Question

[kole55]

hello.I posted a post with this material before. I removed the metal parts from the pins, I also cut off the caps from the transistor, but I couldn't remove all the metal caps, the hoop remained and some caps as seen in the picture. Now the question: put it in the AP.since I work in the field it has stood in the AP for two months without interference. the material looks as if all the gold has been removed from the material but it is not there. i guess there is a lot of ferric chloride in the solution that squeezed the copper out of the solution and “glued” it to my material. whether that is so or the material is bad. i did a lot of pins in the AP and so far it hasn't been like this. thanks in advance for every comment and experience.

 

[Martijn]

I once put pins with some more reactive metal (iron?) parts mixed in between in AP and it covered all surfaces with copper fast. Including fully plated pins.
I guess that was because of the electric contact between the plated pins.
It left behind iron chloride which dissolved the iron and later all the cemented copper and pins. Just give it some time.
I dont know if these caps are made of stainless steel and how that reacts to AP. I guess that's inert to AP.
Maybe test one cap in some nitric?
Martijn.

 

[kole55]

thank you for your reply. and I also assume that the iron in the solution cements the copper on the needles so that for now the gold is not visible. that time should be given to dissolve all the iron and change the solution with fresh AP.nitric acid does not work for caps. in fact i think nitric acid alone cannot dissolve iron without the addition of battery acid or HCl. so i use the AP method it takes time, it works slowly but i'm not in a hurry.i just wanted confirmation that the iron cements the copper from the solution to the pins so i don't see the gold.thanks again.

 

[g_axelsson]

I've seen that too. Iron goes into solution as copper is cemented to the pins.
I use old copper chloride solution on pins soldered to CPU:s, for example P4. In my case it eats the solder in just a few hours and the pins covered in copper can be scraped off. The gold is still under the copper and will be exposed after the iron is dissolved.



Göran

 

[kole55]

I've seen that too. Iron goes into solution as copper is cemented to the pins.
I use old copper chloride solution on pins soldered to CPU:s, for example P4. In my case it eats the solder in just a few hours and the pins covered in copper can be scraped off. The gold is still under the copper and will be exposed after the iron is dissolved.

DSC04431.jpg

Göran

thank you