Electrolysis Confusion

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DSBradley

Member
Hello, I have a question about electrolysis and how the metal moves. Everything I've read doesn't really answer the question outright but suggests that the metal moves from the pan to the sacrificial steel. However, some talk about the metal builds on the pan from the sacrificial steel. If the first statement is true, I can see how everything is cleaned from the pan but not why the sacrificial steel is named the way it is. Sacrifice usually means losing, not gaining. If the second statement is true, then that means all the carbon and rust is just plated over but the name then fits the sacrificial steel. :shootself: :???: :???: :headpop:

I'm one of those "need to know" types.

Thanks in advance :covri:
 
Others may tear me up here, but this is my impression:

It is a trade. The negative charged atoms migrate to the positive and the positive charged atoms migrate to the negative. In the electrolysis case, neither are attached permanently to the other. With chrome plating, the positive attaches permanently to the negative.

I use rebar for the sacrificial electrodes and the CI has a black coating when cleaned that washes off. That black coating is iron. Meanwhile the rust is sitting around and lightly attached to the sacrificial electrodes and can be washed off too.

Hilditch
 
I only use ss as sacrificial and my skillets have black coating too,I don't know exactly how the current flows but,what I sure it only flows one direction.it is like welding on DC if you inverse polarity you will have a lot of splatter.the positive acts like magnet.
 
I haven't visited this forum in a while, and saw this thread. Iron, steel, cast iron, and carbon rod are all acceptable Anodes, however, the use of Stainless Steel as an anode is a know hazard, as it contaminates the solution with Chromium.

Pre Vince Falter, respected Model A authority:

I do not recommend using a stainless steel anode due to the decomposition and toxicity of the Chrome released in the solution.

Here is a link to his Electrolysis article:

http://www.fordgarage.com/pages/electrolyticderusting.htm

Darryl in Fairbanks
 
Let me be the first to correct myself. We are dealing with molecules, not atoms. Thanks all y'all.

Yes the DC current only flows one way, from the + to the -. It will break loose molecules at each end, as well as in the bath (bubbles). The loose molecules are then subject to magnetic forces which get them to trade places. Not all of them make it and end up in the bath. Like chrome, which does not take a good magnetic charge. Chrome plating takes a special bath. SS is still mostly iron.

Hilditch
 
W. Hilditch said:
Let me be the first to correct myself. We are dealing with molecules, not atoms. Thanks all y'all.

Yes the DC current only flows one way, from the + to the -. It will break loose molecules at each end, as well as in the bath (bubbles). The loose molecules are then subject to magnetic forces which get them to trade places. Not all of them make it and end up in the bath. Like chrome, which does not take a good magnetic charge. Chrome plating takes a special bath. SS is still mostly iron.

Hilditch
Click to expand...

Electrons actually. Conventional thinking was for DC to flow from positive to negative - in reality, it's negative to positive. When you see the math behind it, they use conventional but it really doesn't make a difference.
 
Now you are confusing me Rob. I was talking about the movement of rust and iron molecules, not electrons. Then you start talking about lightening. In our simple electrolysis bath there really is only a one way current which affects both pieces. It does not go the from negative to positive any more than a two mile electric fence reverses it's charge direction. From positive to negative. Let's keep it simple.

Hilditch
 
W. Hilditch said:
Now you are confusing me Rob. I was talking about the movement of rust and iron molecules, not electrons. Then you start talking about lightening. In our simple electrolysis bath there really is only a one way current which affects both pieces. It does not go the from negative to positive any more than a two mile electric fence reverses it's charge direction. From positive to negative. Let's keep it simple.

Hilditch
Click to expand...

Sorry... It's not confusing at all. When talking about currents, "conventional" anode to cathode is generally what is assumed - and that goes way back to when electricity was discovered. Conventional however is wrong when talking about current - but mathematically, it doesn't matter.

Current in reality flows from negative to positive. When you have your anode and cathode in the electrolytic solution and turn the power on - current flows from the piece you're cleaning to the sacrificial iron. Current isn't doing the damage. It is what it is. This is the reason you have to clean your sacrificial iron, it gets dirty right?

However, it's the "ions" from the sacrificial iron that travel in solution from the positive to negative. Once ions start leaving metal for example, it gets "eaten".
The electrolyte solution is the ticket here. Not easy to find a diagram that works.

electrolysis-revision-17-638.jpg
 
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