# silver plated circuit boards = purple HCL?



## AJRGale (Jun 6, 2017)

Basically, I had myself some circuit boards, thought I could just remove the silver plated copper off just like i do with the gold plated stuff (HCL bath + air), but the silver seems to have been eaten, and the fluid went purple.

I suspect the purple colour is from the solder that was on the boards, and its just eaten the Silver too, to make it a dark purple.

So, without nitric acid (or only stuff from the supermarket, since Australia), how could I fix this? or what can I do with it?


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## kernels (Jun 7, 2017)

When you say silver plated circuit board you probably talking about tinned copper. The boards probably have a hot-air-solder-leveled (HASL) surface. Since it is Tin and lead it will be consumed by the HCl and yes, I have seen light purple solutions from this.

There is proportionally very little Silver metal in electronics, most of it will likely be in crystals and capacitors.


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## AJRGale (Jun 7, 2017)

well, yeah, i have seen the tinned stuff, that's easy to recognize, its almost a chromish appearance, the silver stuff i had, it was getting tarnished with blackish oxidization look, as you'd expect to see with old silver.

I have a few more of these if you want a picture, and i'll make sure i can identify the tinned stuff as well..

http://i.imgur.com/3zMle1K theres an image of em

left is the tinned, middle is bare copper, right is what i believe to be the silvered coating


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## g_axelsson (Jun 7, 2017)

Silver plate is a modern alternative to tinned boards and a cheaper surface treatment than ENIG. Just as gold it is really thin, I don't see any economical gain from dissolving the copper to get the silver, the cost of chemicals and labor would eat up any meager gains.

The purple color is probably from silver chloride or finely dispersed silver. Purple silver chloride is actually metallic silver reduced to metal by light.

Göran


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## AJRGale (Jun 7, 2017)

g_axelsson said:


> Silver plate is a modern alternative to tinned boards and a cheaper surface treatment than ENIG. Just as gold it is really thin, I don't see any economical gain from dissolving the copper to get the silver, the cost of chemicals and labor would eat up any meager gains.
> 
> The purple color is probably from silver chloride or finely dispersed silver. Purple silver chloride is actually metallic silver reduced to metal by light.
> 
> Göran



Its just an experiment. i thought maybe i could jut take off the plating like gold plating without to much issue.
i have used HCL with buttons off switches to remove the rest of the copper without it going purple.. (unless they were not silver..)

still, is there a way to drop the silver out?


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## g_axelsson (Jun 7, 2017)

There is always a way but if it is easy, cheap or even possible with your limited chemicals is another question.

You can always try to filter it, if it gets stuck in the filter then you have reduced your problem. If it passes through the filter then it follows the copper chloride.

If the silver is colloidal then it might clump together if you dry it out or boil the solution, but it would still be together with the copper chloride. Turning it all back into copper, melting the copper with traces of silver and then run it through a copper cell would place the silver in the anode slime. But to refine it from that slime also takes some work.

Nothing of this is something I have tried and it's nothing I will try either. Silver on copper is basically contaminated copper.

Göran


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## goldsilverpro (Jun 7, 2017)

How did you chemically test this to prove that it's silver?


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## silversaddle1 (Jun 7, 2017)

g_axelsson said:


> There is always a way but if it is easy, cheap or even possible with your limited chemicals is another question.
> 
> You can always try to filter it, if it gets stuck in the filter then you have reduced your problem. If it passes through the filter then it follows the copper chloride.
> 
> ...



Right on, and if it's not, I have a bunch of it for sale.


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## kernels (Jun 7, 2017)

AJRGale said:


> well, yeah, i have seen the tinned stuff, that's easy to recognize, its almost a chromish appearance, the silver stuff i had, it was getting tarnished with blackish oxidization look, as you'd expect to see with old silver.
> 
> I have a few more of these if you want a picture, and i'll make sure i can identify the tinned stuff as well..
> 
> ...



To me that looks like Immersion Tin, not Silver. It has a duller appearance than HASL. Have a look here: http://www.epectec.com/articles/pcb-surface-finish-advantages-and-disadvantages.html

As GoldSilverPro suggested, you want to test for Silver if you really believe it might be. But even then, Silver is closer to a worthless waste product than a precious metal in the quantities you would get from PCBs.


