# Gold Pin Refining - Solid Gold? Unexpexted Results. Help?



## Crank (Aug 28, 2022)

All,
I should first say thank you to the members here. There really is some great info here for new hobbyist like myself.
I recently started processing some scrap connectors that have gold pins. To date, I've processed a few different materials all in the hopes of having a lot of foils ready to go. That way I can do batches of aqua regia all at the same time.
I've stripped some gold plated shields as well a handful of PCBs. They both had one thing in common- when placed in AP, there is a near immediate reaction.
Yesterday, I did a test by putting 20 or so pins in an AP solution. It was odd because nothing happened. I told myself to be patient and check it again 24 hrs later to see if there was a change. I checked the pins again this morning- again, no reaction at all. I've left those pins still in AP and will give them a week and will check once again.
Given what I found, I figured I would try melting some pins in a spare small crucible I bought and haven't used used. I took about 20 or so pins (shame on me for not documenting a measuring!) and I stated to apply some heat with a MAP torch. It took a bit, but the pins started to combine. Eventually, I had a red hot BB moving around in the crucible.
I dropped it into some water and found it came out more of a copper color than gold, so I put it back in the crucible and heated it again until it was a BB. I added a little flux and it seems like it separated impurities. I did this whole process 2 more times to try and see if I could get a more pure gold colored BB. It weighs .3g
I drenched it again and washed it with water. I decided to drop the nugget into some AP to see if anything happened. Again, nothing.
Now I'm baffled. I've attached a picture of what the pins look like next to the melted metal. It still looks a little dirty, but is it possible this is a nugget of gold?
I've not bought sulfuric yet because of what I noted below about wanting to have a lot of processed foils ready. I know that I could see if this is gold by trying to dissolve it into a solution. I also don't have what I need to do a stannous test.
I'd appreciate opinions


----------



## efka (Aug 28, 2022)

I guess the PCBs had solder on them? The tin in the solder reacts strongly with AP/HCl, copper on the other hand reacts slowly. Another possibility is that your AP went bad from the PCB stripping. Only CuCl2 is reusable over and over, if you have a mix of metals in your AP solution, it can stop working


----------



## Yggdrasil (Aug 28, 2022)

Crank said:


> All,
> I should first say thank you to the members here. There really is some great info here for new hobbyist like myself.
> I recently started processing some scrap connectors that have gold pins. To date, I've processed a few different materials all in the hopes of having a lot of foils ready to go. That way I can do batches of aqua regia all at the same time.
> I've stripped some gold plated shields as well a handful of PCBs. They both had one thing in common- when placed in AP, there is a near immediate reaction.
> ...


The bead looks like copper.
Are you bubbling air through your AP?
Have you refreshed it with some HCl?


----------



## Crank (Aug 28, 2022)

Yggdrasil said:


> The bead looks like copper.
> Are you bubbling air through your AP?
> Have you refreshed it with some HCl?


The AP hasn't been refreshed with HCL. I did add some hydrogen peroxide before i left it overnight, however.
I'll try a bubbler and give the pins a week to see if there is any noticeable reaction


----------



## Crank (Aug 28, 2022)

Here is another picture. It looks more gold colored here.


----------



## butcher (Aug 28, 2022)

I like to make nitric acid with thick gold-plated pins in a recovery process of gold...

You may need to cut thick gold plated pins into small pieces in order to better expose the copper core to the cupric chloride leach, the thick gold plating can make it hard for the leach to reach the copper.


----------



## Alondro (Aug 28, 2022)

butcher said:


> I like to make nitric acid with thick gold-plated pins in a recovery process of gold...
> 
> You may need to cut thick gold plated pins into small pieces in order to better expose the copper core to the cupric chloride leach, the thick gold plating can make it hard for the leach to reach the copper.


Need to be sure the pins are copper core and not brass. Brass ones will have tin, and lead to metastannic acid.

I use the CuCL2-HCl method. Just need to swirl it now and then, and in about a week, most of the base metals are dissolved, and the only solids are gold foils and Cu(I)Cl crystals, which can be easily dissolved with fresh HCl.


----------



## Alondro (Aug 28, 2022)

Crank said:


> Here is another picture. It looks more gold colored here.


You probably have a copper-gold alloy now which HCl-peroxide won't attack easily. Probably time for AR or HCl-bleach to dissolve the whole lump.


----------



## FrugalRefiner (Aug 28, 2022)

Alondro said:


> Need to be sure the pins are copper core and not brass. Brass ones will have tin, and lead to metastannic acid.


