# Gold Plated Pins



## snoman701 (Nov 28, 2017)

Here...the braggart is at it again.

I spent a couple hours shoveling hydroxide waste today, so that means I got some free XRF data on some of my scrap. 

1 lb of what I would call a medium sheen, thin, bent sheet construction molex style pin came in at 1.25% Au by weight. Crucible was brand new for this melt. 

1 lb of half coated ENIG pins that I would normally not waste my time picking up came in at 0.2% Au by weight. These were dirty and had on average a 1/4" of copper wire sticking out the back. Frankly, some of that gold likely came from the crucible from the first batch of pins that were melted. 

Analysis made by desktop thermo fisher energy dispersive XRF. Samples were pin samples from the above lots which were melted via induction heater. Pins were cut, rolled out & cleaned lightly with hand soap and pumice. Analysis performed by an operator that Lou considers an expert in the field and there was an offer to purchase based upon assay. 

Just some good data. I'll see if I can find some pictures to post later.


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## niks neims (Nov 28, 2017)

snoman701 said:


> 1 lb of half coated ENIG pins that I would normally not waste my time picking up came in at 0.2% Au by weight. These were dirty and had on average a 1/4" of copper wire sticking out the back.



wow, that is a lot!
i was under impression that eaven full coated pins from newer motherboards (>p4) are yielding no more than 1g/kg...

too bad


snoman701 said:


> some of that gold likely came from the crucible from the first batch



cool info, thanks man


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## anachronism (Nov 28, 2017)

Put some pics up but how do you know they were ENIG plating thickness?


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## snoman701 (Nov 28, 2017)

anachronism said:


> Put some pics up but how do you know they were ENIG plating thickness?



They just have a really transparent look, are overly reflective, and I can wipe through the gold layer with the rubber on my phone case. So I guess it may not be ENIG, but it's NOT quality plating. 

These are pins from airbag wiring harnesses. According to Yazaki, the only place gold plated conductors are used in automotove harnesses are airbag related. 

Pic attached.


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## niks neims (Nov 28, 2017)

mind sharing the pictures of the first kind of pins, also?


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## snoman701 (Nov 28, 2017)

Ok, so I lied. Actually, my memory just sucks right now. The gold was 1.4%

You can figure out which XRF results are which, and you can see that I clearly didn't remember how much I had either. Just shy of a pound and only about a half pound of the junky pins. I had enough to get a good melt, and a good sample. 

But the attached pic shows similar pins as well.


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## goldsilverpro (Nov 28, 2017)

At 1.41% (1.47 - .06) gold, that's $266/pound. No offense, but I don't believe it.


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## snoman701 (Nov 28, 2017)

goldsilverpro said:


> At 1.41% (1.47 - .05) gold, that's $266/pound. No offense, but I don't believe it.



NONE TAKEN! 

I was shocked.

Even the guy that melted them said that if it wasn't a fresh crucible, he would have attributed it to picking up gold from a previous melt.


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## goldsilverpro (Nov 28, 2017)

With a good sample, fire assay never leaves a doubt. With XRF, there is always a doubt for something like this, in my opinion.


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## snoman701 (Nov 28, 2017)

I don't doubt whether the reading is correct. It is. There is no doubt in my mind that the pin sample contains 1.4% Au.

The doubt would be whether the pin sample was a representative sample.

That doubt would still exist if it were a fire assay.

Or are you just talking about taking a few pins and trying to oxidize off some of the copper in the fusion? (Is fusion the right word?)



Sent from my iPhone using Tapatalk


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## goldsilverpro (Nov 29, 2017)

You now know the Au content on the surface of the pin sample.


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## Lou (Nov 29, 2017)

I believe that the analyst he uses preference is to roll out the pintube sample as taken from the induction furnace and polish the surface before using XRF. If the pin tube was not polished after rolling to size for the aperture coverage, then gold transfer from the rolls is possible. Only thing impacting the result would be phase segregation or tungsten, which often shows up as Au on Energy Dispersive spectrophotometers. 


Rather than fire assay, a good digestion of the pin tube's resulting product in nitro-sulfuric acid would yield fine gold.


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## snoman701 (Nov 29, 2017)

The rolled pin tube was polished, and there was good aperture coverage. I don't know where tungsten would come from unless there was contamination on the new crucible from Morgan.


