Rust Removal Experiments: Citric Acid, Cider Vinegar, Rostio 

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.

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. :-)

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.

Good video. I usually use Baking Soda mixed with Water to neutralize any acid that I use to clean rust off of metal. Works great for Citric Acid. Then rinse with water, dry and usually spray down with WD40 to stop flash rusting.

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.

Some additional remarks: Could I have chose a different kind of vinegar? Yes. Could I have chosen a cheaper kind of vinegar? Yes. Could I have performed the same experiments with about a hundred other substances? Yes. I really just picked some of the various substances that were recommended to me by the viewers. This is just a smaller project that is only a means to an end and stuff like this often just needs to get done in the shortest time possible. An experiment with molasses rust removal will be shown in a future video. There also could be more extensive tests using all kinds of substances in the future, but I want to finish the lathe restorationj and the EDM project first.

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.

This restoration is getting really impressive, congratulations !

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

I've used citric acid numerous times in rust removal purposes. As a joiner, I mostly use it to derust hinges and so on in windows and doors. Anyways, citric acid doesn't eat the iron too much nevertheless if you use it for more longer period of time. When derusting tractors or cars, just add gypsum or plaster and "paint" it to somewhere. About neutralizing, just wash with water and dip in thinner. Citric acid is used in agricultural so big bulks are available for cheap batches. Propably the _best_ rust removal method for every day use! My favorite method :p If there's paint. Just make batch of water and lye and paint-be-gone for one day, next day just wash with water and submerge in citric acid. Wash with water and dip in thinner and after that just paint or oil the parts and that's all to it. Best way, and cheap!

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

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

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.

Thank you for your video. It was very instructive. You have a great command of the English language. Your information was presented clearly and easy to understand. Very well done!

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.

Thanks for this little overview, though only a couple things apply here in the states. I have been restoring some old car parts made out of steel and it's good to know what I should use. It's also really interesting to see what old tools you have, and what odd things you have found. Personally, I'd like to see a video detailing some of the stories of some of those odd, 100+ year parts you have.

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.

Thank you. That was very informative.

nice video man. very useful. i'm just cleaning an old shed full of old rusty gardening tools. this will hep me a lot. keep it up! best regards from Croatia.

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.

Klar,deutlich und sehr erbaulich!Danke!

Very nice . I enjoy all your videos . Thank You Sir. Keep up the great work. This will definitely help me in the future.

Thanks for this. I'm just about to clean some old planes myself and bought liquid Rostio to do it. I'll try the citric acid method now first, because the Rostio was 20 EUR per litre. Thanks for sharing. Very well done, well structured and explained very clearly.

An excellent video. Very logical and also informative.

interesting video series. Thank you for your hard work!

chemical reaction info : my Nexus tablet( maybe most other have these) has a translation icon . Great video and thanks for the hard work .

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 RU-vid 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.

Thank you for another informative video. My comments may be 3 years late, but for what they are worth ... The gelatinous rust remover product used in California is called Naval Jelly, and its counterpart for aluminum corrosion is Aluminum Jelly. I have not used either, and don't know their chemical base. Most of our liquid commercial rust removers are based on phosphoric acid, which works very well and leaves the metal looking black . I commonly use vinegar, or acetic acid which is equally effective in the white or distilled form as cider vinegar. Since white vinegar is used as a cleaning agent, it is much less expensive, never more than $3.00 per gallon. You can afford to use it in quantity. I have only recently learned of using citric acid, as it appears to be popular in European countries and Australia. I don't intend to change, as the white vinegar works and is inexpensive. I have concluded that any of the common weak acids work as rust removers. Some may be less reactive than others, but what does that matter? Most of us are happy to leave parts soaking overnight, and when you consider the bulk of the tool, a little extra corrosion is negligible. These are weak acids and the metal they will dissolve is far less than that taken by the rust itself. Of course nitric, sulfuric, or hydrochloric acids in concentration would be a very different matter.

well thought out and well explained...very interesting

I would love to have that Mauser adjustable wrench!! Awesome video!

Sehr interessant! Das sind alles sehr gut gemachte Videos, wir freuen uns vor allem über mehr Elektronik in den Beiträgen :)

Excellent video, very comprehensive

the videos you do are cool and interesting thanks for the uploads

Super Darstellung - und nebenbei: hervorragendes Englisch!

Excellent Video!

I used vinegar a lot. Cheaper stuff, meant for cleaning. I will try citric next time i need to get rid of rust. Nice review!!!

Good job!! Keep doing the good work!!

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."

I enjoyed watching this. Thank you sir.

I'm really looking forward to the rest of the lathe restoration.

