Author Topic: Electrolysis rust removal and stainless steel on the negative  (Read 686 times)

Gattopardo

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Electrolysis rust removal and stainless steel on the negative
« on: January 20, 2019, 04:03:35 pm »
Looking to remove some rust off a few rust bolts and bike bits such as saddle rails and maybe a chain or two.  So can I use stainless steel mesh as the negative bit where the rusty bits sit?.  I have been told not to use stainless as the positive, for that I just have some thin steel bar from b&q.

So will it be alright?

Re: Electrolysis rust removal and stainless steel on the negative
« Reply #1 on: January 21, 2019, 11:31:01 am »
A bit of googling suggests a ss anode (-ve) is fine.
 
See here, post 7.

https://www.model-engineer.co.uk/forums/postings.asp?th=93766
We are making a New World (Paul Nash, 1918)

Gattopardo

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  • Overseaing the building of the death star
Re: Electrolysis rust removal and stainless steel on the negative
« Reply #2 on: January 21, 2019, 03:44:51 pm »
Thanks.

Re: Electrolysis rust removal and stainless steel on the negative
« Reply #3 on: January 21, 2019, 04:28:13 pm »
BTW another thread I saw elsewhere mentioned NOT to try and clean ss this way (ie as the cathode) as one of the products was both toxic and carcinogenic.
We are making a New World (Paul Nash, 1918)

Re: Electrolysis rust removal and stainless steel on the negative
« Reply #4 on: January 21, 2019, 10:07:18 pm »
I would want to be confident what would happen to the chromium from the stainless steel. Solutions of chromium can be toxic and need to be properly disposed off.

Gattopardo

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  • Overseaing the building of the death star
Re: Electrolysis rust removal and stainless steel on the negative
« Reply #5 on: January 21, 2019, 10:47:24 pm »
I would want to be confident what would happen to the chromium from the stainless steel. Solutions of chromium can be toxic and need to be properly disposed off.

That is the thing, as long as the stainless isn't the positive it seems to be alright.  This is a cheap sieve so not sure how stainless is is.

Re: Electrolysis rust removal and stainless steel on the negative
« Reply #6 on: January 22, 2019, 06:58:51 pm »
anodes are +ve not -ve.  Carbon anode seems to be the way to go. 

Some useful info here

http://www.robotroom.com/Rust-Removal-5.html

cheers

Gattopardo

  • Lord of the sith
  • Overseaing the building of the death star
Re: Electrolysis rust removal and stainless steel on the negative
« Reply #7 on: January 22, 2019, 07:56:24 pm »
Always found cathode and anode confusing, as they can be either positive or negative..depending on what you are doing.

Re: Electrolysis rust removal and stainless steel on the negative
« Reply #8 on: January 22, 2019, 10:45:13 pm »
Always found cathode and anode confusing, as they can be either positive or negative..depending on what you are doing.

can they.....? .... :o



Gattopardo

  • Lord of the sith
  • Overseaing the building of the death star
Re: Electrolysis rust removal and stainless steel on the negative
« Reply #9 on: January 22, 2019, 10:57:33 pm »
Always found cathode and anode confusing, as they can be either positive or negative..depending on what you are doing.

can they.....? .... :o

This what I was taught:  The electrode at which oxidation takes place is known as the anode, while the electrode at which reduction take place is called the cathode.




Kim

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Re: Electrolysis rust removal and stainless steel on the negative
« Reply #10 on: January 22, 2019, 11:40:22 pm »
Stands to reason: Consider the electrodes of a rechargeable battery, which change ends at half time.  (Though electronics jibblers tend to only think about their names during the discharge cycle, on the basis that getting the wiring polarity right is more useful than understanding the chemistry.)
To ride the Windcheetah, first, you must embrace the cantilever...

Re: Electrolysis rust removal and stainless steel on the negative
« Reply #11 on: January 23, 2019, 07:53:10 pm »
Anodes are always +ve in an externally  driven electrochemical process (like plating, corrosion removal, or battery charging).

    Strictly speaking yes the oxidation and reduction reactions determine the electrode name and yes that can change the polarity in a  battery-type reaction depending on whether it is being charged or discharged. I see now what you mean by your 'what you are doing'... comment ;)

FWIW there is a third very common circumstance, in corrosion (which is like the galvanic cell above, only without an external load in the circuit); the anode and cathode are at the same potential (they are often different locations on or parts of the same object) and the potential difference that drives the current could be said to exist in the electrolyte/surface material on the electrodes.

cheers