Sent from my iPhone using Tapatalk


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## snoman701 (Nov 29, 2017)

I stopped to visit today and discuss the controversy. 

From his experience:

If he has just melted karat scrap, pulled a pin and rolled it out...then immediately melted fine silver, and pulled a pin and rolled it out, without cleaning the rolls and without polishing the silver, he will often see a 1/4 of a percent of gold via contamination from the rollers, but rarely is it more than that. 

He again reiterated that he would have attributed some of the gold to contamination from the crucible, if it wasn't a brand new crucible. 

He did say that he sees a good amount of this type of scrap, and that these are quite high in comparison to what he normally sees from melting pins. I pointed out my observation that he did offer to buy based upon the assay, and his response was quite emphatic that it would be in his best interest to have the number come in lower!

I will say that his initial subjective appraisal of the spectral analysis, without referring to the actual counts, just the spectrum as it shows up on the screen...was that it would not come in anywhere near 1.4%. 

With all of that, he is quite insistent that I return the ingot to him. We will grind the surface of the ingot to hopefully avoid any surface stratification, and run an xrf off the bar itself. I imagine that if he is still annoyed, he'll end any controversy by remelting, pulling another pin, then running it through the wavelength dispersive XRF. 

I don't have time to digest the pin in acid, or I would.


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## niks neims (Nov 29, 2017)

ok, so the one kind of pins came from automobile air-bag harnesses, any idea where did the other kind of pins came from?


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## snoman701 (Nov 29, 2017)

Lou said:


> Only thing impacting the result would be phase segregation or tungsten, which often shows up as Au on Energy Dispersive spectrophotometers.



I think that is because the tungsten L beta 1 excitation energy is 9.672 KeV, which is very close to the gold L alpha 1 spectral line of 9.713 KeV. (please correct me if wrong)
On further Edit: The niobium identified in both samples shown above is possibly/likely erroneous as well? In this case their spectral lines occur at 2.166 KeV for the Niobium L alpha and 2.120 KeV for the Gold M alpha. 

But what would cause excitation of gold, without any excitation of tungsten at the K spectral lines? I feel like if it were tungsten, there would still be some trace of tungsten represented within the sample. 

On Edit: Nevermind, Maximum KeV is 50, the K spectral lines occur at 59 & 68 KeV for W and Au, respectively. Even with, shouldn't you see both L alpha and L beta lines for any present sample at minor and trace concentrations? 



niks neims said:


> ok, so the one kind of pins came from automobile air-bag harnesses, any idea where did the other kind of pins came from?



Not a clue...sorry.


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## snoman701 (Dec 1, 2017)

Pins were analyzed again today by grinding a good depth in to the bar.

Analysis showed 1.49% Au



snoman701 said:


> I think that is because the tungsten L beta 1 excitation energy is 9.672 KeV, which is very close to the gold L alpha 1 spectral line of 9.713 KeV. (please correct me if wrong)



This is correct. Especially in hand held units, tungsten and gold can be misidentified as well as iridium/platinum/gold. 



snoman701 said:


> On further Edit: The niobium identified in both samples shown above is possibly/likely erroneous as well? In this case their spectral lines occur at 2.166 KeV for the Niobium L alpha and 2.120 KeV for the Gold M alpha.



This is incorrect. The niobium is likely a second order interference that occurs at Niobium's K line..


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## anachronism (Dec 1, 2017)

goldsilverpro said:


> At 1.41% (1.47 - .05) gold, that's $266/pound. No offense, but I don't believe it.



I've been wrong before and I'll be wrong again I'm sure, however I'm with Chris on this. I've processed some pretty mean pins in my time the best being from some Russian telecoms (with Nickvc) where the gold was coming off in sheets. These were still not 14g per Kg. These pins do not look anything like the hue I would expect from high depth plating in fact it looks like the cheaper end of the scale. 

As I said before I could be wrong however my head is telling me that your result isn't practically correct.


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## snoman701 (Dec 1, 2017)

At this point, I honestly don't care if there's 0.1 g or 4 grams in the bar, I don't have a steady supply of them, I don't know the source...so it's sort of a fools errand to continue to debate it.

The only reason I wanted to perform the analysis in the first place was to see a range of values from what I felt were good quality to what I felt were pretty low quality. 

The only reason I shared is because I thought people would appreciate seeing an assay performed by an expert analyst. Not the case I guess.