Brass is an alloy of primarily copper and zinc. Bronze is an alloy of primarily copper and tin.

Dave


----------



## BlackLabel (Aug 29, 2022)

I also think, the pins were high quality/thick plated (medical, military or very old).
The AP was unable to penetrate the plating.
Cutting the pins in three pieces would have opened the brass core for the AP.
Now you might have a gold-copper alloy of about 12k and the AP can't attack it.

You could try some kind of "poor mans inquartation":
Remelt your button with the same amount of copper, pour it into water in order to get pieces with larger surface and try it again with AP.
I guess, you will end up with something between 0.15 and 0.2 grams of gold.

Because of the small amount, you have to be very careful on decanting and filtering.
Keep all waste solutions in a stock pot.

Good luck!


----------



## Crank (Aug 29, 2022)

BlackLabel said:


> I also think, the pins were high quality/thick plated (medical, military or very old).
> The AP was unable to penetrate the plating.
> Cutting the pins in three pieces would have opened the brass core for the AP.
> Now you might have a gold-copper alloy of about 12k and the AP can't attack it.
> ...


I think I may just chalk up that button to a learning experience. I don't want to waste the time on trying to make something out of it when I still have other raw material to refine.
You are correct - the pins are all stripped down from scrapped mil components. 
This evening I am trying to remove all of the pins from the epoxy thats holding them. I would like to dissolve them in AR instead of AP but I want to keep the epoxy away from that solution. I ordered some sulfuric today.
In the meantime, I am also still running the test noted above in one of my earlier posts. I have a small batch of pins still in epoxy that have been processing for 24 hours in fresh AP with a bubbler. I'm still seeing no noticeable reaction where gold is separating. I may throw in a couple pins that I've snipped into pieces.


----------



## FrugalRefiner (Aug 29, 2022)

Crank said:


> I think I may just chalk up that button to a learning experience. I don't want to waste the time on trying to make something out of it when I still have other raw material to refine.


Throw it in your stockpot. As you put your waste acids in, they will consume the base metals, and in the end, you'll recover the gold without any additional effort or expense.

Dave


----------



## Crank (Sep 14, 2022)

I wanted to follow up on this to report my findings. I've left the pins in AP for about a week now with no observable change. I do see that some of the pins now feel a little 'soft', but I am not seeing a discoloration of the AP which would indicate that there is a high level of copper present.
Rather than just hitting some pins with a torch, I'm considering putting some pins right onto AR. Would anyone advise against this?
On page 41 and 42 of Hoke, she speaks to a treatment using only Sulfuric. Should I do this first?


----------



## orvi (Sep 14, 2022)

Crank said:


> I wanted to follow up on this to report my findings. I've left the pins in AP for about a week now with no observable change. I do see that some of the pins now feel a little 'soft', but I am not seeing a discoloration of the AP which would indicate that there is a high level of copper present.
> Rather than just hitting some pins with a torch, I'm considering putting some pins right onto AR. Would anyone advise against this?
> On page 41 and 42 of Hoke, she speaks to a treatment using only Sulfuric. Should I do this first?


I never had the luxury of using nitric to eat BM from pins and either time to run AP bucket. So to this day, I only use AR for digestion of any metal based gold materials (that is suitable). You need to get familiar with very dark coloured solutions, which are hard to see through. I regularly do pins in AR... no problem. It isn´t the nicest method, gold drop is many times very light and require whole day to settle properly, and of course need second refine. But recovery rate is practically the same as with other methods. 
Take a test batch and dissolve it in AR, few pcs. Ammount of gold you can also judge from the colour of the solution.
And don´t be fooled by golden colour of the alloy - either brass or bronze can be that coloured. And also hard silver alloys (AgCusomething).


----------



## orvi (Sep 14, 2022)

Crank said:


> All,
> I should first say thank you to the members here. There really is some great info here for new hobbyist like myself.
> I recently started processing some scrap connectors that have gold pins. To date, I've processed a few different materials all in the hopes of having a lot of foils ready to go. That way I can do batches of aqua regia all at the same time.
> I've stripped some gold plated shields as well a handful of PCBs. They both had one thing in common- when placed in AP, there is a near immediate reaction.
> ...


