Electrochemistry Sulfuric cell not working

[Wingedcloud]

Hello everyone,

A while ago, I decided to build a sulfuric cell to remove the gold plating from various pins (motherboards moslty) I have acess to.

It's not high value material, but I have it for free, so why not get it?

Anyway, I got all of the materials necessary to build the cell, which is shown below.


I already have some copper mesh to make my basket, but I started with that copper sheet to make some tests to make sure it all worked fine.

The problem I am encountering is the following: I put my material in the copper sheet. The material consists of the pins shown above, some pins from fiber CPU and other gold plated items from e-scrap. Some items deplate just fine, but others dont' deplate at all.

My battery charger reaches 0 and I still have the plated items intact.
The sulfuric acid shown in the picture is almost new. It is not spent for sure. My electrodes are in good condition too, in my opinion.
I really have no idea why there are some items that do not deplate. Truth be told, I have no deep knowledge and understanding on this process, so I have no idea of what I might be doing wrong.

Hope you can help me with your knowledge.

Kind regards,

Winged

 

[patnor1011]

What is concentration of your sulfuric acid?

 

[Wingedcloud]

What is concentration of your sulfuric acid?

My acid is 98%.

Winged

 

[Findm-Keepm]

You may be creating a faraday shield, blocking the current from getting to your plated items. This can occur with mesh or a solid tray -

Search the forum for "faraday shield" and you'll see some solutions - most involve making sure the tray/mesh basket sits lower than the lead slug.

Cheers,

 

[FrugalRefiner]

Is your charger a "manual" type? I've read that some "automatic" chargers will shut down prematurely.

Dave

 

[goldsilverpro]

0 and 1 what?

 

[Wingedcloud]

You may be creating a faraday shield, blocking the current from getting to your plated items. This can occur with mesh or a solid tray -

Search the forum for "faraday shield" and you'll see some solutions - most involve making sure the tray/mesh basket sits lower than the lead slug.

Cheers,

Thank you Findm. That seems a very nice explanation. I will make a new, deeper basket with my copper mesh and see if it solves the problem.

Is your charger a "manual" type? I've read that some "automatic" chargers will shut down prematurely.

Dave

What do you mean by "manual" or "automatic" ?

0 and 1 what?

I did not write 0 and 1 GSP. I wrote "0 and I". Very easy to make confusion, though

 

[jason_recliner]

I think this is your problem:

I have no deep knowledge and understanding on this process, so I have no idea of what I might be doing wrong.

Powerful, concentrated acid mixed with electricity is not something to be guessed with. You're trying to follow a recipe and are already substituting parts of the design. Instead, you should have a comprehensive knowledge of the process, including how it works, before you begin.

That said, based on the info provided I'm inclined to concur on a combination of BOTH the charger and the faraday shield. Many automotive chargers "switch" to zero rather than taper off the current as a constant voltage source (e.g., a battery) would. You've not said what the starting current was, nor how rapidly it returned to zero.

 

[Long Shot]

Winged - automatic and manual refer to the control function of the charger. Many modern ones are "self regulating" thus automatic and work by charging the battery in controlled stages. Not sure, but I think this is to make sure the battery doesn't get boiled dry (this happened at our shop when one of the young lads left our charger on a vehicle in manual overnight and it wasn't pleasant ). Using a battery charger as a cell power supply is not it's intended use and to use it for this purpose it must be a manual model. I got my 2 amp from a flea market for $12 - it is old school and I don't know if you can get a small manual model these days. My experience with these new ones indicates they are junk regardless - seem to be designed to self destruct after short usage.

When you say some items don't de-plate what are they? You mentioned fiber CPUs - my understanding is that the items must be in electrical contact with the copper plate or mesh for the magic to happen so is it possible these items are not making contact? My studies also agree with the remark that the lead must be above the copper level or no go.

 

[Wingedcloud]

Hello everyone,

I'm sorry for the delay on the response to your advices, but I haven't had the chance to come to the forum sooner.
I found Findm-Keepm's reply to hold most of the answers to my problem. By making a quick inspection of my eletrodes, I could notice that they were more or less at the same level, so I proceded to make a new copper basket, this time using the copper mesh I had.
I then added a couple of plated pins from fiber cpus and other ones I had, and it began to deplate right away !
I had to give it a quick swirl to put the non-deplated pins in contact with the mesh, and they were done
So I guess the problem wasn't on the battery charger, although the needle sometimes get stuck, giving an incorrect reading, and that is something I need to try to solve.
So, thank you very much Findm-Keepm, jason and Long Shot for your constructive replies, which helped me quite a bit

I think this is your problem:

I have no deep knowledge and understanding on this process, so I have no idea of what I might be doing wrong.

Powerful, concentrated acid mixed with electricity is not something to be guessed with. You're trying to follow a recipe and are already substituting parts of the design. Instead, you should have a comprehensive knowledge of the process, including how it works, before you begin.

I am a creature that needs practice in order to learn. I can't stand reading non-stop and then try something. I need to put what I read in practice and, most of the times, make a mistake, in order to come back and look for an answer. That's my fuel, that's what keeps me wanting to move forward and learn more

Winged