# Hard pin removal made easy



## kurt (Apr 2, 2012)

Removing the pins from this type plastic housing can be hard if not next to impossible. However I have come up with a 3 step process using my router set up in my router table that makes it rather easy. First you make a push stick to hold the pin housing (made mine from a 2X4) then ----

Step (1) run through the router shaving the base close to the pins (wear dust mask) 

Step (2) then use screw diver to brake upper plastic away

Step (3) use pliers to remove pins

Kurt


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## jimdoc (Apr 2, 2012)

That type of connectors looks like the ones that can be split with a screwdriver and a twist.

Jim


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## dtectr (Apr 2, 2012)

The plastic in these is very resistant to acids, I've processed them whole in nitric, and Poor Man's AR, with absolutely no deterioration. I had spent hours, literally, trying to remove these cleanly, which, regardless of how you do it, becomes cost prohibitive, especially if you have a quantity to process. 

From my experience, since these pins are phosphor bronze, which means 6-7% tin, I did these a kilo or 1/2 kilo at a time, using Poor Man's AR, (rather than true nitricin AR) using potassium nitrate. Make sure you add sufficient water to sustain the reaction, and fully react your in-situ nitric production. The gold was VERY pure following first processing, maybe because I took my time, at times taking notes and pictures as I went. 

One batch was so saturated with metals that when I evaporated down to make sure all nitric was dissipated, the gold seperated out and coagulated and floated as a mass on the surface. 

just my dos centavos
dtectr


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## kurt (Apr 3, 2012)

Jim – actually these are different then the ones you are thinking of. I believe the ones you are thinking of are like the one on the left of the picture & yes they brake away with just a screw drive & a twist.

These are in a much heavier plastic housing & a screw driver twist only brakes away the top portion of the plastic & the pins are molded into the base portion so you can not pull them through to get the whole pin.

They all looked like the one on the top right to start with.

So what I have done is first used my bench top band saw with a metal cutting blade to cut off the bottom pins – recovering about a pound of pins per hour (recovered 3 & 3/4 lbs so far in that step

That left me with about 7 lbs of pins still in the plastic housing. These I took to the bench grinder & ran the bottom across the grinding wheel to smooth off the bottom so they would slide clean & easy on the router table (took ½ hour to do this to the 7 lbs)

Then to the router table for the shave of the base side walls – 7 lbs in 1 hour.

Then you can use the screw drive to brake of the top portion of plastic which allows you to then brake the whole pin out of the base with a pliers.

These are molded into a “heavy” bakelite type plastic & are “fully” plated & there is about 3/8 inch of pin you can not recover without first shaving the side wall to brake the pin out. Other wise you can only cut the top portion of that pin off – leaving that 3/8 behind stuck in the base portion of the housing.

Dtectr – these are made of a bakelite type plastic – not sure how they will hold up to the acids – will throw a piece of it in some acid today to see.

I have something like another 30 lbs of these to do. 

Kurt


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## NobleMetalWorks (Apr 3, 2012)

Other ways you might want to try.

Cold/shock treatment, heat it up fast, then dump it in water. It sometimes works with harder material.

Ball Mill, I put anything that can easily break or shatter in my ball mill, then go work on something else for awhile. Sift the fine powder through a sieve or screen and retain all the gold pins.

Throw them in a glass corning dish with a lid, put them on a propane grill until they are nice and hot, then grab each one with a pair of pliers, right out the the corning dish, and pull the pins out with pliers.

Hitting them with a torch, then smacking them with a hammer over a pan so you can catch the pins.

Put them in a grinder, like the crazy crusher, if they are crumbly like Bakelite, they should bust right up.

I have done this so don't laugh too hard. For this stunt you need a pitching machine that allows you to bring the two wheels together close enough so that you can put small items through it. A brick or rock wall, something hard that will not break. A big wide broom, to sweep up the shattered pieces. I think you get the idea. Feed these bad boys through the baseball pitching machine, SPLAT against the brick wall, sweep with the wide broom and process. If you wait to do this when you also are sweeping for sweeps, you get the always well liked, double affect or price of two, for one.

And there you go... Maybe more of a neanderthal approach, but you laughed, I know you laughed.

