# Preparing circuit boards for processing



## paulphil1 (Aug 25, 2012)

As i am compiling a large number of circuit boards, I was wondering if I need to remove all the compacitors and resistors, ect (even the very small ones)?

Thanks

Paul


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## butcher (Aug 25, 2012)

you do not process whole circuit boards, you cherry pick certain components which yield value, and these are processed separately, depending on what the component is can determine the process to choose.


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## galenrog (Aug 25, 2012)

I have begun depopulating select components for a few
days now. SMD caps and resistors, all ICs, cap types known to contain PMs, copper coils, and other componenets know to contain PMs. As I have been learning by lurking and reading Hoke, not all is as it seems. When in doubt about which components to harvest, go ahead, segregate them, do a little
research, then a test batch according to what you learn.

Have fun. Be safe.


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## paulphil1 (Aug 26, 2012)

Thanks all. I guess I should have said "do I need to remove all the components before I process the board for its gold plating" ?


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## butcher (Aug 26, 2012)

if the circuit boards copper traces are gold plated, then yes you should remove all of the components from the circuit board, remove the solder as much as possible, and remove the epoxy coating (solder mask).


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## kjt124 (Sep 6, 2012)

Is there an acceptable way to remove the solder mask from a gold plated board other than the laser etch, sanding, media blasting, and the commercial etchant? I would imagine I could concoct a chemical etchant at home, but I can't find very reliable data on what the mask is made of so I am not sure where to begin. I would certainly prefer to not use heat - I know how bad the vapor from those things is.

If I had to make a guess I would imagine it is an amine based epoxy which, if memory serves me, is very chemically resistant. Any help would be appreciated


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## pimpneightez (Sep 6, 2012)

Hot sodium hydroxide will remove solder mask. Warm it slowly to boiling, put in your boards, boil for 5 mins, remove and clean. Wash well with fresh water. Job done. Wear gloves, eye protection and avoid breathing the steam. Im under the impression if sodium hydroxide gets in your eye you will go blind.


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## kjt124 (Sep 6, 2012)

Thank you for the safety tips - they are always appreciated. I remember a small burn from hot potassium hydroxide i got years ago at work. It was unpleasant to say the least.

Your sodium hydroxide idea sounds like a wonderfully simple solution. I imagine I would be able to reuse the solution again and again until it went sludgy.

Thanks!


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## kjavanb123 (Apr 28, 2013)

Hi,

What is the ratio of sodium hydroxide and water? In above solution.

Thanks
Kevin


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## lazersteve (Apr 28, 2013)

The video has the weight of sodium hydroxide used in the mix:

Solder Mask Removal Thread

Steve


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## justme2 (Jan 21, 2014)

Been Reading and studding the forum for a while now and keep hearing about these videos but haven't been able to access them. If I have to pay for them ok, but most posts imply they are free. Don't watch many you tube vids as most are not realizable and many are just plain dangerous. thanks for the help.


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## bmgold2 (Jan 21, 2014)

justme2 said:


> Been Reading and studding the forum for a while now and keep hearing about these videos but haven't been able to access them. If I have to pay for them ok, but most posts imply they are free. Don't watch many you tube vids as most are not realizable and many are just plain dangerous. thanks for the help.



Here's the link to Lasersteve's website where you can find the videos. You have to log in but the username and password is right on the site. Just read and follow the directions on his site to access the videos.

http://goldrecovery.us/

I use Linux here instead of Windows and I have not figured out a way to view these videos but have seen most of them before when I did use Windows and they were good and free although I think you can also buy a DVD.


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## JoeyJoystick (Aug 29, 2020)

pimpneightez said:


> Hot sodium hydroxide will remove solder mask. Warm it slowly to boiling, put in your boards, boil for 5 mins, remove and clean. Wash well with fresh water. Job done. Wear gloves, eye protection and avoid breathing the steam. Im under the impression if sodium hydroxide gets in your eye you will go blind.


 Hi,

I can confirm this. A friend of mine was a truck driver some 35 years ago. He drove a tanker truck and when discharging he made a mistake and got a full load of NaOH straight in his face. Immediate medical attention made sure he got his sight back after 2 weeks. The doctors told him he was incredibly lucky. This was concentrated NaOH, but at room temperature.

And on a different note, I may here offer an alternative method to keep your drains clean without using NaOH. My drains used to block frequently and either I cleaned it with NaOH or my GF cleaned it if I was out of country. Not quite sure how she used to do this though, but I believe it involved long sticks... lol. Anyways, Back in those days my washing machine was outside (Sunny Thailand..) but the new one I decided to place inside. And surprise surprise, I never had to clean my drain again because of the washing powder cleaning up the drain. I am also using this now for the drain of my AC. I just put a few spoons of washing powder in the drip tray of the AC every few months. Works like a charm. And no more water dripping down in my room.

Joey


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## booneire (Jan 18, 2021)

hello
sorry I know this is an old thread. I'm having the same problems with videos and some images that members load up.
the below link to goldrecovery.us .it just says the link is not working and have been directed here to many times. is it because I'm trying access this site from Ireland.

I just want to say thanks to all members. I'm a registered member since december. there's a vast amout of knowledge on this exceptionally good web site. I'm slowly gathering stock. I'm reading Hokes boom and reading as much as I can from this website. thanks from Ireland.
david

Here's the link to Lasersteve's website where you can find the videos. You have to log in but the username and password is right on the site. Just read and follow the directions on his site to access the


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## FrugalRefiner (Jan 18, 2021)

The problem is not your location. Lazersteve's site has been down for quite some time. We don't know when he might get it back up again.

Dave


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