Great video, thank you for sharing your results :)

Thanks, very interesting. Keep on trucking ! (from France)

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

I have 3 brands of rust remover on my shelf, all of them have phosphoric acid as the active component. It has a distinctive smell you can easily recognise once you know it.

Love your videos

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

Hi TPAI, Good information, video. As you may know , the 3 jaw chuck jaws come out 1, 2, 3, and, of course go in 3, 2, 1. Good job on the Lathe restoration. Be good, C.

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.

Thank you, for the great Video. Test it again with heating the water. It works much better!

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!

I've had a lot of luck with a phosphoric acid based CaCO3 remover gell. But that was for removing rust from an enamelled surface. "Apfelessig" is a great word... I love German "compound-words".

Just to share some info with you: I have been using citric acid off ebay (because cheap) to derust motorcycle tanks from inside. I have the impression that a surface should first be degreased (I use dish soap and water) and the loose rust removed (I use small SPAX screws and a cement mixer). After that, rust removal works quite well just as you described. concentrationwise I use 200g/L when I work at room temperature and 20g/L when I can heat up the solution to about 80°C. Note that the warmer the solution, the less concentration can be achieved, but the faster it "chooches", as AvE would say. If I wash out the tank with tap water after derusting I have found that the surfaces flash rust immediately. Since then I use acetone or isopropanol to wash out the tank after derusting. I have not yet found a homebrew DIY way to passivate the surface after succsessfully derusting it.

Thank You. I been thinking of doing something pretty soon.

With the gelatinous removers I've seen people pull out a layer of plastic kitchen wrap, lay the work piece on that, slather it in the jelly and then roll it up, pressing the plastic up against the surface and sealing it into a little rusty jelly package. Helps counteract the dripping effect.

If you live close to any Polish shop, I would recommend using the Polish vinegar for de-rusting as it is 10%, not 5%. I leave the metal in the 10% vinegar overnight and with a little help of a wire brush, even the heavy rust comes right of :)

Very interesting will give it a try thanks

Great video thank you. I used Coca cola when I was a kid to get rust off my bike. Worked really well. It has phosphoric acid in it.

Rostio is likely comparative to 'Naval Jelly' by Loctite here in the US. It's main active ingredient is phosphoric acid and it's gel form w/brush.

We have a similar saying in the UK " There is more than one way to skin a cat " lol. I always enjoy your videos, keep up the good work !

Cool! The jelly-type remover looks similar to "Naval Jelly" but not the same color

For the jelly, use plastic wrap to keep the jelly tight against the item.

Nice job. Danke!

Hard to beat the electrolysis method; the catalyst is never consumed, the reaction won't attack the iron, and it's fast.

how would you compare the chemical versus the electric rust removal methods, in terms of efficiency/cost/effect? Great videos, thanks.

Nicely made video! Looks like the Rostio product kinda sucks. I mean that part on the lathe would have been less than 5 minutes with a reusable wire wheel on a drill motor. Like you, I have found chemical rust removal kinda limited. I use acid to clean the inside of rusty steel tanks(where you can't get inside to scrub). These are usually air tanks that weren't drained regularly. I fill the tank with an acid solution and put a more rusty piece of metal in a cup of the same solution. When the part in the cup looks pretty good, I figure inside the tank is. I empty and flush the tank with water. I then put a bunch of moth balls in the tank with a pint or two of 91% isopropyl alcohol and turn the tank over and around, using the moth balls to scrub the inside from agitating the whole thing. I drain this out and do the same thing with about a pint of mineral spirits (by itself, no moth balls). When I drain this out, I pour in about about a Quart of oil based paint and turn the tank over and on all sides many times to thoroughly coat the inside with paint. I remove my plugs and drain the excess paint and then let it dry overnight. I have done this a number of times with good results. I don't own a bore scope but have used a friends and found really great results. This also works good for mildly rusted fuel tanks. For very rusty fuel tanks, there is a special product for coating the inside, using the same method. I hope you find this useful. Take Care and be safe, John

When you do the molasses, please address the sulphured vs unsulphured. thanks.

Elektrochemie ohne Stromquelle: Die rostigen Teile in Salzwasser mit Aluminiumfolie abreiben. Die Alufolie oxidiert, das Eisen reduziert, der Kontakt sichert die elektrische Verbindung und das Salzwasser die Ionische Verbindung. Somit ist der Materialabtrag minimal und die Teile hast du vermutlich zu Hause. Bei dicken Rostschichten dauert das allerdings sehr lange - also am besten den groben Rost abtragen und dann rubbeln.