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## AJRGale (Jun 8, 2017)

Well, it was a dull white look with the oxidisation on it, hence where I thought it was silver, not they grayish mirror looking tin, the photo is rather crappy though..

How'd I test? taste test 
Really haven't tested, got nothing to test with, I only assumed it was, and assumed it would work like the buttons I assumed were silver too.

on that note, stannous chloride test wouldn't really work, so I really don't know how to test.

as I said, I expected it to flake off like gold does, and I was able to add it into my silver collection..

like I said earlier, I'm just experimenting, I expect these losses.


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## butcher (Jun 8, 2017)

Stannous chloride can be used to test for silver, but it is not the best.
A little education will save a lot of money and put more gold and silver in your pocket, uneducated gambling your losing gold from your pocket, and with what we are dealing with possibly your health.

Hoke's book has the answers you need. Her book on testing metals goes much deeper into detail than does her refining book, on the subject of testing metals...


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## AJRGale (Jun 8, 2017)

well, bucher, I'm not going to go on here and ask million questions to just get "did you search the forums?"

I searched what I could, and knowledge I have, I attempted this. I expect losses, since I'm only learning.

I look info up, and try it, nothing so far points to the purpling of the HCL, I guessed it was the lead and silver doing it, since the copper is left alone and the rest is eaten..

as for this "Hoke's book" I assume "Refining Precious Metals Wastes" not "Phlebotomy"?

sooo.. nothing yet I can read in it says anything to do with silver in HCL... so I don't think dropping in zinc will drop out the silver..


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## shmandi (Jun 8, 2017)

I don't think there is any benefit of silver on those circuit boards. There are many boards with plating like on your picture, I never even thought they could be silver plated, just tin.


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## AJRGale (Jun 8, 2017)

shmandi said:


> I don't think there is any benefit of silver on those circuit boards. There are many boards with plating like on your picture, I never even thought they could be silver plated, just tin.



the only thing I could thing of is that 0.1% better heat transfer, other then that, its only going to corrode and break connections..

these boards are out of 2010+ Hard drives, so if it is silver, then the connections they use between the heads and the PCB, which are just pressed on by pressure of the PCB screwed onto the chassis, will corrode and cause more and more errors reading data.. unless that Is the idea so they don't have them in service for more then 10 years.. /end'o'paranoia'rant


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## butcher (Jun 8, 2017)

Hoke has a book on testing as well as the book on refining. Knowing how to test for metals will put gold in your pocket and help you keep it there.
Silver salts can change color in light, as the silver salt is reduced to silver by the light. (photography, invisible inks)...
Silver chloride salt can also be reduced (the Silver Cations can gain electrons from sunlight to become elemental silver metal atoms. (normally when less acidic and the insoluble salts are washed and left in sunlight) not a good way to reduce silver chloride in a recovery or refining process because only small portion gets reduced to silver, but great for photography, test papers...


AJRGale, Why the chip on the shoulder? If I suggest study, or reading or at least looking at a book, or doing a search of a topic... I am trying to give you the advice that I believe will be the most helpful.

A few minutes flipping through the book would have answered most all of your questions, and once you read it you will prize it.

Try Hoke's book. You may find it helpful.
PS: Do a search in the book section, also many members had it in their signature line.

PS Silver is pretty much insoluble as a chloride, you will not have silver in HCl to any degree.

PS You have very toxic solutions and salts on your hands now, have you been studying the safety of dealing with these.


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## AJRGale (Jun 8, 2017)

butcher said:


> Hoke has a book on testing as well as the book on refining. Knowing how to test for metals will put gold in your pocket and help you keep it there.



there's 2 books? 



butcher said:


> Silver salts can change color in light, as the silver salt is reduced to silver by the light. (photography, invisible inks)...
> Silver chloride salt can also be reduced (the Silver Cations can gain electrons from sunlight to become elemental silver metal atoms. (normally when less acidic and the insoluble salts are washed and left in sunlight) not a good way to reduce silver chloride in a recovery or refining process because only small portion gets reduced to silver, but great for photography, test papers...


it is purple, it has been purple for a week now, if it was going to change to something else, I have not see it, unless it was meant to get darker, this colour chance has not been clarified.



butcher said:


> AJRGale, Why the chip on the shoulder? If I suggest study, or reading or at least looking at a book, or doing a search of a topic... I am trying to give you the advice that I believe will be the most helpful.