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## FrugalRefiner (Dec 1, 2017)

Snoman, thanks for sharing your experience. I thought the details of how the samples were prepared were particularly interesting. I will probably never process the exact same material you did, so the yield numbers aren't as significant to me as the process, but I'm only speaking for myself.

Dave


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## silversaddle1 (Dec 1, 2017)

As you guys know, I've pulled millions of pins in the 17 years that I have been doing it. Some say it's a waste of time but I enjoy doing it in my little spare time. Out in the shop alone, put some Pink Floyd on and just relax and enjoy myself. Utopia! Back onto track here. I've seen these types of pins before. And if I recall correctly, they come out of the old "Buss & Tagg" type connectors. I'm not 100% sure but they sure look like the male pins. If so, we are looking at 70's vintage, enterprise type pins. If I'm correct, I had 30 pounds of them at one time.


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## snoman701 (Dec 1, 2017)

FrugalRefiner said:


> Snoman, thanks for sharing your experience. I thought the details of how the samples were prepared were particularly interesting. I will probably never process the exact same material you did, so the yield numbers aren't as significant to me as the process, but I'm only speaking for myself.
> 
> Dave



I think I'm going to do an induction melter build, so you'll get more of the process on that side. I've spent some time studying them, and was initially looking for an old one, but it's just not worth it. From a control side, there's really not much to them. It's just a PWM, phase lock loop on the feedback controlling a giant IGBT. The stupid snubber capacitors will be the expensive part. 

This gentleman takes an interesting pin sample as well. He uses a piece of quartz tubing, submerges the tip in the same manor as a regular vacuum pin, then very quickly pulls a sample using a turkey baster. It's the exact same process, just a different spin. Plus, if you are lucky and the pin slides out easy, you can use the same piece of quartz tube quite a few times. 

I asked him for a couple pieces of tubing and got the warning, "I make this look really easy but there is a bit of coordination to it". And after he described it, it's clear that his likely hundreds of thousands of melts over the last 30 years has taught him the muscle memory to make it appear really really easy. 

Then the XRF is another amazement to me in and of itself. The more I learn, the more I love it. I spent 45 minutes today talking to him about errors, analysis of results, the differences between machines and their limitations. In time, as I gain a greater understanding of it, I'm going to write up a review of XRF and analysis of precious metals, give it to him to proof, then post it. Absolutely amazing tool. He's been using XRF, in one form or another, since 1982.


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## goldsilverpro (Dec 1, 2017)

A guy I worked for taught me the turkey baster, glass tubing, thing 20 years ago. Worked great. In fact, I've discussed it several times on the forum.

No matter what, the results you got are unreliable. To me, if you can't hold the resulting pure gold in your hand, the result is questionable. Any digital result is potential garbage.


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## snoman701 (Dec 1, 2017)

goldsilverpro said:


> A guy I worked for taught me the turkey baster, glass tubing, thing 20 years ago. Worked great. In fact, I've discussed it several times on the forum.
> 
> No matter what, the results you got are unreliable. To me, if you can't hold the resulting pure gold in your hand, the result is questionable. Any digital result is potential garbage.



Yes, the results are always potentially unreliable...especially so without a skilled analyst that understands the limitations of his instrument.

And yes, gravimetric methods to determine gold purity still remain to be the gold standard, or at least the standard of the American Society for Testing and Materials.


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## g_axelsson (Dec 1, 2017)

Jumping into the debate here...

The pins doesn't look to be solid to me. If it is made from a wrapped sheet then there isn't a lot of base metal there and both sides that is plated. That in it self would increase the yield in percent compared to most pins that are massive.

I have no reason to doubt the numbers Snoman presents. There will always be the one anomalous sample that if it is only one type of pins the batch can be way off compared to mixed pins.

I once scrapped an old IBM system 3 machine. The connectors were nothing like I've ever seen before and the foils never swirled around after the base metals were dissolved, it just sank straight to the bottom. That machine gave me a 10 gram button.
Since that day I have kept looking for that kind of connector and now and then I find them too, but I have never managed to duplicate the yield from the first batch, it's always been normal gold plate on every connector I found since then.

I actually found the male pins that I harvested from that IBM back plane, I only processed the female connectors back at the time and the box with the male pins resurfaced two weeks ago. I'm looking forward to process these pins now. Half of the pins are gold plated while half looks like stainless steel but I suspect and hopes for some sort of PGM plating.