That black iron 3 oxide coating following citric acid bath is protective against further oxidation. I've used it as a protective finish with good results. Black oxide (common name) is a coating used on drill bits, tools and other ferrous metal products.

Thank you for sharing

I was thinking of this video this past weekend when I was buying some old rusty tools at an antique store. I'll send pictures of the results if you are interested.

It depends on what I'm trying to get the rust off however I normally use for the heavy stuff a large container filled with hydrochloric acid at 40% strength, and that works well for the really heavily rusted items, for the next down the list sulphuric acid at 24% and for the light stuff I use vinegar at only 7%.

If Rostio is like the naval jelly we have here in the states it's phosphoric acid based

Rusteo is phosphoric acid in a gelatine substrate. Think I will try the organic acid treatment on some rusty tools, Might at least get it free enough to run again, though I have little hope. But have a lot of vinegar around, used to descale kettles, and I use another acid to clean aluminium piping inside.

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

Electrolysis with some vinegar added works well for me and is prettly fast. A quick soak in Hydrochloric acid first for anything heavily rusted.

great info.

the rust removing gel I have some of a different brand the trick is to use cling film over it to hold it in place and to get right thickness

I don't know if anyone has said it yet but the american equivalent to rostio is naval jelly which is made from Phosphoric acid there are also rust converters that are made from tannic acid

Here's a method I use on cast iron pans with great success: put your oven into "self-cleaning cycle" and lock the piece in there for the several hours your oven needs for self-cleaning. When it's done, the piece will be covered in fine powder that brushes off to reveal clean bare iron. No chemicals or elbow grease necessary.

It would have been interesting to see the finish on the dividers if you had used a much finer steel wool. You used what I call pan-scrubber steel wool. 000 and 0000 wool might have given you a much cleaner finish. Nice work, interesting experiment. Thanks

I found phosphoric acid worked very well, though did attack the iron a little. apparently though the iron phosphate it leaves behind has corrosion inhibiting properties. It would be interesting to see how quickly the parts you have cleaned to rusty again from any trace chemicals left behind in the metal.

Very good video... Seems like citric Acid is a good choice.

welldone video!!

As you say in Germany, "There are many ways that lead you to Rome" As we say in Wales, "There are many way to skin a cat" Thanks for the video BTW. Very interesting and informative.

I've had good luck with "Drano" drain cleaner (in crystal form) which is mostly Sodium Hydroxide. I put several gallons of water in a plastic container.. add the Drano and then leave the (iron) parts overnight. It will turn aluminum parts black.. so you might not want to dip those. I have yet to try heating the water to see if it is more effective. For more information on Drano, Wikipedia has an article on the product.

Sehr informatives Video! Daumen hoch!

I was wondering why a corrosive acid like acetic acid can be used to derust ferrous metals. thanks for the explanation!

That's funny that you have a similar saying about Rome as we do in English (I've noticed that most sayings are culturally specific). Our saying goes: "All roads lead to Rome". But it's basically identical

EXCELLENT.

Rostio is just phosphoric acid jelly. the best result I have got so far was with oxalic acid, although it takes very long time compared the phosphoric acid.

vinegar is great to remove rust BUT the real trick, as you learned, is the timing. If you over hold it, the acid will eat into the metal. I assume that is because the rusted metal is already weakened at the surface so what I do is check it ever 3-4 hours and make sure I time myself to place an item in vinegar only if I am able to take it out and clean it no more than 12 hours if I cant check every 3-4 hours. Great videos, thanks for sharing.

I've seen vinegar used as a cheap metal prep on car panels when getting ready to paint.

Rostio's active ingredient is sulphamic (NOT Sulphoric ) acid. It is also sold as LimeAway and Lime light in UK. You will find that if you dissolve it in water and then use it in a similar way to that of Citric acid it will be faster. It is also much safer than Hydrochloric acid other in that it does not release noxious gases and is safe to release in public drains

Some rust conversion occurred on the cog, leaving the black residue (a good thing).

German guy speaking English (American English), German accent, German cadence, some German syntax, excellent vocabulary, excellent diction, idiomatic expressions are plentiful and accurate and used properly.......language proficiency is excellent. Where and how did he learn to speak English......so well.......? ? ? ? ? ? ? Best regards, fm

You could also try phosphoric acid that you can get cheaply by buying PH- products meant for pools.

in the US we say, "there is more than one way to skin a cat." ;)

Thank you

If you go to oriental food shops, they often sell the citric acid pretty cheap.

I know I might be late, but you can hear up the water to speed up the reaction. I do this with my boiler. I put some vinegar and turn it on, and keep it between the temperature hot, but not boiling. Within a minute all the spots are gone. But if you put vinegar instead of lemon juice it will smell!