Okay maybe you didn't laugh, but you get the idea, you can get as complex or as simple as you want. This wrinkled old man once told me, that if you ever wanted to learn the best way to do anything, to watch a lazy person. They will always figure out the easiest way to do any particular job. So I asked my daughter, lol. Know what she told me? She's brilliant by the way. I asked her how I should break something up that was hard to break up. I asked her what she would do, lol, know what she told me? "Dad, why would I do that? I would just ask a boy to do it for me" so your very last option would read more like, why do it yourself if you can get someone else to do it for you? They make a little money, you make a little money, and everyone is happy. I stopped trying to break these apart myself, I try to avoid it at all costs, but I will buy pins that came out of them, to process, so long as the price is fair and I can make a little too. =)


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## kurt (Apr 3, 2012)

SBrown - yes I had a good laugh - or at least a good chuckel.

Anyway - being as how they are bakelite - a jaw crusher to brake them up a bit first then to a ball mill would have been my first idea (I have actually done some hard rock mining) however I don't have ether.

I am thinking stamp mill (make shift) peice of 6 inch pipe about 2 foot long set on end on concrete floor with 1 &1/2 iron rod to mash bakelite inside of pipe with up down motion like tamping dirt around fence post.

Kurt


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## dtectr (Apr 3, 2012)

Sbrown 
None me those methods will work on these connectors- the plastic is very tough and flexible- smashing just makes a wadded up mess. 
ANY abrasion removes gold - put the grinders away! The plating varies between 10 and 20 microns, and it will wear away quickly. 
Kurt - you can bang away trying to find some other method if you want, but you're wasting time and gold, both me which means you're wasting money. I have processed many kilos of these and know of which I speak. Bakelite isn't used for these, as there would be no reason to do so. As resistance to heat is not an issue. Product data sheets are available for these, so how about finding out for sure instead of guessing? You could literally be on your second refining of your gold by now.
If you want yield data, do this - collect enough connectors to equal EXACTLY 1 kilo, count them, divide to reach the number of pieces per kilo, record this. 
Then carefully take apart 3 connectors, keeping the pins from each separate. Weigh each set and record the data. Then combine them and average (for comparison). 
Now all you have to do is weigh or count your connectors to know how many grams or kilos of pins you have to process, as well as how much chemical you will need. After you've finished refining it, all you have to do is divide to determine yield per kilo,


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## NobleMetalWorks (Apr 3, 2012)

dtectr

Good suggestion to look up the material data sheet, when you can find them they can be a huge help.

If he is saying they have a Bakelite consistency, and if a twist of a screwdriver shatters pieces of the sidewall with only a little pressure, it seems to me they are of the brittle variety. If the connectors are old, they tend to be how he describes his. I have processed old connectors, whatever plastic they used back then becomes very brittle with age and then easily shatters when put in a ball mill, or hit with a hammer. I prefer the ball mill because hitting it with a hammer sends parts and pieces flying all over your workshop.

I try not to put anything into solution that doesn't need to be dissolved or consumed by the acids. The reason being is that it takes a lot more acid to strip pins in the connectors, to cover them, than it does to cover just the pins. Because you have all that excess fluid (you have to still keep up the ratios, you don't want to just add H20 until everything is covered with liquid) you have an excess of Nitric to evaporate off, or neutralize, or dilute whatever process you are using. If I am going to have a spill, I would rather a small quantity than a large.

It's true, I have done it. You can process several batches through the same solution until it becomes so saturated and pregnant with heavy metal, that it can no longer consume new connectors put into solution, but now you have to deal with all the solution captured in plastic, you have to rinse those off and save whatever fluid you can spray off them (some of it will contain Au), which adds more water to a process that already has a lot of waste liquid.

The spec sheet may only describe what material the connecters are made of, they may not come even close to describing what the plastic has turned into over maybe 30 years, that is, if they were made in the 80s. Or you might be able to get the specs, if they are still around, then read how time, exposure, oxidation, heat, cold, etc affects them. It would probably be a more scientific approach, and maybe even a better approach, but where is the fun? I took apart a radar system the other day, not because I needed to do it right then, to be honest I'm at a stopping point until I put my equipment together how I want it. But it did calm me, it was a nice stress relief, and I actually enjoyed trying to figure out how to take it apart. Which reminds me, I have some silver braided wire that I wanted to ask how to process best, I'll post pictures later.

