Question about gold plated pins

[mythen10]

I recently purchased 125 Siemens industrial PLC boards, the kind they use to run automation equipment. The boards that had Cpus on them had 386 and 486 processors so they have been around for a while.

All of the boards had at least 2 and some had 3 or 4 IDE type connectors on the boards (see photo 1). On normal type boards I would use a steel putty knife and and cut the connectors off of the board which would leave a clean pin I just had to pull from the holder. These boards that does not work on, I have been heating them on a hot plate and pulling the entire connector pins and all off of the board, I would then pull the pins ( photo 2) and then clip the pin off where the plating stops (photo 3).

As you can imagine it takes some time to do all of that and my fingers and thumb are wore out and I have several hundred connectors to do yet. My question is if I am going to process these in a sulfuric acid stripping cell to I really need to clip them off at the plating or can I just put the entire pin in and strip it that way ( photo 4) ?

Would the solder on the ends of the pins cause problems? This is new to me and I do not want to make my first attempt harder that it has to be. Any info would be appreciated....


Dave



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this are midgrade pins I love the pins you can get 4-5 grams of 24 k gold from 1kg of this pins but you must cut the unplated part

 

[mythen10]

me alway I cut every pins I love the pins

 

[mythen10]

you must be patient drink some cola and start cut to get full plated part of them and after use nitric acid

 

[coincard]

I like the pins also but boy are they a lot of work and hard on the fingers... These have a deep yellow dull color so i think that is heavy plating, at least I hope so..

 

[mythen10]

I like the pins also but boy are they a lot of work and hard on the fingers... These have a deep yellow dull color so i think that is heavy plating, at least I hope so..

impossible to be heavy plated all Siemens electronics are poor in precious metal content , Siemens stuff probably is the worst ewaste you can find , the gold in pins are 4-5grams per kilo if you cut off the unplated part

 

[mythen10]

I like the pins also but boy are they a lot of work and hard on the fingers... These have a deep yellow dull color so i think that is heavy plating, at least I hope so..

all Siemens boards are low grade boards , high grade boards you can find in HP devices

 

[mythen10]

I like the pins also but boy are they a lot of work and hard on the fingers... These have a deep yellow dull color so i think that is heavy plating, at least I hope so..

every time when I find some Siemens stuff I start cry I hate Siemens

 

[orvi]

me alway I cut every pins I love the pins

Quite a different opinion from my side - I have to say I do not prefer pins. Lots of waste from processing them Low gold content in comparison with overall metal content that need to be dissolved.
Relays, fingers, switches, CPUs, IC chips... These are my favourite types of material to process.

 

[coincard]

I have found quit a bit of gold plated chips, pins and things on Siemens boards, grated I have not processed them yet, but hope to soon...

 

[Ag and Au]

I have 2 kilograms of assorted cut pins from 1980's telecom boards that I plan to put in my AP bucket. I have two questions:

1) Should I seperate the magnetic pins from the non-magnetic pins prior to AP? Most pins are non-magnetic, but some are strongly magnetic (iron?) and some are mildly magnetic (Nickel?)

2) Will my ~ 3 gallons of AP digest the 2 Kg of base metal? Is there any data correlating base metal weight to AP volume?
Thank you

 

[BGDOCK]

every time when I find some Siemens stuff I start cry I hate Siemens

Do you work for Johnson Controls ?

 

[BGDOCK]

I recently purchased 125 Siemens industrial PLC boards, the kind they use to run automation equipment. The boards that had Cpus on them had 386 and 486 processors so they have been around for a while.

All of the boards had at least 2 and some had 3 or 4 IDE type connectors on the boards (see photo 1). On normal type boards I would use a steel putty knife and and cut the connectors off of the board which would leave a clean pin I just had to pull from the holder. These boards that does not work on, I have been heating them on a hot plate and pulling the entire connector pins and all off of the board, I would then pull the pins ( photo 2) and then clip the pin off where the plating stops (photo 3).

As you can imagine it takes some time to do all of that and my fingers and thumb are wore out and I have several hundred connectors to do yet. My question is if I am going to process these in a sulfuric acid stripping cell to I really need to clip them off at the plating or can I just put the entire pin in and strip it that way ( photo 4) ?

Would the solder on the ends of the pins cause problems? This is new to me and I do not want to make my first attempt harder that it has to be. Any info would be appreciated....

If you have all the pins out of the plastic the sulfuric cell is the best way imo.



I found out that prying a long flat screwdriver in between the rows of pins gets the plastic from the pins leaving them on the board. You can then wiggle them off until they break, without solder on the ends.
Put the connector in a vice and push the screwdriver in. Pry open each row separately, a couple of pins at a time.

But if the pins are still in the plastic and off the boards, you could go straight for AP.
I tossed a bunch of exactly those control cards connectors in AP and they came out clean after some rinsing. All the copper was eaten out. That plastic does not dissolve in AP.

Not sure if solder in AP is a big problem, some members toss whole boards in AP.
I have also done it once and haven't had any problems with that batch.

Martijn.

