Citric Acid

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Marsh

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Hi All, When using Citric Acid as a descaler, what is the best percentage mix? Should the water be hot or cold?
Thanks in advance Marsh.
 
I just use it cold, and have no idea of the percentage, I just mix some up so it works. The main problem with brass is that it will leave copper patches on it if left too long. Maybe I'm doing it all wrong, I would also like to know what others are doing.

Paul.
 
I use it hot and have no idea what the concentration is. Works good but parts need a rinse in fresh water after.

Dave
 
I just use straight white vinegar and rinse with water. Don't leave steel parts in to long or it will pit it.


Ron
 
Marsh,

I use warm water, adding the citric acid crystals whilst stirring until no more crystals will dissolve in the solution.

Use it until the cleaning action gets really slow. I have some mixed in my shop that is over a year old and it is a filthy colour, but it is still working.
You should find that you can leave components in the solution for ages without any damage being caused. I have had some forgotten in the bottom of my tank for months, and they came out perfect.

It won't burn your hands or make you glow in the dark, or any other wives tales, just take normal precautions as when handling any metal bearing solutions, thin rubber gloves are ideal, followed by a good washing in clean water, in fact, when newly mixed, add a bit of sugar and feed it to the mother in law as lemonade.

I have found the best thing to remove the copper "staining" that usually appears when silver soldered parts are pickled is to use a brass wire brush in my Dremel.

Hope this helps

John
 
Update to an old post. Citric acid is a marvelous descaler. A ready source at the grocery is "Lemi shine". In the dish detergent aisle. Acids strip tin and such from brass and bronze, so limit your solution to a PH Of no less then 4. It will take a little longer but still does a great job. Litmus test paper will check that for you.

Have fun, be safe!
 
Litmus paper does not indicate pH , it will show acid or alkali , for pH you would need to use an indicator paper or drops . Citric acid will not strip tin from brass or bronze , but why would there be any tin there ?
A strong alkali such as caustic soda is far more effective at removing tin or lead coatings (if there was any).
 
Citric acid will not strip tin from brass or bronze , but why would there be any tin there ?

Because of the basic elements in almost any Bronze alloy, Copper and Tin?
Edit -
They don't mean strip a surface coating, they mean strip it out of the alloy itself.
 
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