# Gold hidden under paint



## Romix (Sep 1, 2014)

Many boards have gold hidden underneath the paint. 
Any ideas of how to remove paint? 
My idea is to remove solder first,then remove base and finally AR. Would it work that way?


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## rickbb (Sep 1, 2014)

Many posts on the subject, use the search function.


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## Claudie (Sep 1, 2014)

Why would someone paint a board? Are you referring to the solder mask, the (usually) green coating? If so, try reading this post: http://goldrefiningforum.com/~goldrefi/phpBB3/viewtopic.php?f=49&t=4831
If you are actually talking about painted boards, maybe try some paint remover. :|


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## Anonymous (Sep 1, 2014)

rickbb said:


> Many posts on the subject, use the search function.



Have you turned into the forum police lately Rick? Chill out and stop being so harsh on people eh? It's really not needed. The next time you ask a question you'll get all offended when someone suggests you use the search function. You know you will.


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## Romix (Sep 1, 2014)

Claudie said:


> Why would someone paint a board? Are you referring to the solder mask, the (usually) green coating? If so, try reading this post: http://goldrefiningforum.com/~goldrefi/phpBB3/viewtopic.php?f=49&t=4831
> If you are actually talking about painted boards, maybe try some paint remover. :|



Yes green coating, that what I talking about, thanks for link.


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## Claudie (Sep 1, 2014)

For solder mask removal, this link is probably more help to you than the previous one I posted: http://goldrefiningforum.com/~goldrefi/phpBB3/viewtopic.php?f=52&t=6665

Here is a link to a better search engine to use when searching the forum: http://goldrecovery.us/forum_search.asp


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## Romix (Sep 1, 2014)

Claudie said:


> For solder mask removal, this link is probably more help to you than the previous one I posted: http://goldrefiningforum.com/~goldrefi/phpBB3/viewtopic.php?f=52&t=6665
> 
> Here is a link to a better search engine to use when searching the forum: http://goldrecovery.us/forum_search.asp



Thanks.

I cant find a video.


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## Claudie (Sep 1, 2014)

Just to make sure the video is still there, I went there to view it. It plays fine for me.
Here is a link to the video: http://www.goldrecovery.us/goldrecovery/videos/ShowVideo.aspx?id=soldermask&yt=0
You have to log in and click "Agree" the go to the videos.


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## Romix (Sep 1, 2014)

website asking me to download a plugin, that's very big risk of getting hacked. :mrgreen:


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## Claudie (Sep 1, 2014)

Well, I tried, the rest is up to you. :|


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## jason_recliner (Sep 1, 2014)

I can't see the video either. It seems to stick on "buffering...".

I had some success with sodium hydroxide thanks to a search on this forum. [Edit: I think Claudie's first link might even be the one I found.]
I put a PCB into a plastic take-away-meal style tray that was the perfect size, sprinkled some NaOH granules over the board and added just enough water to cover. In other words, as concentrated as possible.

It gets really quite hot. A glass beaker or corningware may be a better choice but I don't have either yet.
Do not let this stuff on your hands unless you want an interior view of them. It will burn skin and keep burning. Wear safety gear and don't let it splash.

Twenty minutes later, it had cooled and I diluted it a little and tipped it down a bathroom sink which was wanting of it anyway. Rinse the board under cold water and the mask comes off with a bit of a scrub. If I'd left it longer it might have come off even easier.


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## Smack (Sep 1, 2014)

spaceships said:


> rickbb said:
> 
> 
> > Many posts on the subject, use the search function.
> ...



Really? If your going to jump on Rick for that post you've got some catching up to do, there have been many like it. Maybe both of you could have bit your tongue/fingers and left the replies up to someone more helpful.


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## rickbb (Sep 2, 2014)

spaceships said:


> rickbb said:
> 
> 
> > Many posts on the subject, use the search function.
> ...



Nope, and didn't realize it would seem to be "so harsh". Not my intent and I have been told several times to use the search function when I've asked questions. Was not the slightest offended about it. Getting pointed it the right direction so I can learn is more important than just answering the question asked. Most of the time when I ask a question it's more of a where can I find the info than give me the info.


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## Harold_V (Sep 3, 2014)

rickbb said:


> spaceships said:
> 
> 
> > rickbb said:
> ...


For starters, spaceships needs to leave the moderating duties to the moderators. I take exception to anyone who places themselves in that position. You should not have been reprimanded for your comments. 