Well, you just told me to look at a book by a Hoke, I know nothing of a book by a Hoke, a little googling gave me more then one answer, as I said, I Assume its the "Refining Precious Metals Wastes"?

I'll give you this, I am new here, saying "hokes book" really didn't help me, if you would of named it out right, even Just once, I would of been OK with it.



butcher said:


> A few minutes flipping through the book would have answered most all of your questions, and once you read it you will prize it.


..and it goes on about Nitric Acid with silver. read the OP regarding Nitric Acid. I have not seen anything in there about purple HCL. 



butcher said:


> Try Hoke's book. You may find it helpful.


PS: Do a search in the book section, also many members had it in their signature line.[/quote] 
talking about the "Refining Precious Metals Wastes" in g_axelsson sig? no notes about this 2nd book.



butcher said:


> PS Silver is pretty much insoluble as a chloride, you will not have silver in HCl to any degree.


hence the original OP, "what have I got, and what is going on" 



butcher said:


> PS You have very toxic solutions and salts on your hands now, have you been studying the safety of dealing with these.


Because of the lead? I have a few litres of that to be processed, but I'm not being stupid with it. I am wearing proper PPE, and containing the remains of what I'm doing, its done outside, since I don't have the proper fume box.


As for this chip on my shoulder, every time I ask something in any forums I get this "Just search it" if a simple search of "Purple hcl/hydrochloric acid" yields nothing, that's where I have to ask, Yet I still get the "Just search it"
I try not to be narky on forums, I'm happy to answer questions, but I just want my questions answered.
even if you treat me like a big dumb goof and link me to another post with the same issue, I may not have see it. ("Hey! Hey goof, look here stupid: viewtopic.php?t=25674" (ok, other people may take offence to that, so "Hey buddy, look here:" may suffice))

So, there is no residue on the bottom of the glass jar od be OK with that), the fluid is dark purple, the silver looks to be coming off the copper, there is nothing left of the solder. so where's the silver? and why hasn't the copper been touched?
I expected the fluid to go dark green/black with the copper being removed, and the silver to drop. if it was not silver, it should of been removed and taken in with the copper and nothing left.
the only think I can think of, is the HCL is not HCL.


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## kernels (Jun 8, 2017)

Geez, back to the start ...

Yes, you have HCl

No, the boards are not Silver Plated

No, HCl does not dissolve Silver or Copper. To dissolve copper you want to turn the HCl into a Copper Chloride etch, commonly referred to as AP.

No, if any Silver did go into solution it would have cemented out on any exposed copper - once again, there likely wasn't any Silver. Immersion Tin has the dull look that you are seeing.

HCl does dissolve Tin and as I have already said, I have had many purple solutions when dissolving Tin + Lead + Nickel

No, it is not just the lead that makes your solutions poisonous, pretty much any heavy metal in solution is far more poisonous than the metal in it's metallic form.

No, on this subject you cannot get a simple answer to a simple question, recovery and refining does not work like that.

Hoke (she) has a few different books, you can certainly start with "Refining Precious Metal Wastes", but there is also a book about Testing precious metals, a quick search gave me this page ->http://goldrefiningforum.com/~goldrefi/phpBB3/viewtopic.php?t=16555

You are fortunate to have people with years of experience give you excellent answers to your questions, you just do not know enough yet to know how good the answers really are.