Stannous test can get you rough idea of how much gold is in the sample judging by the colour. I would advise to dissolve that melted blob in AR and test with stannous. If they run over 1% Au (10g/kg), it would be clearly visible and stannous will be plain black colour. Very deep. With signs of individual particles separating from the colloid.
If it is serious % AuCu alloy, you will clearly see the colour of the AR solution - much more yellowish/orange-y tinge. Stannous would be plain black, opaque. Altough, I never encountered AuCu alloy in electronics (also MIL, old Soviet, any), but I stumbled across Au75Ag, Au95Ni and Au70Ag25Ni5 several times.
Very easy to spot the difference with plating as gold has notorious gold colour (  ) but these alloys are pale in colour, many times with greenish tinge, and some does not resemble gold at all (Au70Ag25Ni5). Very rare to find them, almost exclusively found as material of contact points in high-end relays, switches, sliders in potentiometers and rotary switches.


----------



## Findm-Keepm (Sep 15, 2022)

Another possibility: Au-plated Beryllium Copper pins. They are even more common these days, especially in wire-to-board applications where flex may be an issue. Also, most spring "fingers" in card-edge connectors are likely plated BeCu.

I had to go the H2SO4 cell to strip the gold from a bunch of (known) Gold-plated BeCu pins.


----------



## Alondro (Sep 15, 2022)

Findm-Keepm said:


> Another possibility: Au-plated Beryllium Copper pins. They are even more common these days, especially in wire-to-board applications where flex may be an issue. Also, most spring "fingers" in card-edge connectors are likely plated BeCu.
> 
> I had to go the H2SO4 cell to strip the gold from a bunch of (known) Gold-plated BeCu pins.


Gotta be REAL careful with beryllium salts. They're extremely toxic, similar in toxicity to arsenic! 4mg is enough to be considered an immediate health danger!


----------



## orvi (Sep 15, 2022)

Findm-Keepm said:


> Another possibility: Au-plated Beryllium Copper pins. They are even more common these days, especially in wire-to-board applications where flex may be an issue. Also, most spring "fingers" in card-edge connectors are likely plated BeCu.
> 
> I had to go the H2SO4 cell to strip the gold from a bunch of (known) Gold-plated BeCu pins.


With typical pins, there are practically four major possibilities of what they can be made of:
Brass (CuZn)
Bronze (CuSn)
Magnetic alloys (kovar etc.)
Beryllium copper (CuBe)
Other alloys are rare, saying from my personal experience. Counting hard silver (AgCu) or other strange copper alloys.

Convenient is to zapp them with XRF, altough I know that majority of people does not have access to one. If it is brass or bronze, you will clearly see by presence of either zinc or tin. Kovar is easily distinguished as it is slightly magnetic or magnetic. And if the XRF is showing only copper - no Sn or Zn - you can be quite sure it is beryllium copper, since XRF does not see beryllium.
And yeah, you need to cut off the tinned parts with solder - they will mess up whole "assay". XRF will conveniently see through gold plating and show also the material of the pin, but ratios may be skewed due to gold "shielding". You will regularly see nickel, as it is used as underplating on copper based materials.

By experience with certain type of machine, you can guesstimate the gold content of the pins by % of gold shown - in my case with Olympus Vanta, I empirically learned that to 10g/kg Au it goes with order of 3. 3% Au = 1g/kg. VERY VERY ROUGHLY. You also need to account for the material thickness. I just use it as convenient and very quick tool to distinguish good and poor pins, nothing else. Melting "assay" gives you +-5% result when button is properly melted, sanded and zapped with XRF.

Don´t forget to account for melting loss - thus weighing raw pins and also melted flattened button. You need just something like 1,5g of pins to perform this conveniently. Melting in quartz dish with oxy/propane is done under 3-4 minutes, additional ca 3 mins for cleaning, flattening, weighing and sanding. 2 minutes for zapping with XRF and doing the math. If you are well setup, you can do this pseudo-assay in less than 10 minutes whole.
When I hadn´t regular access, I done like 5-10 these pseudo-assays in advance, then paid few bucks for the machine time in one shop and during 10 minutes zapped all buttons and had results in my hand


----------



## orvi (Sep 15, 2022)

Alondro said:


> Gotta be REAL careful with beryllium salts. They're extremely toxic, similar in toxicity to arsenic! 4mg is enough to be considered an immediate health danger!


I would say worse, because arsenic is somewhat excreted from body, altough it is very cumulative. Be is very small and has insane charge to radius ratio. It binds everywhere where magnesium does, and bond is permanent. At least this is what I said in textbooks. Due to very small ionic radius, it penetrate skin and membranes like nothing


----------



## Daniel0007a (Sep 16, 2022)

A video on strips if they are gold plated may contain 1-2 percent gold. This is from strips. Interesting but you will prob not get a lot of gold. Streeps took 4760 g of gold pins and got 23 g gold out of it.


