Question about gold plated pins

[coincard]

I recently purchased 125 Siemens industrial PLC boards, the kind they use to run automation equipment. The boards that had Cpus on them had 386 and 486 processors so they have been around for a while.

All of the boards had at least 2 and some had 3 or 4 IDE type connectors on the boards (see photo 1). On normal type boards I would use a steel putty knife and and cut the connectors off of the board which would leave a clean pin I just had to pull from the holder. These boards that does not work on, I have been heating them on a hot plate and pulling the entire connector pins and all off of the board, I would then pull the pins ( photo 2) and then clip the pin off where the plating stops (photo 3).

As you can imagine it takes some time to do all of that and my fingers and thumb are wore out and I have several hundred connectors to do yet. My question is if I am going to process these in a sulfuric acid stripping cell to I really need to clip them off at the plating or can I just put the entire pin in and strip it that way ( photo 4) ?

Would the solder on the ends of the pins cause problems? This is new to me and I do not want to make my first attempt harder that it has to be. Any info would be appreciated....


Dave

 

[Rreyes097]

I've processed those before! But I ended up using a less effective method being HCL and peroxide. But I think the sulfuric acid cell is best. But no you don't have to cut the pins. But I believe you would be better off to make sure they are out of the white plastic casing they are in. As for the solder. I don't think it would be a problem but I can't say for certain.

 

[coincard]

Thank you for the reply, If I can at least eliminate the cutting them down part that would save some labor. I thought about the AP solution and was going to go that route but then I seen the acid cell and that seems to be the way to go with plated items....

 

[Martijn]

If you have all the pins out of the plastic the sulfuric cell is the best way imo.

Hello, I've made a video of how I stripped my first kilo's of gold plated connector pins.
It shows the stripping process, diluting the acid, dissolving in AR, SMB precipitation with an excess of nitric and the end result.
I had to leave a lot of parts out... I was amazed how much I was touching things back then without gloves while putting this video together

I hope you enjoy it and find it informative.
Let me know what you think.



Martijn.

I found out that prying a long flat screwdriver in between the rows of pins gets the plastic from the pins leaving them on the board. You can then wiggle them off until they break, without solder on the ends.
Put the connector in a vice and push the screwdriver in. Pry open each row separately, a couple of pins at a time.

But if the pins are still in the plastic and off the boards, you could go straight for AP.
I tossed a bunch of exactly those control cards connectors in AP and they came out clean after some rinsing. All the copper was eaten out. That plastic does not dissolve in AP.

Not sure if solder in AP is a big problem, some members toss whole boards in AP.
I have also done it once and haven't had any problems with that batch.

Martijn.

 

[Shark]

That white plastic becomes a real mess in AP. It starts to break down in a sticky goo.

 

[coincard]

They make a mess on a hot plate as well, getting the plastic off is not that big of a deal but I do not know what kind of solder they used on these boards, most of the traces are silver in color, so who knows what the solder is made of.

as near as i can tell these boards are from the late 80s to the mid 90s there were a ton of IC chips and lots with gold legs as well as gold colored eproms, but for now I just really need to know if the solder on the ends of the pins will cause issues in the acid cell.

Thank you everyone for your input...

 

[Alondro]

If you have all the pins out of the plastic the sulfuric cell is the best way imo.



I found out that prying a long flat screwdriver in between the rows of pins gets the plastic from the pins leaving them on the board. You can then wiggle them off until they break, without solder on the ends.
Put the connector in a vice and push the screwdriver in. Pry open each row separately, a couple of pins at a time.

But if the pins are still in the plastic and off the boards, you could go straight for AP.
I tossed a bunch of exactly those control cards connectors in AP and they came out clean after some rinsing. All the copper was eaten out. That plastic does not dissolve in AP.

Not sure if solder in AP is a big problem, some members toss whole boards in AP.
I have also done it once and haven't had any problems with that batch.

Martijn.

I made a couple vids on Rumble showing how to pop the plastic quickly off a couple types of pin arrays. Some can be tricky, depending on how they're assembled.

 

[coincard]

If you have all the pins out of the plastic the sulfuric cell is the best way imo.



I found out that prying a long flat screwdriver in between the rows of pins gets the plastic from the pins leaving them on the board. You can then wiggle them off until they break, without solder on the ends.
Put the connector in a vice and push the screwdriver in. Pry open each row separately, a couple of pins at a time.

But if the pins are still in the plastic and off the boards, you could go straight for AP.
I tossed a bunch of exactly those control cards connectors in AP and they came out clean after some rinsing. All the copper was eaten out. That plastic does not dissolve in AP.

Not sure if solder in AP is a big problem, some members toss whole boards in AP.
I have also done it once and haven't had any problems with that batch.

Martijn.

I made a couple vids on Rumble showing how to pop the plastic quickly off a couple types of pin arrays. Some can be tricky, depending on how they're assembled.

These are a real pain, the pins are all on an angle and they do not like to be pried on, using a stiff metal putty knife works really well on regular boards as you can cut right through the pins at the bottom of the connector along the board, but these are much stiffer base metal and they twist and bend into a mess trying that method which is why I went to melting the solder joints and pulling it off.

I will check out your vids on Rumble and will try what Martijn suggested earlier and see if those work better.

Thank you for the reply....

 

[Alondro]

These are a real pain, the pins are all on an angle and they do not like to be pried on, using a stiff metal putty knife works really well on regular boards as you can cut right through the pins at the bottom of the connector along the board, but these are much stiffer base metal and they twist and bend into a mess trying that method which is why I went to melting the solder joints and pulling it off.

I will check out your vids on Rumble and will try what Martijn suggested earlier and see if those work better.