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## AJRGale (Jun 8, 2017)

kernels said:


> Geez, back to the start ...


wanna be like that? lets go:



kernels said:


> Yes, you have HCl


good to know this bunnins concrete cleaner is HCL..



kernels said:


> No, the boards are not Silver Plated


looks like it may have been.. i have not seen any other boards to look like what I have here, it looks like my mothers old pure silver cutlery when it gets any dirty fingers on it.
every one says its only tin..



kernels said:


> No, HCl does not dissolve Silver or Copper. To dissolve copper you want to turn the HCl into a Copper Chloride etch, commonly referred to as AP.


 just need air/oxygen to get HCL to get the CL to bond to the copper and the Hydrogen bonds to the oxygen. so it should leave me with CuCl and water.



kernels said:


> No, if any Silver did go into solution it would have cemented out on any exposed copper - once again, there likely wasn't any Silver. Immersion Tin has the dull look that you are seeing.



as I have said, and I'll say it again, it looks nothing like this tinned product, that looks shiny like a darker chrome finish. what I have,
http://www.hightechelettronica.com/en/products/fr4-4-layers-kb6160-tg135-immersion-silver/ looks exactly like that. that is the best picture I can find over my crappy image. Just parts of it where dust and moisture got to it had gotten that tarnished look you'd expect on silver cutlery, the tinned stuff, does not have that tarnished look.

Hence my belief it is silver. 



kernels said:


> HCl does dissolve Tin and as I have already said, I have had many purple solutions when dissolving Tin + Lead + Nickel


 I don't want to be picky there, you never said that.
you know, I never even thought about nickel.. would that give a purple look in stannous(basically what everyone is telling me I have)? Hell, lead even?



kernels said:


> No, it is not just the lead that makes your solutions poisonous, pretty much any heavy metal in solution is far more poisonous than the metal in it's metallic form.


well, Butcher made it look worse then what I already expected. I am already dealing with the CuCl and other stuff.



kernels said:


> No, on this subject you cannot get a simple answer to a simple question, recovery and refining does not work like that.


So that's why everyone told be to "read read read," even though I don't know what I'm looking for? hence my questions. I know this stuff isn't easily laid out, hence the 390+ pages in the book. (ignoring the several hundred 5 minute videos that demo these procedures without an issue). but things go outside what is clearly stated, and when they are not included, you have to ask. "I do not know what I am looking at here, I do not know how to proceed, help!" 

but no no, I'm a big dumb goof that doesn't know how to read.




kernels said:


> Hoke (she) has a few different books, you can certainly start with "Refining Precious Metal Wastes", but there is also a book about Testing precious metals, a quick search gave me this page ->http://goldrefiningforum.com/~goldrefi/phpBB3/viewtopic.php?t=16555


Thank you. 



kernels said:


> You are fortunate to have people with years of experience give you excellent answers to your questions, you just do not know enough yet to know how good the answers really are.


so I'm a big dumb goof that doesn't know the wisdom of of experts telling to "Just search".

so, who asked me what I used? who asked me what it looks like? who has told me what my solution highly likely is? who told me to try this, or try that? who asked to "do this to test for silver"
NO ONE
you all just assumed and told me off, and you wonder why I have a chip on my shoulder.


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## anachronism (Jun 8, 2017)

Look. 

Cool your jets mate. If you stick around and get with what the guys are saying to you then within a few short weeks all this will blow over and the sheer amount you can learn here is staggering. Play the long long game I promise you that it's worth it. 

I'm not known for being either PC or backing down when I've got something to say either so don't mistake my comments as a suggestion that you need to kiss butt. I'm just suggesting that a touch of calm would help your cause because let's face it you're in the best place to learn right now. 

Over to you.

Jon


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## chuckgambale (Jun 8, 2017)

I'm impressed Jon. Really spot on advice.


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## butcher (Jun 8, 2017)

AJRGale, At this point, you need to get some understanding, and get started learning.
You are wanting to learn a complicated profession and gain the skill and understanding to work the chemistry of the metals safely.

You are new to this. You have no clue of the complexity, Heck you do not even know the language or even where to begin. I understand your frustration.

When I suggest you study or read, it is because I truly believe that is the best advice I can give you at this point.

As far as safety goes all the PPE in the world cannot protect you, from the dangers involved if you work uneducated.
All the PPE in the world will not protect your neighbors unless you work educated in the dangers and how to deal with them properly. 
The safety section is a great place to begin educating yourself about the dangers involved and how to protect yourself and others around you.

Relax Understand we are trying to help you get started, my suggestions are what I feel will help you the most at this point, each member here will try to help you get started in their own way, with what advice they feel will answer your question or help you get on the proper path to success.

