# Silver testing in spent photo fixer



## a_bab (Mar 22, 2010)

Hi, I'm new here. 'Been lurking for quite a while, and now I have a question: there's one very simple method for silver testing involving a simple copper wire, credited to Juan Manuel Arcos Frank: 

If the wire gets silvered in ------- Silver Concentration 

1 second-------------- 12 gr/lt 
2 seconds------------- 10 gr/lt 
3 seconds------------- 6 gr/lt 
4 seconds------------- 3 gr/lt 
5 seconds------------- 1.5 gr/lt 


Now, my question is: what does "silvered" means? What color should I look after? 

Thank you.

PS: I'm working on a method involving cadmium sulphide (as in silver strip testing). I'll detail it once it's fully tested.


----------



## goldsilverpro (Mar 22, 2010)

> Now, my question is: what does "silvered" means? What color should I look after?


The pink copper will become silver colored.


----------



## a_bab (Mar 22, 2010)

Mine seems to get black rather then silvery. Hmmm, copper sulphide? And I definately have silver in there.


----------



## Barren Realms 007 (Mar 22, 2010)

a_bab said:


> Mine seems to get black rather then silvery. Hmmm, copper sulphide? And I definately have silver in there.



The silver is black when it plates onto the copper!!!!!


----------



## goldsilverpro (Mar 22, 2010)

I've tested the silver in fixer 100s of times, with copper wire or pennies, and have never gotten a black deposit. It is always silver colored or gray.


----------



## Barren Realms 007 (Mar 22, 2010)

goldsilverpro said:


> I've tested the silver in fixer 100s of times, with copper wire or pennies, and have never gotten a black deposit. It is always silver colored or gray.



Sorry, gray then. 100% agree.


----------



## Juan Manuel Arcos Frank (Mar 23, 2010)

LOL!!!!!!!!!!....Credited by me?....no way...I just posted it.

Before I was borned,GSP was already using this method !!!!!.He has posted the method to make those expensive yellow silver test papers using sodium sulphide.

If the copper wire gets black means that there is no silver.Silver plated or grey color means that there is silver in solution.

Regards.

Manuel


----------



## goldsilverpro (Mar 23, 2010)

> Before I was borned,GSP was already using this method !!!!!.He has posted the method to make those expensive yellow silver test papers using sodium sulphide.



I didn't originally post that. I thought you did. I think you can easily make those Kodak test papers by soaking filter paper in sodium sulfide solution, letting it dry, and then cutting it in strips. However, since those strips are yellow, maybe they are cadmium sulfide instead of sodium sulfide. All you need then is one of those handy-dandy Kodak color charts to tell you how much silver is in solution. There's probably one on the internet somewhere.

Maybe the black forms from some copper from the wire and some sulfide that is formed from the S2O3. Copper sulfide, like a_bab suggested.


----------