----------



## orvi (Sep 16, 2022)

Daniel0007a said:


> A video on strips if they are gold plated may contain 1-2 percent gold. This is from strips. Interesting but you will prob not get a lot of gold. Streeps took 4760 g of gold pins and got 23 g gold out of it.


Above 4-5g/kg pins I consider relatively good recovery worth chasing, even with AR (if they are soldered and you cannot get full recovery with cyanide or sulfuric cell). Altough I much more like to process higher grade pins, like more than 10g/kg - less waste per ammount of gold recovered. And top scrap for me are ceramic ICs and CPUs. Little metal = little waste, purer crude gold solutions


----------



## Daniel0007a (Sep 16, 2022)

Yes CPU could be heated in a Propane stove or a Kilm to drive off plastic and CO2 giving you Pure gold. Or you could break the CPU open and remove the gold from the CPU. However many CPU will have Only 100-300 mg of gold inside. An older CPU from the 1990 may be better in recovering gold.


----------



## orvi (Sep 16, 2022)

Daniel0007a said:


> Yes CPU could be heated in a Propane stove or a Kilm to drive off plastic and CO2 giving you Pure gold. Or you could break the CPU open and remove the gold from the CPU. However many CPU will have Only 100-300 mg of gold inside. An older CPU from the 1990 may be better in recovering gold.


There is not much in modern fiber CPUs, so processing on small 1kg scale isn´t very appealing to me. But if you are doing stuff like 386/486/MMX/etc. then it could be very interesting since reasons I enumerate above.
Not very much CPUs have more than 300mg gold per unit. Most frequent one, which is Pentium, has average 2g/kg (no gold lid or bottom). But when you imagine how much metal it contain, it is very economical to process CPUs rather than pins in AR.


----------



## Daniel0007a (Sep 16, 2022)

Since a cpu gold woud be very expensive for a 386 or 486 Processor it may be worth collecting it or a gold bar and extracting it for gold purposes. Poorman chem took an Canadian coin made of Pd (Palladium) and made Pd black and Palladium ammonia chloride Pd(NH4)2Cl2.


----------



## Daniel0007a (Sep 16, 2022)

I mean 2 g of gold per cpu if you can get a lot of them it def worth it.


----------



## orvi (Sep 16, 2022)

Daniel0007a said:


> Since a cpu gold woud be very expensive for a 386 or 486 Processor it may be worth collecting it or a gold bar and extracting it for gold purposes. Poorman chem took an Canadian coin made of Pd (Palladium) and made Pd black and Palladium ammonia chloride Pd(NH4)2Cl2.


Depends. Time to time, I purchase quite a bit of CPUs despite they has collectors value. But I do not have time to sell it piece by piece on eBay or various other marketplaces. So I process them instead. I am oriented to make profit from it, so I do not know what "gold purposes" are, but my purpose of gold is to sell it 


Daniel0007a said:


> I mean 2 g of gold per cpu if you can get a lot of them it def worth it.


Never seen a CPU that gave 2g per unit. I wrote 2g per kg of Pentiums.


----------



## Daniel0007a (Sep 16, 2022)

If the pins have lead in them you can add to AR a few drops of conc 98 percent Sulfuric acid to make Lead Sulfate. It will form with Sulfuric acid and AR a soluble lead salt. You can remove lead from the gold this way. 

If not hot the Aqua regas and sulfuric acid will dissolve the lead leaving gold alone.


----------



## Daniel0007a (Sep 16, 2022)

Useful to purify gold and copper.


----------



## jphayesjr (Sep 17, 2022)

Be is both acutely toxic and carcinogenic/teratogenic. Don't get salts or solutions on your skin, eyes, mouth. Don't inhale beryllium containing powders. And yes, once bonded where magnesium interfaces in body, it is in place permanently. Modern medicine has not found a way to chelate it and remove from the human body. A friend of mine who built bespoken custom ultralight bicycle frames with Sandvik Be-Al tubing learned the hard way many moons ago. Irreversible pulmonary edema is a hideous way to check-out of this life. Retail prices for 99.999% pure Be chunks run from USD $5 to $8 per gram. Demand from aerospace and telecom and digital equipment industries are growing rapidly. It is feasible to recycle it, just challenging to do it safely. DO NOT ATTMPT TO MELT unless you have a hood with neutral gas capability, and capability to clean up and contain the dust. If you dissolve BE-Cu alloy chemically, you'll eventually precipitate it as a salt-- if you accumulate it, keep it in a wet condition, covered by several centimeters of water in a closed securely sealed vessel. Safely discard other filtrates and liquids. Unless you're mad as a hatter, why would you want to turn your place into a superfund site?
Here's a YouTube link from the UK you may find helpful from someone who avoided becoming a berylliosis victim...  NB PEr EU criteria, beryllium is a Class 1 carcinogen.

