Citric acid derusting

[Turbo]

Going to go and get a plastic bin with a lid to decant that 20kg bag of citric into before I bust the bag open, may get a chance to try it tomorrow

Bob

Be careful the bin doesn't bust, they're not made to be filled with water! I managed to bust a couple of trugs by filling them with water!

 

[SierraV6]

Some comparisons here:

Removing Rust - Australian Wood Review

Rust is the enemy of fine woodwork, but there are ways of winning the war.

www.woodreview.com.au

Thanks, I’ll use up what I have and then try citric instead I think!

 

[JMS1972]

First attempt at Citric acid. 4 table spoons of powder kettle full of boiling water and about the same cold.

Before

During

After an overnight soak, rinse will distilled water, red scotchbrite and wd40.

Pretty pleased with the results the pliers were locked solid and now work fine and I was gutted when the Mitutoyo combination square succumbed to the dreaded rust should be usable now.

 

[The_Yellow_Ardvark]

First attempt at Citric acid. 4 table spoons of powder kettle full of boiling water and about the same cold.

Before
View attachment 299466
During
View attachment 299467

After an overnight soak, rinse will distilled water, red scotchbrite and wd40.

View attachment 299468

View attachment 299469

View attachment 299470

View attachment 299471

Pretty pleased with the results the pliers were locked solid and now work fine and I was gutted when the Mitutoyo combination square succumbed to the dreaded rust should be usable now.

Warm wax will be your friend now

 

[Onoff]

A while back I scored a number of mixed make storage bins inc some original Linbins. Most won't clip to modern louvre racking but will at least stack one atop the other. The contents long gone or rusted away, some bins have cracked and they were destined for the tip.

I used the best, all the same ones after a quick jet wash and was left with others, some with lots of rust staining in the base.

I've dunked these and washed with a plastic scourer / Fairy Liquid, then hosed off. I figure citric acid might shift the rust. Off to the shed!

 

[Onoff]

So...a tsp full or so in each bin and hot water from the kitchen tap.

Seemed to start lifting the rust straight away.

Might not work but at least it'll give SWMBO something to moan about. "What's THAT doing in the kitchen?"

To think I've a lovely, freestanding stainless sink including the frame scored years ago. Just need a nice workshop to go around it.....

 

[JMS1972]

Citric works well on limescale encrusted toilets too.

Before (don't judge )

After several soaks in citric and warm water.

Just a few loose bits which haven't flushed yet. A bit of agitation with a loo brush or old dish brush helps break it up

 

[ronan]

Citric works well on limescale encrusted toilets too.

Before (don't judge )

View attachment 300111
After several soaks in citric and warm water.

View attachment 300112
Just a few loose bits which haven't flushed yet. A bit of agitation with a loo brush or old dish brush helps break it up

You need to eat more fibre !

 

[Onoff]

Citric works well on limescale encrusted toilets too.

Before (don't judge )

View attachment 300111
After several soaks in citric and warm water.

View attachment 300112
Just a few loose bits which haven't flushed yet. A bit of agitation with a loo brush or old dish brush helps break it up

A few squirts of WD-40 down the pan works well. Straight into the water. Leave overnight.

Ditto pour a litre bottle if the cheapest full fat cola down there.

 

[Rkweld]

Has any one else used malt vinegar, sorry if it a double post, trying to get up to speed with some threads. I had good results with it on corroded pressure welding dies after salts got into the tempering process after not being thoroughly cleaned after hardening. Sat them in a small tub and kept them warm, with a make shift lid that didnt pressurise to stop too much evaporation.

 

[Seadog]

@hermetic has used home-made cider vinegar

 

[droopsnoot]

I had a go with normal supermarket vinegar and didn't get much in the way of results - not as much as I expected given the before-and-after photos on the site I read about it on. And, it really smells.

 

[Seadog]

Vinegar can be between 5% and 9% acetic acid. I think that white pickling vinegar may be the stronger of the two, but don't quote me on that. I mix my own from concentrated acetic acid (99.9%)

 

[a111r]

Has any one else used malt vinegar, sorry if it a double post, trying to get up to speed with some threads. I had good results with it on corroded pressure welding dies after salts got into the tempering process after not being thoroughly cleaned after hardening. Sat them in a small tub and kept them warm, with a make shift lid that didnt pressurise to stop too much evaporation.

I used to use it to good effect, cleaning up rusty vintage pushbike chromed parts. Takes longer than citric as it's weaker acid.

 

[The_Yellow_Ardvark]

Has any one else used malt vinegar, sorry if it a double post, trying to get up to speed with some threads. I had good results with it on corroded pressure welding dies after salts got into the tempering process after not being thoroughly cleaned after hardening. Sat them in a small tub and kept them warm, with a make shift lid that didnt pressurise to stop too much evaporation.

Yes.
Good for light surface rust.
Heavy or pitted rust, no.

 

[SierraV6]

Are you meant to add salt to vinegar (I don’t mean on chips!)? It seems counterintuitive but I’m sure I read somewhere that it increases the effectiveness.

 

[Ross365]

Are you meant to add salt to vinegar (I don’t mean on chips!)? It seems counterintuitive but I’m sure I read somewhere that it increases the effectiveness.

Adding salt may speed things up, but I would never do it. There's nothing better than salt for initiating corrosion of steel than the chloride ion (as in sodium chloride) and you can wash your stuff as much as you want, but water alone will struggle to get 100% of the chloride off. The rust is much less likely to come back if you leave the salt out.

Citric is more powerful than acetic, but unless you can recall what you were told about "molarity" at school, the detail gets complicated.

 

[Turbo]

Are you meant to add salt to vinegar (I don’t mean on chips!)? It seems counterintuitive but I’m sure I read somewhere that it increases the effectiveness.

If you are using it to clean up corroded brass/copper electrical terminals like car multi plugs the salt helps the process but you must neutralise it afterwards with a water rinse followed by a baking soda solution rinse & a final water rinse.

 

[Rkweld]

I had quite good results with it removing scale from salt bath hardening and tempering. That was neat shop bought malt vinegar and gentle warmth over night. Foamed but the heat was not excessive as it was only in a plastic container. It may be a different story with heavy rust. It was more for making the dies more pleasing to the eye without having to excessively grind them after.

 

[SierraV6]

Adding salt may speed things up, but I would never do it. There's nothing better than salt for initiating corrosion of steel than the chloride ion (as in sodium chloride) and you can wash your stuff as much as you want, but water alone will struggle to get 100% of the chloride off. The rust is much less likely to come back if you leave the salt out.

Citric is more powerful than acetic, but unless you can recall what you were told about "molarity" at school, the detail gets complicated.

If you are using it to clean up corroded brass/copper electrical terminals like car multi plugs the salt helps the process but you must neutralise it afterwards with a water rinse followed by a baking soda solution rinse & a final water rinse.

Thanks both that's useful to know.