yellow/brown electrolyte?

[jcbarton]

Hello, It seems that even though I am using supposedly distilled water (I am located in central america) my electrolyte (KOH) quikly turns from clear to a radiator coolant looking yellow to a bright orange or brown. Does anyone know what is causing this? I use SS cups that I know are probably of poor quality but they do not attaract a magnet so I know that they are true SS. I also am aware that 316L is the best to use but I have limited resources due to my location. Any ideas? I think it is the cheap metal or I am getting ripped off with fake distilled water..

[SmartScarecrow]

Hello, It seems that even though I am using supposedly distilled water (I am located in central america) my electrolyte (KOH) quikly turns from clear to a radiator coolant looking yellow to a bright orange or brown. Does anyone know what is causing this? I use SS cups that I know are probably of poor quality but they do not attaract a magnet so I know that they are true SS. I also am aware that 316L is the best to use but I have limited resources due to my location. Any ideas? I think it is the cheap metal or I am getting ripped off with fake distilled water..

in my own setup, I do get a very slight discoloration in the fluid ... not much but its there ... in particular when I first fire up a new device it is most noticeable ... once the device has "broken in" the discoloration is still there but is less noticeable ... by most standard I hear in this forum, my solution is very weak as I typically use 20-40 grams of KOH per gallon of distilled water ...

if the discoloration in your fluid is really severe, you might be getting a chemical reaction with some plastic, glue or oil you left in the device ... best thing I could suggest is that you clean it up really good with soap and water, then rinse very well, reassemble and try it again with fresh fluid ... see if the problem is reduced ..

the yellow/brown stuff is normally iron oxide (rust) that is being yanked from the steel ... in almost all cases is caused by inferior quality steel ... but obviously if that is the steel you have to work with, that is what you must use ... so try to eliminate the other possibilities (glues, oils) and see if you can improve the situation ... if not, dont worry about it ... the iron oxides look nasty, but will not contaminate your solution like some plastics and oils will ...

[Painless]

I've had the same issue with the 304L plates that I use. The brown leached material was the death of my last cell, youy mauy recall my pictures SSC.

I have found that a larger gap reduces the leaching and discolouration.

Russ.

[Q-Hack!]

Another possibility is your plate/cup configuration. If your voltage per plate gap is too high, then you will get the discoloration you describe. On a 12v setup you need +|||||- to get your plate gap voltage down to 2V.

Or in your case:

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