FINGER HAULIN

[oldgoldman]

Yesterday's bonus way way at the bottom of a 5,000 lb pile of $hi#. Going to buzz these later .. 1996 vintage I suspect.

 

[kuma]

Hi Oldgoldman , how are tricks?
I hope your well!
Very nice haul chief , keep us posted!
All the best with them , and kind regards for now ,
Chris :mrgreen:

 

[jeneje]

Very nice indeed, have fun with them. :lol:
Ken

 

[oldgoldman]

My tricks are :

1. Don't tell anyone your tricks ..
2. Act with urgency .. you have to be able to drop everything if an opportunity for material capture arises
3. Often the best material in large dumps are at the bottom .. be patient

Here are some HP double finger cards that I hauled yesterday also. Lots more of these in the pile.

Regards

 

[Geo]

i suspect the cards in the last picture is gold plated on all traces. remove some of the solder mask and check it out.

 

[oldgoldman]

Thank you for the information .. Exactly where should I check and what is best quick way to remove the solder area ? .. Do you think these would yield above RAM ?? .. little food for thought ..

 

[Geo]

you can gently scratch off a small area of the green to see if the gold extends underneath the solder mask (solder mask is the green coating on the board). most older boards that have gold plating on all the exposed areas will most often be plated all the way across.if they are, think of it as one big finger connector with roughly the same yields. if it is plated all the way across, remove the solder mask with warm caustic soda bath less than 100°C for a few minutes and then rinse with cool water. wear gloves and eye protection. this can be done indoors but be very careful of spills as it will dissolve aluminum very quickly.

 

[Michael kilgore]

I'm a newbie,i wanted to soak off my gold finders,but the all got dissolved in the nitrate acid.i also have more finders i would to remove,the fingerfrom the board.what shothat has dissoud i do with this acid that lved in it.shoud i treat like aqua regia?or make it into aqua regia by adding muriatic acid,then rest of my finger the keep on dissolving the rest of my fingers? thanks michael

 

[maynman1751]

In the first place you shouldn't be using nitric to process fingers. HCl/AP is best for those. It will dissolve the base metals and leave the fingers as flakes. Then after a rinse in hot HCl you can dissolve in HCl/Cl. Have you read Hokes book yet. If not start there and you will be better acquainted with the proper processes. I think that you could just de-nox the nitric and cement the gold out with copper. Wait for someone else to answer that one....I'm not sure as I haven't used nitric as of yet. Read and study more before taking on things that you don't have the knowledge for. Search the forum for answers. Also, take the Guided Tour . The directions are on LazerSteves signature line. Just my 2 cents!

 

[Harold_V]

I'm a newbie,i wanted to soak off my gold finders,but the all got dissolved in the nitrate acid.i also have more finders i would to remove,the fingerfrom the board.what shothat has dissoud i do with this acid that lved in it.shoud i treat like aqua regia?or make it into aqua regia by adding muriatic acid,then rest of my finger the keep on dissolving the rest of my fingers? thanks michael

I wonder-----did you read what you posted? It makes very little sense.

I'm not trying to be rude, but you must use proper language here--otherwise you're going to get suggestions that may not be in your best interest. Speak in clear, concise English, to the best of your ability. If English is not your first language, make that clear, so we can ask for clarification on subjects that may not be clear to us. Getting advise for unrelated subjects isn't a good idea.

Harold

 

[oldgoldman]

yesterday's haul .. 220 lbs worth .. i do not believe they are fully plated .. i did scrape some mask off .. thanks for the advice.. still a nice pile though ..

 

[Smack]

If there is gold under the solder mask it will scrape off real easy. Just a quick look at those in the pic's and I would say not gold under the mask.

One thing I have noticed over the years is that the PCB's that do have gold under the mask are almost always the real green ones and not the brown or gold looking ones.

 

[Geo]

theres still alot of gold plate on the middle of the boards and not just the fingers. in my opinion, it would totally be worth processing the whole board. those gold plated dots add up.

 

[schomisch]

I agree with Geo, just from the boards shown in the pictures there is gold in the middle of the boards also. Not to mention if your going to be processing the 'Dots' you might as well save yourself some work and time of cutting some fingers, and run them whole. =))

~Chris!~