Bought this thing, I think it's gold...but it's so big!

[24carrotdong]

Hi everyone! Thank you for creating and maintaining this forum. It is a godsend. King Midus would be very pleased, though he wouldn't find much use for the information...obviously.

I got this item at an auction and I think it's gold plated. It's just so big and I got it so cheap, I have a hard time believing it's legit. I'm not ready to recover and refine yet (still working my way through Hokes book for the 2nd or 3rd time), just collecting scrap building up my war chest.

I used a test kit and I'd like some help interpreting the results. Only the 22kt solution created a reaction, which is promising. Here are the pics:
(The item is a Coherent laser power something...so it's not out of the question for gold plating to be present.)

The two pools are 18k on the left and 22k on the right. The pictures don't do it justice, but the 22k liquid is clearly yellowed while nothing has happened with 18k for some time (same for 10k and 14k). Picture 4 is where I rubbed the test slab. I used a knife to cut to see the color of the bulk vs. surface material. It is non-yellow metal, so the surface is definitely a coating/plating. I'm familiar with anodic coatings and this is not that. I suppose a key question would be: is there a gold-like material used as a coating that is only dissolved by 22k test liquid? My first thought was beryllium, but ruled that out immediately based on my experience working with it.

Anywho, any insight would be much appreciated.

Thank you.

DarrenZ

 

[snoman701]

Looks like aluminum, but given the subject matter could also be a stainless like material.

 

[nickvc]

The company is US based so just give them a call and ask what it is and what it’s made of , depending on the substrate we can advise how to recover what looks to me to be gold.

 

[war_child]

Hello 24. I don't have any experience with that type of material, but I do believe gold is commonly used in RF shielded equipment. Use the search bar to research the topic on this forum. You may even find some pictures of similar equipment. I searched something like: "gold rf plating" and checked the first few threads. I haven't learned to share links, but I copied it. Hopefully you can copy and paste it.

https://goldrefiningforum.com/threads/anyone-familiar-with-farran-radar-products.10106/#post-97265
Do you work with nitric acid at all? If you could dissolve the gold fillings, you could probably test with stannous. Though I don't know if you need to treat the base metal first, or what the correct process would be. I think HCL dissolves aluminum; I wonder if you could eat away the aluminum (if it even is Al) and melt the remaining gold, If any.

That's just the thoughts or an unlearned rookie, mind you. Do your due diligence & reseach before you work with acids & treat waste material.

Good Luck!
mike

 

[orvi]

Hi everyone! Thank you for creating and maintaining this forum. It is a godsend. King Midus would be very pleased, though he wouldn't find much use for the information...obviously.

I got this item at an auction and I think it's gold plated. It's just so big and I got it so cheap, I have a hard time believing it's legit. I'm not ready to recover and refine yet (still working my way through Hokes book for the 2nd or 3rd time), just collecting scrap building up my war chest.

I used a test kit and I'd like some help interpreting the results. Only the 22kt solution created a reaction, which is promising. Here are the pics:
(The item is a Coherent laser power something...so it's not out of the question for gold plating to be present.)

The two pools are 18k on the left and 22k on the right. The pictures don't do it justice, but the 22k liquid is clearly yellowed while nothing has happened with 18k for some time (same for 10k and 14k). Picture 4 is where I rubbed the test slab. I used a knife to cut to see the color of the bulk vs. surface material. It is non-yellow metal, so the surface is definitely a coating/plating. I'm familiar with anodic coatings and this is not that. I suppose a key question would be: is there a gold-like material used as a coating that is only dissolved by 22k test liquid? My first thought was beryllium, but ruled that out immediately based on my experience working with it.

Anywho, any insight would be much appreciated.

Thank you.

DarrenZ

Scrape small area (like 1cm2) to the test vial, add few drops of HCl and observe how it behave - if it start to fizz very violently, it is most probably aluminium. Stainless would not react so fast, and if it will - resulting solution will be greenish-brownish-yellowish coloured. Gold would be unaffected.
Then drop few drops of HNO3. If there is gold, it will slowly dissolve. Then test it with stannous chloride test.

Theoretically, it could be some type of gold braze, AuSn20 or other possibilities. But on aluminium, I don´t know if this type of coating could be used.

Doable within one hour. If it is gold plated, lucky find

PS: where did you work with beryllium ? if it is not top secret

 

[24carrotdong]

Scrape small area (like 1cm2) to the test vial, add few drops of HCl and observe how it behave - if it start to fizz very violently, it is most probably aluminium. Stainless would not react so fast, and if it will - resulting solution will be greenish-brownish-yellowish coloured. Gold would be unaffected.
Then drop few drops of HNO3. If there is gold, it will slowly dissolve. Then test it with stannous chloride test.

Theoretically, it could be some type of gold braze, AuSn20 or other possibilities. But on aluminium, I don´t know if this type of coating could be used.

Doable within one hour. If it is gold plated, lucky find

PS: where did you work with beryllium ? if it is not top secret

I used to design infrared and low light optical systems for the army (semi-top secret). I've seen a few beryllium optics (like jwst, just smaller) and a lot of beryllium-copper alloys as electrical spring contacts...enough to recognize it.

There are definitely quite a few pieces that are definitely plated (pins, connectors, etc). I paid $60 and I see a few on eBay going for $150-$200. I'd rather keep it and gain the experience of exploring the different parts. Even the wires are something I've never seen...if I had to guess, they look like platinum (very silvery white, like the hair of platinum blond Barbie).

Thanks for the reply, I'll investigate and report back.

