An amazingly thick piece of gold plating!

[Alondro]

Found this one foil from a ceramic part that is almost absurdly thick! Don't know what the part was from, but one whole side was just this big piece of gold foil, thicker than lab-grade aluminum foil (which is like 4 sheets of regular grocery store foil thick). I estimate that it's about half a gram!



I'll be posting more vids in the coming weeks. I'm starting my foils refining with the HCl-bleach method. The first test was a resounding success, and the foils I have mixed up in a 500ml beaker in a shredded mass of incinerated, base-metal cleared circuit boards (I got a bunch of very old ones) have so much gold, I initially thought the reaction had failed because it looked like nothing dissolved. But when I did the drop, it looks like 2 grams dissolved... and the mass of fiber in the beaker is still FULL of gold foil bits! The recovery looks like it will be WAY above what I expected!

 

[macfixer01]

Found this one foil from a ceramic part that is almost absurdly thick! Don't know what the part was from, but one whole side was just this big piece of gold foil, thicker than lab-grade aluminum foil (which is like 4 sheets of regular grocery store foil thick). I estimate that it's about half a gram!



I'll be posting more vids in the coming weeks. I'm starting my foils refining with the HCl-bleach method. The first test was a resounding success, and the foils I have mixed up in a 500ml beaker in a shredded mass of incinerated, base-metal cleared circuit boards (I got a bunch of very old ones) have so much gold, I initially thought the reaction had failed because it looked like nothing dissolved. But when I did the drop, it looks like 2 grams dissolved... and the mass of fiber in the beaker is still FULL of gold foil bits! The recovery looks like it will be WAY above what I expected!

Do you have a picture of the component, or of the board with the component on it?

 

[orvi]

Found this one foil from a ceramic part that is almost absurdly thick! Don't know what the part was from, but one whole side was just this big piece of gold foil, thicker than lab-grade aluminum foil (which is like 4 sheets of regular grocery store foil thick). I estimate that it's about half a gram!



I'll be posting more vids in the coming weeks. I'm starting my foils refining with the HCl-bleach method. The first test was a resounding success, and the foils I have mixed up in a 500ml beaker in a shredded mass of incinerated, base-metal cleared circuit boards (I got a bunch of very old ones) have so much gold, I initially thought the reaction had failed because it looked like nothing dissolved. But when I did the drop, it looks like 2 grams dissolved... and the mass of fiber in the beaker is still FULL of gold foil bits! The recovery looks like it will be WAY above what I expected!

We routinely "measured" the thickness of plating by zapping with XRF and estimating from % reading on precious metals mode. It was different from matrix to matrix (different readings for brass/bronze/FeNi alloys/NiCuZn etc.), but usual rule of thumb for pins was number 3 for regular average pins, 3% gold reading equaled 1g/kg Au. Yeah, depends on the surface to metal ratio and other factors, but it kinda always worked for ballpark estimate (lowgrade vs. midgrade vs. highgrade). And it was relatively steady up to like 40-50%Au reading, then it started to be quite off.

My point was - if you had a part, and the reading shown only gold, and nothing else, you opened the bottle of champagne usually this stuff was super super rich. Like some parts from aviation boards and stuff, and also scientific equipment special measuring stuff. Same... Shot with XRF, nothing else than gold on the reading that was the moment you knew it will be good. Also WAl and MoAl alloy circles with silicon wafer, both sides plated - parts removed from high power diodes or triacs/thyristors. Plating that thick that I2/KI "removing session" took over an hour

Foil that you show will easily fall to this category.

 

[Alondro]

Do you have a picture of the component, or of the board with the component on it?

Nope, it was all in a batch of mixed parts that got soaked in HCl at the same time. They were discarded some time ago.

I think I have one more part like it somewhere, but it's in a large bin of stuff.

 

[justinhcase]

I think you will find it is actually a foil that is applied rather than plating.
I have had scrap foil leftovers from dental technicians in Pt and Au that they apply to ceramics.

 

[Alondro]

I think you will find it is actually a foil that is applied rather than plating.
I have had scrap foil leftovers from dental technicians in Pt and Au that they apply to ceramics.

Quite possibly, but it's still odd to find a part with such thick foil on it. It was so thick, my HCl-bleach method couldn't dissolve it completely even after 5 minutes, while the rest of the foils dissolved in seconds.