If the solution itself went purple, you may not be dealing with silver at all. You may be dealing with tin and gold in solution, as colloidal gold. If the salts went purple you are most likely dealing with the salts of silver. At this point, all you have is a toxic mess (that I feel you have no clue of how to deal with it to recover any values, or how to safely deal with it).


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## Topher_osAUrus (Jun 8, 2017)

AJRGale said:


> as for this "Hoke's book" I assume "Refining Precious Metals Wastes" not "Phlebotomy"?..



:arrow: http://goldrefiningforum.com/~goldrefi/phpBB3/viewtopic.php?f=54&t=25181&p=266853&hilit=Testing+hoke#p266853

CM Hoke's Testing Precious Metals.
With it, and her Refining Precious Metals book, you will learn a lot. FrugalRefiner also has a link to screen friendly, and printer friendly versions of the latter in his signature line. Just follow the link above.


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## kernels (Jun 8, 2017)

AJRGale said:


> kernels said:
> 
> 
> > Geez, back to the start ...
> ...



Not a single person on this forum is paid to answer your questions. My experience in this forum is that you will get amazing answers if you post a detailed question where you state what the result should be from the research you have done and include high resolution photos.


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## goldsilverpro (Jun 8, 2017)

A question. You say you can distinguish between silver and tin fingers by simply looking at them. Have you ever recovered any silver from those that you have determined are silver? What proof do you have that they are silver? I think "none" will be your answer.

The fingers in the photo you said were silver look like tin plating to me. They have that typical dull gray color of plated tin. Do you realize that silver is the whitest metal on the planet? Also, do you realize that silver readily tarnishes? Do you realize that silver plating on fingers has a tendency to migrate between the fingers and cause partial shorts? In 50 years of working with this stuff, I have never seen silver plating used on fingers, mainly for those reasons. Maybe some foolish company has used it on fingers, but I haven't seen it.


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## AJRGale (Jun 8, 2017)

Alright, I'm sorry everyone, I was being a Prick.

Goldsilverpro: I did say I was only assuming it was silver from what I've learned. 
I did want to know how to test it or a board without nitric acid. I cannot find that in the books.
if its "None" then its "None"
I'll go throw some bleach on it.

(just to add, I'm a visual learner, dyslexic, and I do find 400 odd pages daunting, but I'm the one dealing with that.. although, can you guess how many errors I made typing this?)

kernels: tell you the truth, I signed up back in 2012, since the concept of getting gold off circuit boards caught my interest, i read, watched, read some more, and since then, I've been pulling gold of boards and pins since, I thought I'd see if I could get some silver this time, I am new at this part, I got a result I wasn't expecting, and I got answers I wasn't expecting ether. 

I was thinking people would tell me to try this, or try that, instead I got, "nope, you have this." as I attempted to explain what I think I have, it just seemed like I was getting pushed back, telling me I was wrong without reason.

that's why I was angry about what people were telling me.

Topher_osAUrus, yeah, I have 'em now, thank you.

butcher: I have this stuff on my cereal in the morning, it's making me a strong boy! 

well, I've followed what has been mentioned before, glove up, mask up, get well ventilated.
if you're telling me now the HCL fumes are killing my neighbours, I better tell them to give up their pool, I can smell that over my stuff any day.

I've keep the waste product sealed, if that's not enough, tell me the wiki is lacking in details on managing the waste.. I was going to start looking into dropping the Cu out of it, but I'm still researching. 

..and you're right, I don't know how to deal with this purple stuff, hence why I asked in the 1st place.

I'll point this out again too, its only purple liquid, the copper hasn't been converted to CuCl, the solder is removed, and looks to be the coating on the pads removed. there is no solids within the fluid that I can see.
if you want images of it, ask away. if you want me to try something else: throw hydrogen peroxide in, or Sodium hypochlorite, or Sodium hydroxide, let me know, and what to expect.


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## AJRGale (Jun 9, 2017)

just heads up, its going cloudy, there is metal flakes on the bottom of the jar, and there is also green fluid starting to form where the air has gotten to it.

maybe i should of left it for more then a few weeks instead.