Bull nose pliers really cuts through plastic /metal and if you can get both jaws around it it pries away pretty easily

 

[Ag and Au]

I do not work for Johnson Controls

 

[BGDOCK]

I do not work for Johnson Controls

I was responding to mythen 10 crying when he sees Siemens cards , Johnson controls is another control company . Nice pile of pins . On the other hand good luck with the AP .
Use a bubbler , let sit for a while then decant and let the remaining pins oxidize for a couple of days then add fresh HCl. . Filter all AP ,

 

[FrugalRefiner]

I was responding to mythen 10 crying when he sees Siemens cards ,

mythen10 was banned late last year. If you look at his username, you'll see a line through it. Also, right under his username you'll see the word Banned.

Dave

 

[BShan]

Hi, I'm new, so please take my lack of experience into consideration when reading my response.

The original poster earlier in the thread mentioned going with a sulfuric cell instead. Do you have a way to test out a sulfuric cell to see if it would be suitable? I ran a small-scale test of some very low grade pins. It was meant to be a small-scale test, but I ended up processing over 1kg, through a <100mL cell. Having a multimeter inline, in Current reading mode, really helped visualize how strong or weak the reaction was going once the solution got cloudy and dark. Things I'm uncertain about in your case:
1. the inside surfaces of hollow items - I don't know how important it is for there to be a "line of sight" from the gold surface to the electrode. I wonder if only the outside surface will deplate.
2. The parts where the plating is not exposed to acid - I very much doubt that this plating will be removed.
3. chemical compatibility - I know copper is safe enough in Sulfuric acid, and I didn't have any problems with the nickel-plated copper with partial gold pins that I experimented with. But literature says that copper, and metals above it (more reactive) in the reactivity series are weak to sulfuric.

I think where "AP" comes into play, is if you have scrap which is mostly copper, since you can recover the copper salts that crash out, "recycle/refresh" the solution, and fairly cheaply be ready to add more pins to digest.

Hmm, so after typing that out, it seems like we have several good ways to deal with copper base metals. I'm not sure what the experienced consensus would be on ferrous base metal gold plated things.

Edited:
To change "air" to "acid" per Martijn. The devil's in the details, I should be more careful.

 

[BGDOCK]

mythen10 was banned late last year. If you look at his username, you'll see a line through it. Also, right under his username you'll see the word Banned.

Dave

I did see it after I posted but it was too late to edit . My bad )paying attention to details matters) .

 

[Martijn]

Hi, I'm new, so please take my lack of experience into consideration when reading my response.

The original poster earlier in the thread mentioned going with a sulfuric cell instead. Do you have a way to test out a sulfuric cell to see if it would be suitable? I ran a small-scale test of some very low grade pins. It was meant to be a small-scale test, but I ended up processing over 1kg, through a <100mL cell. Having a multimeter inline, in Current reading mode, really helped visualize how strong or weak the reaction was going once the solution got cloudy and dark. Things I'm uncertain about in your case:
1. the inside surfaces of hollow items - I don't know how important it is for there to be a "line of sight" from the gold surface to the electrode. I wonder if only the outside surface will deplate.
2. The parts where the plating is not exposed to air - I very much doubt that this plating will be removed.
3. chemical compatibility - I know copper is safe enough in Sulfuric acid, and I didn't have any problems with the nickel-plated copper with partial gold pins that I experimented with. But literature says that copper, and metals above it (more reactive) in the reactivity series are weak to sulfuric.

I think where "AP" comes into play, is if you have scrap which is mostly copper, since you can recover the copper salts that crash out, "recycle/refresh" the solution, and fairly cheaply be ready to add more pins to digest.

Hmm, so after typing that out, it seems like we have several good ways to deal with copper base metals. I'm not sure what the experienced consensus would be on ferrous base metal gold plated things.

1: current will go around and in between holes and gaps where there is gold exposed. cbare copper will not draw any current, so it 'searches for the path of least resistance = gold surfaces. No need for a straight path, I used closed copper mesh baskets (copper all around and the edges sticking above the acid) and had no problems stripping inside the basket, and inside hollow pins. the open front as shown in video's is not needed.
2: air? you means acid? parts that are tight together will stay plated. you need some room in between, the same can happen with a lot of flat pieces, bend them a bit so none will fit tight together.
3: Copper only dissolves in hot concentrated H2SO4, not in diluted acid and not in cold concentrated H2SO4. that's why we use 95% + concentration.
other metals also need some water to go in solution. they are not as soluble in concetrated acid.

Martijn.

 

[Ag and Au]

Hello, I will soon have ~3 kilograms of non-magnetic, assorted gold plated, cut pins and connectors from 1980's telecom boards that I plan to put in my 5 gallon AP bucket with a bubbler.

Is there any down side putting all 3 Kg of material in my 5 gallon bucket of AP at once? Or should I divide it into three x 1 Kg AP processes? Time is not a factor - I can leave it for months...

 

[Yggdrasil]

Hello, I will soon have ~3 kilograms of non-magnetic, assorted gold plated, cut pins and connectors from 1980's telecom boards that I plan to put in my 5 gallon AP bucket with a bubbler.

Is there any down side putting all 3 Kg of material in my 5 gallon bucket of AP at once? Or should I divide it into three x 1 Kg AP processes? Time is not a factor - I can leave it for months...

Since time is not important, smaller batches might be more controllable.
And you can have multiple batches at the same time.