Cheap rust removing solution

[Sonic EscapeParticipant @sonicescape38234]

I found this stuff in the supermarket. It is an acid based toilet cleaner, 20% hydrochloric acid. It is by far the most effective rust removing liquid I tried so far. This is the result after only 6 minutes:

And it only costs 1 euro! Same result I got with concentrated vinegar after a few hours. Impressive.

[FulmenParticipant @fulmen]

I really can’t recommend hydrochloric acid for this use. Sure it works, but it’s also good at causing rust on everything else around. A safer choice would be sodium citrate: https://www.youtube.com/watch?t=1&v=fVYZmeReKKY

[Fulmen]

On Fulmen Said:

I really can’t recommend hydrochloric acid for this use. Sure it works, but it’s also good at causing rust on everything else around.

Yes, I’m afraid you are right. I used these pliers to cut the bottle cap. And look how it looks after a few hours!!! It didn’t even come into contact with the liquid. Just from the vapors I think. The pliers were like new before…

[FulmenParticipant @fulmen]

There you have it. And yes, it’s the vapors. Hydrochloric acid is quite volatile and will leak out of any container. In old laboratories it was always easy to see where the acids where stored, anything metal around it was always corroded.

[SillyOldDufferModerator @sillyoldduffer]

What Fulmen said, plus Hydrochloric Acid leaves Chlorine ions in the pores of the metal.  They remain active underneath paint, powder coatings and electroplate causing them to puncture and peel off after a while.

Best cheap rust remover is Sulphuric Acid if you can get it.    Many countries control sales because baddies use it for acid attacks, dissolving corpses, and making explosives.

Caustic Soda and electrolysis is a good alternative and legal everywhere!

Dave

 

[Sonic EscapeParticipant @sonicescape38234]

Too bad, it was very effective at removing rust. I’ll stick with concentrated vinegar or citric acid. They have about the same effect, but they take longer to dissolve the rust.

But what if I keep the bottle of acid in a ziplock bag? And I only open it on the balcony. And can’t the residual chlorine be neutralized with something?

[larry phelan 1Participant @larryphelan1]

Could be useful for mixing with your Mother-in-law,s drink ???

[larry phelan 1]

On larry phelan 1 Said:

Could be useful for mixing with your Mother-in-law,s drink ???

but after that I’ll have to make sure she doesn’t stay near my tools.

[CirclipParticipant @circlip]

A neighbour decided to clean his hand sheep shearing clippers in said “Drain cleaner”. In less than five minutes he was left with just the spring top, the Carbon steel blades being eaten into uselessness. BEWARE.

 

Regards  Ian

 

 

[CirclipParticipant @circlip]

To the moderators, Are all my postings subject to Moderation? Wearing thin when trying to give sensible answers quickly

 

Ian

[JasonBModerator @jasonb]

Yes, thats is what you get for making non sensible posts.

[bernard towersParticipant @bernardtowers37738]

does no one use evaporust?

[JohnFParticipant @johnf59703]

I found this some time ago, not tried it yet but looks interesting ?

Rust Remover (Better than EvapoRust) – YouTube https://www.youtube.com/watch?v=fVYZmeReKKY

John

 

[Sonic Escape]

On Sonic Escape Said:

…

And can’t the residual chlorine be neutralized with something?

Not cheaply!  A microscope reveals even highly polished metal-surfaces are pitted and scratched, leaving plenty of space for micro-contamination.  Cleaning Hydrochoric Acid residues needs a penetrating chemical that dissolves deeply embedded molecules.  I guess the object would have to sprayed in a vacuum chamber and then boiled in a bath.   A complicated expensive process, not put together using bits and bobs sold by Lidl!

Ferric Chloride is corrosive enough to dissolve Copper – it’s used to make printed circuit boards! Rust removing Sulphuric Acid leaves much less corrosive residues and they can mostly be washed out with water.    Always dangerous to say never, but industry don’t use Hydrochloric Acid as a rust remover.  And Sulphuric Acid isn’t idiot proof – concentration and time both matter.

Though Model Engineers often like chemical folk remedies, they rarely compete well with properly tested professional products.