I also have pins from an Olivetti "calculator" from mid 1960:es that I'm also going to process. Thin gold plated steel wire... never run into that connector again either.

Göran


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## snoman701 (Dec 1, 2017)

Goran...are you talking about the ones with the little square gold pads on them when you reference the system 3 pins?


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## g_axelsson (Dec 2, 2017)

snoman701 said:


> Goran...are you talking about the ones with the little square gold pads on them when you reference the system 3 pins?


Yes, that's the ones, where the gold plated pad is spot welded to the end of a bent brass piece.
One time they were made from thick gold but since that it's been standard gold plate every time I've checked.

Göran


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## goldsilverpro (Dec 2, 2017)

Thinking about this further. They appear to be unused and could be rejects from a manufacturing facility. If so, I guess they could be rejected due to gold overplating, although I've never seen that happen before unless it caused dimensional or stress problems. 

Even in the most advanced production setups, there is still some "art" in any application of electroplating. The plating bath you will use tomorrow is never, ever identical to the same bath you used today.


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## snoman701 (Dec 2, 2017)

My goal here was simply to establish approximate values of pins for purchasing knowledge. I grabbed what I figured where the highest I had, and the lowest I had. If the assay is correct, clearly I succeeded on one side. Unfortunately, the data is pretty useless, as I'll probably never find pins like this again. After talking to a couple of people privately, it's clear that this number is not only high, but ridiculously high compared to even the best pins. 

With that, there's a couple things going on.

First, the pins I showed were not the ones that I were actually melted. From memory, they are identical, but the stress from Dad really killed my memory, so my memory is shot these days. So the value of sheen in this case is very unreliable. 

Second is exactly what you said. I get some prototype material. The quantity I got was perfect to do enough testing to determine applicability, but not nearly enough to do a production study. When production pins used to come in from the wiring harness companies, they are on reels...and they usually come in with all of the tooling to crimp them. Those haven't come in a couple of years unfortunately. I'd still say that 98% of that was nickel plated only though.


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## nickvc (Dec 3, 2017)

The one thought I had was if the pins were very light but had been plated to a military spec or above the results could make some sense, the best e scrap material I ever ran was yielding around 90 grams a kilo, it was a rare find but it happened several times with the exact same material.


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## Claudie (Aug 13, 2018)

> the best e scrap material I ever ran was yielding around 90 grams a kilo



What was the material?


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## nickvc (Aug 13, 2018)

It came from some military application I believe, never had anything else like it.


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## goldsilverpro (Aug 13, 2018)

The highest value pins I've seen were from WWII and they ran 1 tr.oz./pound. The highest fingers I've had ran about 7g/pound. A place I worked ran about 1000# of small, gold-plated, Kovar IC package lids that were new and had a Au/Sn preform mounted on them. They ran 1 oz/pound


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## philddreamer (Aug 13, 2018)

I've processed a couple hundred pounds of different types of pins. The highest yield per pound were the ones I toll refined for a fellow member from Baltimore back in 2013,
http://goldrefiningforum.com/~goldrefi/phpBB3/viewtopic.php?f=84&t=17438&p=176534&hilit=Bryan#p176534
almost 1 T oz per pound!
I wish I could come across some more of them!  

Take care!
Phil


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## Claudie (Aug 13, 2018)

Does anyone here know the yield of the small Gold plated balls that are found in the (usually red or blue) switches from circuit boards? 
I know it takes a bunch of switches to acquire the quantity of balls needed to determine yield.


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## kernels (Aug 23, 2018)

Claudie said:


> Does anyone here know the yield of the small Gold plated balls that are found in the (usually red or blue) switches from circuit boards?
> I know it takes a bunch of switches to acquire the quantity of balls needed to determine yield.



From this video https://youtu.be/pi9VOfsGbqg it looks like the balls hold together reasonably well, so the plating thickness must be decent. No idea what the overall yield would be though.


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## Claudie (Aug 23, 2018)

Thank you kernels. 
I have seen many of this guy's videos but I missed that one. I have a jar with several of these balls mixed in with other small, fully plated pieces. I also have several switches that I haven't taken apart yet. Maybe I can get enough of them together to estimate an average yield.


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## glorycloud (Aug 23, 2018)

This is a post that I did from 2009 inquiring about the gold balls in the red switches. 8) 

http://goldrefiningforum.com/~goldrefi/phpBB3/viewtopic.php?t=4596


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