All out of fingers, now for pins

[nivrnb]

Just going to post some pics of some pins I placed into the AP solution I was using to do my gold fingers. I guess the party is over, because for me the fingers were a great to start. I am not very scientific about my process, what I have done basically, is place a fair amount of pins (in the photos) below into the AP and placed onto air bubbler. I have the time, so I will just let it set until the pins dissolve into the solution and hopefully successfully recover the gold flakes. From reading on the forum when doing pins it is best to do all the same kind of pins.

It has been about one week so far and what has happened is that all the pins are sticking together so I cannot stir them up. I wanted to try out the gold cell, but up until this time the AP process has really worked for me. Will keep ya posted.

nivrnb

 

[Geo]

that is not near enough solution for that amount of metal. you should move it to a gallon container for that amount and increase the solution to at least three quarts. use the solution you have now and increase using fresh hcl and replace the air supply.

i can assure you the base metal is not aluminum.

when processing fingers the major portion of the weight is the fiberglass board, the base metal is maybe double the weight of the foils. with pins, the base metal is almost the entire weight of the material, minus the foils. so if you have 300g of pins then you have 299.7g of base metal. that's alot of metal for that small amount of liquid to digest. when digesting pins, think bigger.

 

[nivrnb]

Thanks Geo, I will use a five gallon bucket, and use more hcl. I am not sure on the base metal of the pins, the reason I thought it was aluminum is because they are very light weight. At the rate that I was going it would have taken a year to dissolve, if not longer. : ( Lessons learned. : )

 

[Geo]

the reason i say it cant be aluminum is, aluminum is VERY reactive to hcl. if you place a piece of aluminum in the solution you have, it would dissolve violently cementing copper like crazy for about a minute and then would be completely gone. if the pins were aluminum, they would have been dissolved in less than an hour, but if i were a betting man (and im not) i would bet the glass would burst from thermal shock because the reaction of that much aluminum with that amount of hcl would generate enough heat to pop it in ten or fifteen minutes. just my opinion.

 

[tek4g63]

I know this is an older post but I have to know. How did things go when you moved to a larger container and added more hydrochloric acid? Did you get your foils? How long did it take?

I always like to see the end result. Thank you.

 

[nivrnb]

tek4g63,

Update to this post, what I ended up doing was this. I left the pins in the small container for over two months. What had happened was that the pins dissolved together, It was copper base on these pins from and old power supply (server). I learned a great deal with this little process, many gold flakes came off and I filtered them. After I learned from Geo that I would need much more HCL for that big of a project, I beleve I maxed out one quart of HCL. What I was left with was a very small amount of gold flakes.

What I have now is half of the pins still in the bottom of the container which have copper dissolved on them in a bright blue color. I am in the process of rejuvanating the AP to continue, and them clean the gold. I bit off more than I could chew with this first attempt.

nivrnb

 

[aaron_cameron408]

I haad some pcb boards with pins like that. When I gotthe green pins after I used a little hcl and it took green off and released more gold flake filtering has been aproblem how did you get the flakes so clean?

 

[nivrnb]

I haad some pcb boards with pins like that. When I gotthe green pins after I used a little hcl and it took green off and released more gold flake filtering has been aproblem how did you get the flakes so clean?

Aaron,

Sorry it took me so long to reply, I hope you read this. What I did to get the gold flakes out of that small container was this. I stirred the container as much as I could to loosen as much of the gold as I could. The pins at the bottom where stuck and did not move. I poured the AP into a beaker, let settle then took and pipette and removed as much of the AP as possible. Then filtered the remaining Gold thru a coffee filter. I didn't clean it that much, just a little, more on that latter.

The pins sat in that container for some time, and after talking with the great folks on this fourm. They told me to (Geo) to use more AP, so what I did was loosened up the pins and placed in a five gallon bucket with the recovered AP and an air bubbler. Which I did until all pins where dissolved.

Now this is the way that I do it. A better way of doing this, and what I have learned was, first pins should be done in a sulfuric cell, secondly cleaning the gold should be done the way (Lazersteve) suggests. What I was told was after you removed most of the AP, the gold needs to be washed with distilled water and hlc over and over again until the color is clear. This is a very big step if you want to get high purity. I hope this helps.

nivrnb