I have personal experience with berylium based minerals myself, having worked a lot with various types of beryls for gemological purposes...I do not cut it in my studio anymore. When I find it during prospecting jaunts, I grade it, and accumulate or immediately sell either as ore or as cabbing/faceting rough. My friend's demise was a wake-up call for us all.


----------



## jphayesjr (Sep 17, 2022)

Alondro said:


> Gotta be REAL careful with beryllium salts. They're extremely toxic, similar in toxicity to arsenic! 4mg is enough to be considered an immediate health danger!


Like, if you are working with beryllium or its' alloys, it's a good idea to wear a faceplate respirator with two stage filtering (activated charcoal and sintered wafers) that traps particles down to 0.5 microns...Binks Corp. used to make them. I think someone else bought the brand, so check NIOSH. Someone out there is bound to say I'm being picky and sissyish. Read my other reply above. Even a few mg of beryllium powder circulating in the air of your lab is a clear and present hazard. Even clipping beryllium wire causes shedding of burrs. It is insidious.


----------



## Alondro (Sep 18, 2022)

orvi said:


> Depends. Time to time, I purchase quite a bit of CPUs despite they has collectors value. But I do not have time to sell it piece by piece on eBay or various other marketplaces. So I process them instead. I am oriented to make profit from it, so I do not know what "gold purposes" are, but my purpose of gold is to sell it
> 
> Never seen a CPU that gave 2g per unit. I wrote 2g per kg of Pentiums.


There's one type of ceramic Pentium Pro that has over 1 gram of gold per processor. But those are not very common.


----------



## FrugalRefiner (Sep 18, 2022)

Alondro said:


> There's one type of ceramic Pentium Pro that has over 1 gram of gold per processor. But those are not very common.


I have read that ever since I joined this forum, but I've never seen a member say they actually had that result.

Are you saying you've actually refined them, or is that information from one of the infamous lists?

Dave


----------



## Alondro (Sep 19, 2022)

FrugalRefiner said:


> I have read that ever since I joined this forum, but I've never seen a member say they actually had that result.
> 
> Are you saying you've actually refined them, or is that information from one of the infamous lists?
> 
> Dave


I haven't found one to refine myself. I only know a guy who did and confirmed it was about a gram. Even so, I wouldn't pay the absurdly high prices people usually want for them. What's the point of paying virtually the amount of the gold value inside them? If I found them cheap, well yeah I'd grab them! 

For a hobbyist who's just doing it for fun, that's fine. But to make money, they're a fool's errand. There aren't that many of them, and they're always priced too high.

Basically, if you buy a big lot of stuff for a reasonable price, and find a few of the Holy Grail of CPUs mixed in, it makes your day. Basically like finding a quarter in a jar you thought was just full of pennies.


----------



## jphayesjr (Sep 19, 2022)

jphayesjr said:


> Be is both acutely toxic and carcinogenic/teratogenic. Don't get salts or solutions on your skin, eyes, mouth. Don't inhale beryllium containing powders. And yes, once bonded where magnesium interfaces in body, it is in place permanently. Modern medicine has not found a way to chelate it and remove from the human body. A friend of mine who built bespoken custom ultralight bicycle frames with Sandvik Be-Al tubing learned the hard way many moons ago. Irreversible pulmonary edema is a hideous way to check-out of this life. Retail prices for 99.999% pure Be chunks run from USD $5 to $8 per gram. Demand from aerospace and telecom and digital equipment industries are growing rapidly. It is feasible to recycle it, just challenging to do it safely. DO NOT ATTMPT TO MELT unless you have a hood with neutral gas capability, and capability to clean up and contain the dust. If you dissolve BE-Cu alloy chemically, you'll eventually precipitate it as a salt-- if you accumulate it, keep it in a wet condition, covered by several centimeters of water in a closed securely sealed vessel. Safely discard other filtrates and liquids. Unless you're mad as a hatter, why would you want to turn your place into a superfund site?
> Here's a YouTube link from the UK you may find helpful from someone who avoided becoming a berylliosis victim...  NB PEr EU criteria, beryllium is a Class 1 carcinogen.
> 
> I have personal experience with berylium based minerals myself, having worked a lot with various types of beryls for gemological purposes...I do not cut it in my studio anymore. When I find it during prospecting jaunts, I grade it, and accumulate or immediately sell either as ore or as cabbing/faceting rough. My friend's demise was a wake-up call for us all.