Thank you for the reply....

Search 'Alondro77' on Rumble. That'll bring up my vids.

 

[Ohiogoldfever]

I have processed many connectors. Nothing that looks similar.

I would put them in a SS container and burn them.

Keep the heat low and keep them covered. If done correctly you can smash the plastic letting go of the pins.

 

[Rreyes097]

I used old pair of nail clippers worked well and was able to pull multiple pins at once. But then mine were free of any solder or anything at all.

 

[BlackLabel]

Depending on the boards, you could use the naked blade of a metal saw (about 10 inch). If there is enough space beside the connector, cut them right along the board's surface.
If it works, you could build a handle for the blade using duct tape.

 

[Seny2021]

I recently purchased 125 Siemens industrial PLC boards, the kind they use to run automation equipment. The boards that had Cpus on them had 386 and 486 processors so they have been around for a while.

All of the boards had at least 2 and some had 3 or 4 IDE type connectors on the boards (see photo 1). On normal type boards I would use a steel putty knife and and cut the connectors off of the board which would leave a clean pin I just had to pull from the holder. These boards that does not work on, I have been heating them on a hot plate and pulling the entire connector pins and all off of the board, I would then pull the pins ( photo 2) and then clip the pin off where the plating stops (photo 3).

As you can imagine it takes some time to do all of that and my fingers and thumb are wore out and I have several hundred connectors to do yet. My question is if I am going to process these in a sulfuric acid stripping cell to I really need to clip them off at the plating or can I just put the entire pin in and strip it that way ( photo 4) ?

Would the solder on the ends of the pins cause problems? This is new to me and I do not want to make my first attempt harder that it has to be. Any info would be appreciated....


Dave



View attachment 52420View attachment 52421View attachment 52422View attachment 52423

We busyremoving normal pins from DVD roms and IDE hard drives using a hammer to smash the plastic and manually removing the pins but I'm not sure if it will work with that it look very much thick

 

[Shark]

Most of the white connectors like those pictured are soft and won’t break apart. I unsoldered them and pulled the pins using cheap Harbor Freight flush cutters or those from Walmart.

 

[Martijn]

That white plastic becomes a real mess in AP. It starts to break down in a sticky goo.

Not with me. Strange. I could pull them out and spray rinse them off.
Ive seen two types of connectors on these control boards.
One hard and white plastic, like in his picture.
The other a softer, slightly transparent plastic. Both went just fine in my AP process. But give it a try with one connector in a small cup. See for yourself.
Prying the plastic off, while keeping the pins on the board is the best thing imo.

I now only treat real motherboard socket pins in AP. They are too thin to put in a copper basket in the H2SO4 cell.
The thicker ones from industrial control systems take a lot longer to dissolve. Obviously.
They often do cement a lot of copper out first before they dissolve but I have the time to wait.

 

[coincard]

Thanks everyone for the info, I guess for now I am going to try putting a sample of the whole connector in AP and see what happens, next I will try the whole pins withe solder on the ends in acid cell and see what happens, keep you all up dated....

 

[Daniel0007a]

Well, it really depends on what the pins are coated with. If you have Aqua Regas then you can dissolve the gold from the copper. Streep said something about using Sulfuric acid conc 98% to react with any Lead if there is any. If there is lead but I am not sure it could drop the lead out allowing you to refine the gold. Whatever you do, don't use HCl/H202 especially if the H202 is higher 30% with sulfuric acid an dangerous chemical potentially explosive prana solution H2SO5 forms.

 

[coincard]

Well, it really depends on what the pins are coated with. If you have Aqua Regas then you can dissolve the gold from the copper. Streep said something about using Sulfuric acid conc 98% to react with any Lead if there is any. If there is lead but I am not sure it could drop the lead out allowing you to refine the gold. Whatever you do, don't use HCl/H202 especially if the H202 is higher 30% with sulfuric acid an dangerous chemical potentially explosive prana solution H2SO5 forms.

The lead I am not that concerned about as the acid cell has lead as one of the leads in the acid, it would be the tin that might be an issue that has me worried, but I am going to try several methods and see what works best, I will not mix sulfuric with anything that it should not be mixed with... Thanks for your reply...

 

[Yggdrasil]

Well, it really depends on what the pins are coated with. If you have Aqua Regas then you can dissolve the gold from the copper. Streep said something about using Sulfuric acid conc 98% to react with any Lead if there is any. If there is lead but I am not sure it could drop the lead out allowing you to refine the gold. Whatever you do, don't use HCl/H202 especially if the H202 is higher 30% with sulfuric acid an dangerous chemical potentially explosive prana solution H2SO5 forms.

This is plain wrong.
You can not dissolve Gold from Copper or other Base Metals all goes into solution. The Gold and Copper goes into solution and the Gold cements back on the copper until ALL ,metals are dissolved.

Who is Streep? Meryl?

You can use a reverse plating/stripping cell with 90-98% H2SO4 which will create Persulfuric acid on the border of the (Gold Anode?) can't remember now.
But as the Gold moves a short distance the Persulfuric acid goes back to Sulfuric acid and drops the Gold.

Pirahna Solution has NO use in reclaiming or refining of Gold.

Daniel, get your names correct please.
This is chemistry where one letter/number might be the difference between success, chaos or worse.

Piranha solution Sulfuric acid and Hydrogen Peroxide.
Aqua Regia HCl and Nitric acid.

Of these, only Aqua Regia has a function in Gold Refining.

 

[BlackLabel]

Who is Streep? Meryl?

Streep said "If there is lead."

I'm sure, Daniel is referring to a well known quotation from the movie "Kevin - Gold at Home"
"…to precipitate out any lead that maybe present.“