AP suitable components/material

[MooseMan]

Hi All

After lots and lots of reading since I joined early this year to educate myself, I'm hoping that I have enough time over the Xmas holidays to prep a few kgs of material for an AP run. I'll do a small test run first of course.

I have lots of boards and RAM that I'll remove all of the fingers from, but are there any other components/parts that I can safely mix into the trimmed fingers, to strip the foils from? I have quite a lot of small bare pins and plated connectors, woud it be wise to include some of these, for example?

I'm going to totally segregate all board components, chips, north and south bridge etc for later processing when I feel ready, but if there is anything that I can add to the fingers in the AP that won't mess up the process I'd appreciate the heads up?

I'll take photo's of my process when I eventually get going, and start a thread on it, but if there is any sage advice for me before I get this started I'm all ears. I have probably read every thread on this forum that discusses AP and stripping foils, but always open to any "New" advice that is offered.

 

[FrugalRefiner]

While AP will work on both fingers and plated pins, I would keep them separate. The fingers will process quickly and release their foils because the copper underneath them is very thin and will dissolve pretty easily. Pins, on the other hand, have a lot of base metal compared to the thickness of the plating, so they require a much longer time to completely dissolve the base metal.

Dave

 

[MooseMan]

Thanks Dave, I've read exactly this regarding pins, but just wanted to ask before I get things started off in case there are things that I could be adding to my AP bucket with the fingers and other Gold bearing board trimmings.

Appreciate you responding to me so quickly in any case, thank you.

 

[orvi]

Thanks Dave, I've read exactly this regarding pins, but just wanted to ask before I get things started off in case there are things that I could be adding to my AP bucket with the fingers and other Gold bearing board trimmings.

Appreciate you responding to me so quickly in any case, thank you.

AP solution works better on copper based material rather than nickel or kovar. Due to this fact, if the speed is your concern somehow, you can separate magnetic and non-magnetic pins and run them separately if you want.
Otherwise, it is just a matter of time. If the time is not your primary concern, you can mix whatever you want to the AP - regarding pins, trimmings, fingers, other plated stuff... But you need to be prepared for the eventual weeks long dissolution of thicker pins, or pins made of kovar.
Also, thick plated rich pins are quite a pain to process thorugh AP - when the plating is thick, acid cannot access base metal underneath the gold easily - thus resulting in very long dissolution times, and sometimes, pins are removed completely intact. If you still want to process them by AP, you need to somehow cut them or brush the surface of them, revealing the base metal even on the small area.
But with good pins, I go directly to AR. Or if you have access to cheap nitric, go ahead and use straight nitric to remove the base metals. This is probably the most convenient route of processing non-magnetic pins.

 

[MooseMan]

Thank you Orvi for such a considered reply.

I certainly am in no rush, I've been prepping for this since march when I joined, so time is not one of my concerns here at all!
In fact I'd much prefer a situation where I could have one or two buckets with parts in AP that I could almost set and forget, apart from the odd shake. I intend to add the very minimum of peroxide to get the process going in fact.
(I read an old thread where one of the more experienced members recommended adding an equal quantity of water to the AP in order to leave it for extended lengths of time, and that even with the peroxide addition the AP would not dissolve any or very, very little gold, just the copper. Does this still stand?)

I'll be sure to follow your advice in regards to magnetic and non magnetic pins as I have quite a variety, so I'll separate them in any case.

I was thinking I could also put in things like gold plated ends snipped from LCD ribbon connectors, printer cartridge gold contacts, sim/SD contacts, USB stick contacts that kind of thing.

And also, possibly CPUs with gold plated faces?