On a side note, there are connectors that I pulled off of cables for hospital machines that when immersed in acid, turn very soft (I like to test on a small scale whatever material I am putting into acids). I was lucky I tested on a small scale because after a few short minutes the plastic turned really gooey. I once took a plastic cup I bought at a gas station, filled it with gas because my car had had run out, but before I could walk the gas back, the cup totally dissolved, the gas working as a solvent. It turned into sludge.

I probably don't have near the experience of most of the people posting in this thread, I am very new to all of this. My methods are surely not nearly as refined as people that have done this for years. The very reason I am reading this forum. If I have missed something, or my thinking is somehow flawed, I hope someone corrects me. I only offer my thoughts and observations and whatever little experience I have. I hope I have not offended anyone with my humor.


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## sena (Apr 3, 2012)

process with nitric is the best option ...


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## dtectr (Apr 3, 2012)

Edge card connectors, esp. the black plastic ones will probably survive the next ice age, with little or no deterioration. The grey "hospital-type" are fiber-filled resin - these are molded plastic. Though these were "insert"-type pins, the black ones are often used in cheaper partial plate models which have to withstand the hot chemical bath of plating solution, as some are plated AFTER insertion in the blocks. 
The fully plated pins can be differentiated from the other type by the "nubs" which hold them in place. Another reason why this can't be a brittle plastic is it's need to flex and spring back during the insertion process. 
Sbrown 
I'd like to see your yield results using the ball mill harvesting method - since rusty proved that abrasion can be used as a recovery method, it's a good bet a fair portion of your gold is still somewhere in your mill/debris. Given gold's malleability vs. Nickel's lack of it, it's more likely to be "stretched" off the pin by the repeated pounding in the mill than it is to be revealed by it. 
Do what you want - but the science is fairly sound. I'm just saying that a good portion of your gold is either embedded in a grindstone or smeared inside your mill some where- IMHO


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## NobleMetalWorks (Apr 3, 2012)

All good and valid points, it would be interesting to take each method, run exact amounts of the same material and see which yields the most, is more cost effective and took less time. I use my ball mill for a lot of different material, the inside is about as impregnated with ceramic as it can possibly be, so I doubt I am loosing any values along the inside of the mill. You are right, there are small values that are sometimes left in the milled powder, for those I just simply run the powder separately from the other material, at the very least I use far less solution. I always dissolve a small amount of whatever I am throwing away, in AR, and test with Stannous Chloride to make sure I am not loosing any PM in waste material. There are some things I have found that contain Au suspended in the dust, and other things not at all. Just depends on your mill, your milling balls, the material you are milling, etc etc etc. I can mill something and get very different results than someone else milling the same thing using different equipment, or even different times. Some items I only need broke up enough to get the PM bearing material out, which means it never goes to powder, but rather pieces that I can then easily sort with sifting screens or by hand.

We should keep suggesting new and improved, or old, tried and true ways of processing material. I have learned a lot just reading and discussing this thread, myself. Every post in this thread is valid.


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## kurt (Apr 4, 2012)

Nothing better then a good round table discussion with a bunch of intelligent innovative minded guys to keep the blood flowing – gota love it!!!

dtectr – I have actually tried your method. Last year I striped 400 lbs of mother boards which gave me a “bunch” of pin in the plastic like those on the left of the picture. I took something like 5 or 6 of them & put them in nitric to see how the plastic would responded to the acid. Like the one in the middle there was no effect on the plastic by the acid. (note – by appearance they were all the same black plastic) 

So I then put the “whole bunch” in nitric & when I checked on them a bit later noticed that some (5 – 10%) were being attacked & braking down by the acid like the one on the right (the middle one & the one on the right are actually the plastic from that batch)

As soon as I saw that happening I poured the acid off & spent a bunch of time picking though them to remove the ones that were being affected by the acid before they made a real mess in the whole batch. Put the good ones back in the acid & finished processing them & processed the bad ones as a batch of there own.

So yes – this method can & does work – but it is not entirely with out problems – at least in my experience with it – so although I am not entirely turn off by it – I am not entirely sold on it ether.