If members are looking for a reasonable and competent source for PPE, may I call to your attention https://www.galeton.com ? I do not work for them, nor receive any benefit. They have excellent items and helpful sales and deals.


----------



## Soar2c (Sep 20, 2022)

FrugalRefiner said:


> I have read that ever since I joined this forum, but I've never seen a member say they actually had that result.
> 
> Are you saying you've actually refined them, or is that information from one of the infamous lists?
> 
> Dave


Here's a trust worthy list created by a very reliable source. If it has anything to do with electronic scrap this guy is an amazing source of information. In this video he goes through his top 15 list of CPU's and what he's recovered on average when doing processing them. He lists 2 Pentium's - one of them is ceramic with a gold cap, and one of them is plastic with an a black aluminum heat sink cap. He lists these in his number 2&1 spots for gold recovery at 0.48g and 0.55g respectfully. Check him out. (you can forward to 12:58s if you wish) . ~Kyle


----------



## BlackLabel (Sep 20, 2022)

I'm subscribed to eWaste Bens channel.
I like when he's scrapping exotic devices.
He is scrapping a lot of PCs from 8080 to nearly actual models. He knows a lot but there are some glitches.
I doubt, he did worked all these CPUs and gathered the gold by himself. I've never seen a gold recovery video from him.


----------



## chrundle_the_great (Dec 8, 2022)

Crank said:


> All,
> I should first say thank you to the members here. There really is some great info here for new hobbyist like myself.
> I recently started processing some scrap connectors that have gold pins. To date, I've processed a few different materials all in the hopes of having a lot of foils ready to go. That way I can do batches of aqua regia all at the same time.
> I've stripped some gold plated shields as well a handful of PCBs. They both had one thing in common- when placed in AP, there is a near immediate reaction.
> ...


I did the same thing, I tested my button and it was around 14k the ones I didn't melt I topped the solution with fresh HCI and the pins started to dissolve. Now, I'm doing another batch with some new flat pins added and they're not reacting at all but everything else is. I'm guessing it's just a thicker plating?


----------



## Yggdrasil (Dec 9, 2022)

chrundle_the_great said:


> I did the same thing, I tested my button and it was around 14k the ones I didn't melt I topped the solution with fresh HCI and the pins started to dissolve. Now, I'm doing another batch with some new flat pins added and they're not reacting at all but everything else is. I'm guessing it's just a thicker plating?


If you melt a button from pins you will end up with a very low concentration of Gold and mostly Copper or Kovar depending on what the structure of the pins are made of. Kovar is something that is quite hard to dissolve.
If you do so you will have to dissolve the whole button to liberate the Gold as a fine powder.
If you keep adding flux you can clean up the surface of the button but not much of the alloy.
How do you test it?


----------



## chrundle_the_great (Dec 9, 2022)

Yggdrasil said:


> If you melt a button from pins you will end up with a very low concentration of Gold and mostly Copper or Kovar depending on what the structure of the pins are made of. Kovar is something that is quite hard to dissolve.
> If you do so you will have to dissolve the whole button to liberate the Gold as a fine powder.
> If you keep adding flux you can clean up the surface of the button but not much of the alloy.
> How do you test it?


With a jewelers acid kit


----------



## Yggdrasil (Dec 9, 2022)

chrundle_the_great said:


> With a jewelers acid kit


Ok. 
On this kind of beads that can be quite misleading.
If you hit a high Gold spot it will skew the result.

How much pins and what kind was smelted?


----------



## chrundle_the_great (Dec 9, 2022)

Yggdrasil said:


> Ok.
> On this kind of beads that can be quite misleading.
> If you hit a high Gold spot it will skew the result.
> 
> How much pins and what kind was smelted?


Only a few, enough to make a half gram bead. Out of curiosity I looked at it through my 1000x loupe and you can clearly see gold and copper (guessing I didn't melt enough to fully blend?)


----------

