Electro question 2: can the electrolyte be filtered to clean it

[Lewis Downey]

Hi,

I am a bit ahead of myself here, but can the electrolyte be filtered and cleaned?  This is sort of a two-part question, apparently lye is both a better electrolyte and also highly recommended as a pre-electro treatment. All of that makes me wonder why not use lye for the electrolyte. You know, two birds with one stone.

I read on this forum that washing soda buffers the electrolyte and is therefore less finicky in terms of mixing up the solution. Then I started wondering about emptying the lye bath to check the anode or replace it -- which led me to wonder if some kind of filtering set-up would keep it clean and minimize the number of times that the  lye needed to be removed. I guess if you have a separate lye bath you can be working on more pieces at one time.

Lye vs washing soda is secondary to my actual question: can you filter the electrolyte to clean it?  I am imagining a continuous pump-and-filtering process that runs while the electro is doing its thing.

Or is that a bad idea?

[Cheryl Watson]

Ah... Ah.. Lewis.... I am the Queen of overthinking!!

Mind Meld....  ;D ;D

so.... Stop and Think strategies are in order.

The electrolyte can be Lye or Washing Soda.

I have chosen Washing Soda for Safety Reasons. <conservative here>

The Washing Soda can be pumped out with my handy dandy submersible pump as grey water to the ground.

Lye goes into the Lateral for Annual "Clean Out" of the lateral week or two. (Maybe spaced out to every two years, now that I have my HDPE barrels)

I use Lye for initial de-gunking.

Electro to get at that oxidation.

Washing Soda it CHEAP.  I dump it and replace as needed.

So... why worry about recycling the gunk from a Lye Bath (with all that extra  to the Electro?? or vice-versa.... 

Right Perry?   ;D ;D ;D

[Mark Zizzi]

Lye goes into the Lateral for Annual "Clean Out" of the lateral week or two.

*scratchin head* what?  :-? lol

[C. Perry Rapier]

Ah... Ah.. Lewis.... I am the Queen of overthinking!!

Mind Meld....  ;D ;D

so.... Stop and Think strategies are in order.

The electrolyte can be Lye or Washing Soda.

I have chosen Washing Soda for Safety Reasons. <conservative here>

The Washing Soda can be pumped out with my handy dandy submersible pump as grey water to the ground.

Lye goes into the Lateral for Annual "Clean Out" of the lateral week or two. (Maybe spaced out to every two years, now that I have my HDPE barrels)

I use Lye for initial de-gunking.

Electro to get at that oxidation.

Washing Soda it CHEAP.  I dump it and replace as needed.

So... why worry about recycling the gunk from a Lye Bath (with all that extra  to the Electro?? or vice-versa.... 

Right Perry?   ;D ;D ;D

You are absolutely correct Cheryl. I agree 100%. I was goin through all that in my mind and I had to stop and sit down and rest for awhile.

Fellas this lady knows what she is talking about. She'll tell you this, I taught her a lot of what she knows.

BUT, she has since left me in the dust. She's the 'Queen of Clean'.  :)

[Jeff Friend]

Lewis,

To answer your question, yes, you can filter your electrolyte solution, but it would be a big hassle.  Since there are dissolved and particulate solids that build up in the bath, I think the "operator" should do something to occasionally remove them.  My suggestion is to let the liquid sit for a day, which will allow the solids to settle to the bottom of your tank.  Then, using a piece of pipe with a few feet of flexible hose attached to it, siphon out a few gallons with the pipe at the bottom so it picks up the settled solids.  You can let the solids settle in the collection bucket and return the liquid to the electo tank, or just send it all to the sewer authority.  My suggestion is to just get rid of everything you've siphoned out because it will purge both the dissolved and particulate solids out of the electrolyte solution.

Now, for your two birds with one stone question.  The "one stone" can be sodium hydroxide (NaOH), but the "two birds" are different concentrations of NaOH - one for electro, one for the lye bath.  The electrolyte solution that uses NaOH is much more dilute than the lye bath a piece is soaked in to chemically convert the baked on grease to soap and other crud that can be washed off.  You could run electrolysis in a lye bath, but the concentration of NaOH would be too conductive for a 12 volt system.

For what it's worth, I stopped using sodium carbonate a long time ago.  Sodium hydroxide keeps the pH a little higher and the anode (I use stainless steel) lasts longer.  At the low concentration of NaOH that is needed for electrolysis, I don't consider it being significantly different than sodium carbonate from a safety standpoint.  The real safety issue is the higher concentration of sodium hydroxide we use in the lye bath.  One final point - neither sodium carbonate or NaOH buffer the solution.  The pH you get after dissolving the material is what you get.  As the solution gets weaker, the pH will change.  I don't think one is less finicky than the other.

Cheryl's lateral is the sewer line from her house to the street.  If you have the municipal sewer option, that is the best way to dispose of used cleaning solutions. 

[Lewis Downey]

Jeff,

You answered *exactly* what I was trying to ask. Thank you very much! Since you did such a great job and since apparently no good deed goes unpunished, I have a follow-up question.

For a power supply I picked up a used bench power supply  capable of outputting 0 to 16 Volts DC and 0 to 10 Amps DC.  I liked the size as compared to a large battery charger and also plan to use it to power a hotwire foam cutter occasionally. Hopefully I found an device that will work for both.

<still noodling over two birds and one stone...>

Does the adjust-ability of the bench power supply make it feasible to use a stronger NaOH solution as the electrolyte?  If the solution would be too conductive for a 12-volt system, would it work fine if operated at a lower voltage? BTW, I am really glad you mentioned that; I might have mixed up a lye bath level of concentration and fired up the  system.

I am not opposed to a separate lye bath, but I am curious about this detail.

[Jeff Friend]

Lewis,

The more conductive the electrolyte solution, the lower the voltage you need to push the electrons through the circuit.  Remember, voltage is analogous to pressure.  You probably will need to watch what you're doing so you don't exceed the 10 amp capacity of your power supply.  If it doesn't have an internal fuse or breaker, you could install one yourself somewhere in the output circuit just for protection.

Since you're still noodling over the two birds, think of it this way.  Let's say you have an electro setup that allows exactly 10 amps to flow at 12 volts with a certain pan and 10 amps is the rating for your power supply.  This current flow is what you measure when electrolyte solution contains 1 lb of NaOH in 20 gallons of water.  If you start adding more NaOH, the conductivity of the solution will increase, so its resistance will decrease.  More electrons can flow since the pressure (voltage) has not changed, so your power supply is now putting out more than 10 amps.  Maybe 20 amps.  If the current exceeds the power supply's rating, something in the power supply is going to fail.  It may take a while, but eventually something has to give. 

With an adjustable output voltage, you can change the voltage so the current flow is always about 10 amps, regardless of the conductivity of the electrolyte solution.

Jeff

[Cheryl Watson]

Lye goes into the Lateral for Annual "Clean Out" of the lateral week or two.

*scratchin head* what?  :-? lol

As Jeff clarified:

Lateral = main sewer line that runs from the house, out to the street and the MAIN line.

My cleaning station is set up 2 feet from one of the exterior, clean outs, on the lateral.

In prior years, I emptied my lye baths for the Winter, as I was afraid that the freeze and thaw cycles would CRACK the Rubbermaids.  This year, my new plastic barrels are staying filled.

When emptying lye baths, I would drain them thru a siphon with running fresh water to dilute by 50%.  I would drain 1 lye bath, and then wait 1-2 weeks to drain the other. 

Since learning that sodium hydroxide is used in the Sewage Treatment process, I will probably quit worrying about putting too much in at once... :)