

To use less liquid put the part in a ziplock bag, pour in vinegar and squeeze out the air. Then submerge the bag in water. You get total coverage for way less liquid.

[neiloconnor]

Vielen Dank. Most commercial rust removers available in hardware stores have phosphoric acid as the active ingredient. In English speaking countries, this product is referred to as 'Naval Jelly.' Most hardware stores will also sell 30% acetic acid vinegar as a cleaning agent. Combined with table salt, it's an effective rust remover, and good at polishing copper, bronze and brass. Both of these products are caustic, and generate slightly dangerous fumes. Thanks for mentioning the hydrogen gas, and further oxidation of the metal. The dark or black residue is FeO, which can be wiped off. For smooth surfaces, such as saw blades, I recommend using a paste wax as opposed to a machine oil. The wax won't attract dust and moisture, which lead to further rust. I will view your electrolysis experiment. Amazon accidentally sent me a spare packet (250g) of citric acid, which will now be used for rust removal. As my Bundeswehr roommate in Bosnia once advised me, "Zweimal messen, einmal schneiden."

[rutgerssander]

Very informative, thanks for going into rust removal with so much detail. This is definitely going into my "keep" drawer!

[AutodidactEngineer]

I think that for normal people it's best to use citric acid as shown in the video!
I have recently bought an old vise which is caked in rust, I will also be zinc plating it through electrolysis.
These videos are a gem to us DIYers!

[xandrasa]

Endlich mal einer, der grammatisch richtiges, elaboriertes und gut ausgesprochenes Englisch spricht.

[silkytp]

The best rust removal product is called Naval Jelly. It's sold it he US, and was used for years on the rust that formed on navy ships. It's basically phosphoric acid. You paint it on, let it set, then wash it off

[thedowntownbikeshop]

Great video!

Evapo-rust! I use it for bike parts. Non toxic. I like that you pointed out dealing with parts you can't submerge.

[grunthostheflatulent]

guten Tag! Thank you for your informative videos. Having worked in an electroplating shop for 10 years, I have restored multiple vehicles and engine parts using such resources. By trial and error, I have found that the solution didn't exist in cathodic / anodic cleaners or just straight acid / caustic reactions -- the secret to my success was the ultrasonic cleaner in a citric acid / soap solution. This offers no Hydrogen embrittlement issues (quite serious) and also if you add a brass part to the UC, the part will have a thin coating of Cu on the cleaned areas - ready for a flash coat of Cu or Ni to prevent further rusting.

As a chemist, I'm very much impressed by your knowledge about the reactions going on.
Thumbs up 👍