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## kernels (Jun 9, 2017)

Are you able to get some good pictures of the flakes and what you are seeing? Would make it easier to figure out.


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## AJRGale (Jun 9, 2017)

Alright, i'll do that, now its 0046, i'll wait till day time, better then the LED "flash" on my phone.. or find my camera
since "It was not possible to determine the dimensions of the image. Please verify that the URL you entered is correct." sorry for the linkage

http://imgur.com/TVQ4T4e

http://imgur.com/tdvEX6b

of cause it wanted to focus on the trees behind it..
http://imgur.com/4ncxLgt

here's the greening of the fluid with CuCl from the air
http://imgur.com/IJUfpkn

Purple? or orange?
http://imgur.com/qIoRQfM


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## kernels (Jun 10, 2017)

Cool, that is quite purple. When I've had the odd purple solution it was wayyyy lighter than that, more like a purple shine. Was there any gold fingers in that solution ?, if so, Cobalt is sometimes added to improve wear performance of gold. 

If I didn't know better I would think that you have colloidal gold, but you would have to have had some oxidizer in the solution and some gold plating on the boards - and I'm sure you would have noticed if that disappeared. 

I'm inclined to pretty much rule out Silver Chloride, it can turn purplish with sunlight exposure, but it would also settle out of solution after a day or two.


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## anachronism (Jun 10, 2017)

I've not had that colour before and I'm not going to guess! This is a new one on me and I'll be interested to see what it is.

ps Sometimes the simplest solutions are correct- - did you have blue coloured RAM in that batch?


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## AJRGale (Jun 10, 2017)

nope, just gather everything that i thought had silver on it. didn't add any gold stuff in.

the board i thought had silver on it, reacted quickly (under 5 minutes) with bleach, turning it a black colour.
i tested it with another board that look like tinned, did nothing over 30 minutes.


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## patnor1011 (Jun 10, 2017)

And what does that tell you?
Nothing.
Different boards, different manufacturers, different protective layers, different use, age....
There are many methods to test directly for silver so everyone who wants to know can easily find out if the item is silver or not. I stopped presuming long time ago. It usually brought me a headache and nothing else.


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## AJRGale (Jun 10, 2017)

patnor1011 said:


> And what does that tell you?
> Nothing.
> Different boards, different manufacturers, different protective layers, different use, age....
> There are many methods to test directly for silver so everyone who wants to know can easily find out if the item is silver or not. I stopped presuming long time ago. It usually brought me a headache and nothing else.



I tested, not presumed, I told you results, not what I think it meant.
you can tell me what you think these results say, the bleach test is a known silver test, but I did not say it was silver. i only picked out the 2 different types of boards, one I presumed to be silver, and one I presumed to be the tinned did the known test, told the results.

don't take that as I'm telling you its silver, I did it to get the experts opinion.


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## goldsilverpro (Jun 10, 2017)

anachronism said:


> I've not had that colour before and I'm not going to guess! This is a new one on me and I'll be interested to see what it is.
> 
> ps Sometimes the simplest solutions are correct- - did you have blue coloured RAM in that batch?



That may be the answer. I've seen solution colors appear due to the dye in the overlay.


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## g_axelsson (Jun 10, 2017)

The thing that purple color reminds me of is the color you get when dissolving the tin from surface mounted MLCC:s with HCl, what causes that color hasn't been decided either.

Göran


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## AJRGale (Jun 10, 2017)

goldsilverpro said:


> anachronism said:
> 
> 
> > I've not had that colour before and I'm not going to guess! This is a new one on me and I'll be interested to see what it is.
> ...



yeah, forgot to mention, no blue things ether, they were all green, I did attempt to get the coat off with caustic soda, but the cheap stuff has little slugs of aluminium in it for the effect of marketing words of "Fast acting!", so I think it just chewed on that instead.

so yeah, no blue stuff, I could live with that though..



g_axelsson said:


> The thing that purple color reminds me of is the color you get when dissolving the tin from surface mounted MLCC:s with HCl, what causes that color hasn't been decided either.
> 
> Göran



I May not of cleaned off all the surface mounted items, I seen 2 odd SM resistors at the bottom, but to get that much colouring, I need about a cup full if the MLCC yeah?


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