Another example.   Molasses is often recommended as a rust remover, and it might work well.  Certainly doesn’t have serious unwanted side-effects!  Unfortunately molasses exists in many different forms, it isn’t a single well-defined product that always does a good job removing rust.  The stuff sold in the UK for cookery is too expensive and refined to remove rust.   Cattle feed molasses works, or not, depending on the sugar refining process used to make it.   As does the stuff sold for horses.   Hit and miss, try it and see.

For removing rust, it seems crude acidic molasses of the cheapest possible kind is best, but that variety is probably only available where sugar is made from cane rather than beet.  Texas, not Norfolk!   And because crude molasses is likely to be processed depending on industrial needs, what Joe Public gets as “Molasses”  s a gamble.   So recommending molasses for rust removal is unreliable, unless it’s explained where others can buy the same one.

Good fun experimenting with potions though – just don’t jump too quickly to conclusions.

Dave

 

 

 

[Russell EberhardtParticipant @russelleberhardt48058]

Top of my supermarket hydrochloric acid bottle after a few months storage:

DDefinately not good to keep near tools.

Russell

[Robert Atkinson 2Participant @robertatkinson2]

The Backyard Balistics formula is basically make your own monosodium citrate. This is a recognised chelation agent. You can buy monosodium citrate (E331 food additive) for les than the ingredients used for making your own. I don’t know if a little bit of free citric acid helps with the diy method.

Robert.

[noel shelleyParticipant @noelshelley55608]

Not sure it removes rust but 5% phosphoric acid will convert the oxide to insoluable phosphate. Noel.

[BazyleParticipant @bazyle]

remember to de-grease first or you get patchy results. Store outside in child and pet proof box.

Citric acid is normally available as dishwasher and kettle descaler. You don’t need food grade and it is safe to handle and use in the kitchen or near children. It is sometimes suggested that you ‘damp it down’ by adding washing soda (calcium carbonate) to make a buffered solution. NOT caustic soda – drain cleaner- as it aggressively attacks skin.

For electrolysis mentioned above use washing soda NOT caustic soda.

Phosphoric acid is the best amateur cheap compromise. It can be used quite weak and apply by brush not dunking for best economy. After 5-20 minutes wash it off  or leave for hours and it produces a crusty deposit and stains the workpiece but can be re-cleaned. It is available as swimming pool neutraliser and is hand safe in those formulations. Often the suppliers are resellers watering it down for more profit. My quick access jar actually keeps increasing in contents as it absorbs moisture. The dilution doesn’t seem to matter.
Sometimes Cocacola is suggested – this is because it used to contain phosphoric acid.

These agents are not a substitute for elbow grease – you must make the effort to remove all rust you can first.

After washing and drying on a good job you will see it quickly (2-5 minutes) darken as a fine new rust film forms. So as wuick a possible treat with well diluted clear Waxoyle car underbody treatment. This is much more user friendly than oil. Also soft candle wax (not car polish) can be used on hand and woodworking tools.

[DalboyParticipant @dalboy]

If buying citric acid from a chemist you maybe asked a few questions, as there are some very naughty people using it for making nasty drugs.

I got questioned the last time I brought some

[Nigel Graham 2Participant @nigelgraham2]

I bought my last bottle of citric acid in an ordinary chain household emporium without question!

It is effective, too. Not ever so fast and you do need remove as much rust first by, e.g. wire-brush, then degrease the workpiece.

My last use for it was cleaning some neglected taps and dies I had recovered.

[Sonic EscapeParticipant @sonicescape38234]

I Romania I bought 4kg of citric acid 100%, in powder form. Also no questions, and quite cheap. How do you make that nasty stuff from it? 😁

[Robert Atkinson 2Participant @robertatkinson2]

Bazyle,

I suggest you view the Backyard Balistics youtube video linked to earlier.  Adding Sodium in the form of carbonate, bicarbonate or hydroxide doen’t “damp down” the citric acid. It converts it to monosodium citrate. This is a different chemical and removes rust by chelation.
Use of plain phosphoric acid requires great care as it will consume the base metal. The commercial phosphoric acid based rust converters include corrosion inhibitors to prevent this in normal use.

Robert.

[BazyleParticipant @bazyle]

My mistake was that it is p,otassium not calcium, I was trying to cover the topic without mentioning chelation which has become a magical mystery term for the advertising department in rust removal. Phosphoric acid in the dilutions advised is relatively benign like vinegar and does not damage the workpiece when brushed on for a short time as I recommended.

[Author]

Posts