 

[24carrotdong]

Hello 24. I don't have any experience with that type of material, but I do believe gold is commonly used in RF shielded equipment. Use the search bar to research the topic on this forum. You may even find some pictures of similar equipment. I searched something like: "gold rf plating" and checked the first few threads. I haven't learned to share links, but I copied it. Hopefully you can copy and paste it.

https://goldrefiningforum.com/threads/anyone-familiar-with-farran-radar-products.10106/#post-97265
Do you work with nitric acid at all? If you could dissolve the gold fillings, you could probably test with stannous. Though I don't know if you need to treat the base metal first, or what the correct process would be. I think HCL dissolves aluminum; I wonder if you could eat away the aluminum (if it even is Al) and melt the remaining gold, If any.

That's just the thoughts or an unlearned rookie, mind you. Do your due diligence & reseach before you work with acids & treat waste material.

Good Luck!
mike

Based on my attempts to scrape it with a steel blade, I don't think it's aluminum. The blade did not dig like in aluminum and the knife edge yielded almost immediately - it's not magnetic either. The weigh is 4 lbs. I'll investigate and report back. I have a few avenues to explore that will likely give me solid answers.

Thank you!

 

[butcher]

File a few flakes into a test tube and test it.

 

[Geo]

Dilute nitric acid bath should loosen the gold in big sheets. It will have to dissolve the nickel and copper layer under the gold. As long as the box is not copper or brass, the gold should come off cleanly.

 

[orvi]

I used to design infrared and low light optical systems for the army (semi-top secret). I've seen a few beryllium optics (like jwst, just smaller) and a lot of beryllium-copper alloys as electrical spring contacts...enough to recognize it.

There are definitely quite a few pieces that are definitely plated (pins, connectors, etc). I paid $60 and I see a few on eBay going for $150-$200. I'd rather keep it and gain the experience of exploring the different parts. Even the wires are something I've never seen...if I had to guess, they look like platinum (very silvery white, like the hair of platinum blond Barbie).

Thanks for the reply, I'll investigate and report back.

Nice

I was always quite afraid of beryllium.

Platinum is extremely soft compared to regular Ag or Ni plated copper wire. And do not dissolve in nitric as is. Not used on many occasions in electronics, there are better alternatives for good conductivity wires.

 

[orvi]

Based on my attempts to scrape it with a steel blade, I don't think it's aluminum. The blade did not dig like in aluminum and the knife edge yielded almost immediately - it's not magnetic either. The weigh is 4 lbs. I'll investigate and report back. I have a few avenues to explore that will likely give me solid answers.

Thank you!

File off some bits and test with nitric acid. If it won´t react, it is probably some aluminium, titanium alloy or stainless steel. With that weight, maybe closer to titanium (half-way density between aluminium and iron/stainless).
If you drop some HCl into the nitric with filings, and it start to colour the solution to greenish-yellowish colour, it is probably stainless. Or something more exotic, considering some special applications
Titanium and aluminium reacts with HCl alone, bubbling H2 gas.

 

[24carrotdong]

Nice

I was always quite afraid of beryllium.

Platinum is extremely soft compared to regular Ag or Ni plated copper wire. And do not dissolve in nitric as is. Not used on many occasions in electronics, there are better alternatives for good conductivity wires.

Yeah, no grinding beryllium in my breathing air! Luckily, only a small % of the population is susceptible tio berylliosis.

Upon further examination, it seems like silver plating.

I further cut into the main housing and dropped a few drops of the 22k test solution on it. The reaction varied. On the gold colored metal, it turned a dark brown/black. On the cut pieces with bare metal exposed, a light colored, whitish precipitate formed.

I'm not set up to safely open the nitric bottles yet. Once I finish my hood, it's game time.

 

[MicheleM]

@24carrotdong could I ask you for some advice?

 

[TK421]

The item is a Coherent laser power something...

It's a very powerful laser diode, likely used for marking containers or long-distance fiber optic communication lines.

Any chance you still have the components inside it? For people like me who play with lasers, it's worth more than its gold plating (if it still works - these are frequently replaced when they burn out).

Don't bother calling Coherent. I used to work with their products, and unless you have a (very expensive) service contract with a dedicated phone number, they won't even answer the phone. Their sales line will, but those guys don't know much about their products. They know key words and buzz words, and how to push their products. They don't have a clue how they work or how they're made.

The outer shell is most likely gold-plated. The inner device is anodized aluminum. There might be gold bonding wires on the laser diode itself, but they will be embedded in epoxy, and I'd be surprised if they contained more than a few milligrams of gold between them. We're talking about nearly microscopic wires, similar to IC/CPU jumper/bonding wires.

If you just want to get money out of your investment, you'll likely get more on eBay for the laser diode than all the gold on the device. If you can verify it works, it could be worth $50 or so. BUT - DO NOT try to power it up yourself. A 35 watt laser is enough to blind you in microseconds - faster than you can blink, and you don't have to be looking at the beam. A reflection off of a painted wall or window is all it would take, and I'm fairly sure that's an infrared diode, so you can't see the beam anyway.

 

[BShan]

806nm IR diode, 40W (optical output?!?!), fast axis corrected. It's like a stack of smaller diodes, with a tiny optic on the front to make the beam more round. Neat! Even without optics to form a parallel beam, this device can output too much light from too small of a source, and as TK421 mentioned, shouldn't be powered on without appropriate safety measures.

Diodes this big may not even use bond wires. Probably will find more gold plated copper blocks inside, while the chips themselves may be soldered onto the block with a lower temp solder or metal. Chips themselves will be made of gallium arsenide semiconductor.