These that I am currently working with are in fact a VERY brittle plastic. Yesterday I gave my make shift stamp mill idea a try on a few of these & the bottom picture is the result of one (one used for showing results) & at this point I am thinking “for this case” milling is the way to go.

Kurt


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## NobleMetalWorks (Apr 4, 2012)

Thank you for the pictures and explanation.


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## dtectr (Apr 4, 2012)

That is exactly my motive in this thread, gentlemen. I have benefited as well. I usually post less for us with some experience than I do for those with little or none. Hopefully a newbie will read this and benefit from our collective experiences! 
Keep us posted. 
The connector that began to decompose - was it a dark green? I had some old ones made from pthalene that behaved that way. I have to use my phone for inet access so photos are hard to see, sometimes.


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## goldsilverpro (Apr 4, 2012)

dtectr said:


> The plating varies between 10 and 20 microns, and it will wear away quickly.



I assume you meant to say microinches and not microns.


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## dtectr (Apr 4, 2012)

goldsilverpro said:


> dtectr said:
> 
> 
> > The plating varies between 10 and 20 microns, and it will wear away quickly.
> ...


 I did, indeed. Thanks, chris. 
On that note may I recommend GSP's book for a thorough and easy to understand explanation of the difference, why it matters and figuring and determining plating thicknesses, as well as estimating yields.
Edit - spelling


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## kurt (Apr 5, 2012)

dtectr said:


> The connector that began to decompose - was it a dark green? I had some old ones made from pthalene that behaved that way. I have to use my phone for inet access so photos are hard to see, sometimes.



No - they were all black - if the connector was the same type connector but a a different color plastic I did an acid test on a few of that color plastic first

Kurt


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## drlakic (Apr 23, 2013)

Hi everyone,

There is no need to remove pins from the plastic. You can do electrolysis with a pins in the plastic. Just insert copper plate to fit in between bottom rows of a pins so each of them is connected to the copper plate. Wash them of in a bucket of water and then combine precipitated gold with one from sulfuric acid. Refine it once again and the job is done.
Maybe I am little out of date, but it might help someone in a future.

Drazen


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## kurt (Apr 29, 2013)

drlakic said:


> Hi everyone,
> 
> There is no need to remove pins from the plastic. You can do electrolysis with a pins in the plastic. Just insert copper plate to fit in between bottom rows of a pins so each of them is connected to the copper plate. Wash them of in a bucket of water and then combine precipitated gold with one from sulfuric acid. Refine it once again and the job is done.
> Maybe I am little out of date, but it might help someone in a future.
> ...



This may work on a small batch level (few pounds) but I don't think it would work if you are working on a 55 gallon barrel (or 2 or 3) full of pins - back when I posted this it was a 55 gallon barrel that I was working on

Kurt


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## kjavanb123 (May 6, 2013)

All,

So grind ball mill then magnet separation would be the wise choice when scrapping pins from a ton of PCBs?

Thanks
Kevin


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## Geo (May 6, 2013)

kjavanb123 said:


> All,
> 
> So grind ball mill then magnet separation would be the wise choice when scrapping pins from a ton of PCBs?
> 
> ...



this will work for HDPE but low density plastic would be a nightmare in a ball mill. the soft plastic has a lower melting point and the action of the mill generates enough heat to soften it even more. this will cause it to smear and create lumps fouling the mill and the charge. low density plastic should be removed before milling.


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## kjavanb123 (May 6, 2013)

Geo,

Thanks for your respond, please advise if you refer to PCI sockets or memory sockets as HDPE type plastic cover? how would you recognize with plastic would not stand the heat produced in the ball mill? I have a plastic shredder in the shop i will be working, would that be better than ball mill to do the job of separating the pins from the plastic cover?

Thanks
Kevin


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## Geo (May 6, 2013)

the best i can tell you is most slot connectors that the PCI cards (with fingers) plug into is high density plastic as it tends to break before it bends very far. the connectors that ribbon cables plug into are low density plastic as they can be twisted double without breaking. breaking can be a good test, if the plastic breaks before it bends, it can be milled. if the plastic can be bent without breaking, it can not be milled.


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