sad said:
trashmaster said:
Hello all ,,, Try scraping back some of the green mask ,, some of the electronic boards with the light green mask will be GOLD plated underneith the mask,,,., I get around 50-100 of these plantronics boards per year..,I have only been collecting them as for now... THIS FORUM IS GREAT ,, . thanks to everyone that post here and to LAZERSTEVE Many thanks..
What is the the best way for scraping the green mask?
I'm wondering if you have heard of a solution that strips the boards of the solder protective covering, revealing the plated copper/gold etching on the boards. The trick though is to get rid of the parts--IC's, resistors etc.
It's a pretty time consuming job.
Some heat their boards with a heat gun, to melt the solder, then scrape the components off---then treat the boards in the solution to remove the solder cover. Then peel or scrape the etching --or cut the boards and do a nitric/distilled water removal. Like you would for fingers flares or card edge fingers.
If you have boards that are solder free try this.
You'll need a thick plastic tub.
Mix 1 pound Sodium Hydroxide---slowly because it can heat up real fast and boil over-- and 40 ounces distilled water. Let it cool. Add a small spoon of table salt and pour it into your thick plastic tub.
Drop a couple of boards in and let them set for maybe 3 or 4 hours--hang them to dry. I use paper clips and hang them on fishing line. You'll see a white powdery residue on the surface. Then you take a scrub brush to remove the solder mask. It may take more than one treatment. But your gold/copper etching will be free to work with---peeling it off or cutting the boards into smaller pieces. This is recommended for boards with little or no solder.
I just started batch of AgAuPtRh's solution for stripping the solder mask from page three on this thread.
It's working great!
I made a few slight changes though. Instead of hanging to dry, once the mask loosened on the boards I just rubbed them with an old toothbrush and rinsed them off in the solution. The green solder mask washed right off. I then stood them up in a plastic strainer to dry and let any solution drip into a glass dish so I can pour it back in the bin I'm soaking the boards in. I'm know I'll have to wash the boards off later before I proccess them but I'm not to that point yet.
I also doubled the amount of solution I made when I saw how good it was working so I can soak more boards. That way while I'm cleaning some boards others are soaking so I'm not just waiting around for a few boards to get ready.
Make sure you wear your gloves and cover yourself, you don't want any lye on your skin or in your eyes.
Steve
even for a small board. Personally, I like to use an Exacto knife - there are many types available but I prefer to standard sharp tip blade. You could also use a razor blade knife. I just start by very carefully scraping a small area until the layer underneath starts to show. Something else to look for is the the grounding holes and the holes for more electronic parts in the PCB(circuit board). If they show a gold color then chances are good that the board is gold plated. 