The advice to search the forum is sanctioned by me, and I expect by all moderators. We've been trying to get readers to do that for a long time now, and there should be NO exceptions. If a person needs help in searching by the proper terms, that I understand, but to ask questions that have been answered numerous times is NOT ACCEPTABLE, and it's not going to become acceptable. 

When new readers ask questions that display the fact that they have done little to nothing to help themselves, that's exactly the type of response we expect they should receive. We WANT them to search the forum. If they don't have enough time, or they don't have enough interest to learn properly, we don't want to be responsible for helping them in any way. That's not what we're here for. Our motto is refiners helping refiners, not refiners helping morons. We want to encourage every reader to read Hoke's book (to learn the basics, and get a clue about the terms we use on this board), and then to study that which has already been posted time and again. Posting the same information repeatedly is just making this board more and more difficult to use. 

I'm not going to be so kind to the next person who assumes he's a moderator. He may just find himself on the outside looking in. I do not expect readers, here, to correct other readers. If any of you have an issue with a reader, report it to one of the moderators and allow them to deal with the problem. In this case, it turns out the problem is really the person who is outspoken. He should have kept his opinion to himself, as it goes against board policy. I don't look upon that kindly. Knock it off, spaceships. 

Harold

edit


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## necromancer (Nov 27, 2014)

jason_recliner said:


> corningware may be a better choice but I don't have either yet.



i find pyroceram corningware in donation stores, i have about 20 different square pots + 1 very nice 750ml round pot with a handle
i can buy them with lids for 4 to 6 dollars, much better price then buying new ($70.00 for 4 pc set = 2 square pots + 2 lids)
you also may want to try freecycle.org, choose your town or city & keep your eyes open or just ask.


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## MarcoP (Nov 27, 2014)

Pyroceramic is P market, if that is correct where I live is near impossible to find them, would I be able to do the same things with Pyrex too?


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## Geo (Nov 27, 2014)

MarcoP said:


> Pyroceramic is P market, if that is correct where I live is near impossible to find them, would I be able to do the same things with Pyrex too?



Never use pyrex on an open burner or electric burner unless it is made for it. Visions cookware by corning or the corning Pyroceram bakeware is recommended for direct heating.


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## necromancer (Nov 27, 2014)

yes, but the corningware is a good choice due to its indestructibility & heat resistance.
you can heat them up red hot & put them on a cool metal shelf without them exploding due to the temperature difference.

i have treated mine very badly and they stay intact, the tops are not as durable but do make a good cover to keep in the fumes.

if you like i would be willing to ship one out to you at no extra cost if you pay the shipping & face value of the corningware.

pm me if that is worth your while. there is always a cheap slow cooker with ceramic insert if you are not using it for hot nitric baths or incinerating.

i have also made a post with a link to corningware product numbers & information


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## necromancer (Nov 27, 2014)

this is a power supply board, it's a 1/16th inch sheet of copper alloy. other then the gold connectors there is layers of gold under the solder mask

i put arrows in the photo showing where the gold is under the solder mask

gold coating is between the arrows.

i will end up putting this board on a hot sand bed to remove the components then remove the solder mask to expose the gold.
not sure how i will remove the gold yet, maybe the A/P method due to the large amount of copper on the board.


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## MarcoP (Nov 28, 2014)

Thank you Geo I will surely keep that in mind when choosing.

However I had very hardly obtained P marked corning ware and I managed to crack it within few days. I did place a 1/3 full beaker inside the empty corningware and then put on top of my electric burner, I did wanted to evaporate the solution down so I went to 80°C (temp inside the beaker) but after quite few minutes the, supposedly pyroceramic, broke. I would image it did happen because the cornigware was empty, silly me, and by putting water (under the main liquor level) everything would have gone ok.

Hey necromancer, thank you very much for your offer. I'll keep looking while keeping your offer in mind. Really, really appreciated.
I believe there is an issue with the arrows in your photos as none of them are pointing to gold plated areas. I normally scratch the solder mask with a steel blade to really see if the underneath plating propagate all over the surface area or it's just few dots here and there.


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## kurtak (Nov 28, 2014)

jason_recliner said:


> It gets really quite hot. A glass beaker or corningware may be a better choice but I don't have either yet.



NaOH is corrosive to glass - it will etch beakers & corning ware - better to use plastic bucket, cast iron pot or stainless pot

here is a picture of a beaker that has been etched by NaOH :arrow: http://goldrefiningforum.com/phpBB3/viewtopic.php?f=47&t=21342&p=220281&hilit=etch+glass#p220316

Edit; Do NOT use NaOH in an aluminum pot :!: 

Kurt


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## necromancer (Nov 28, 2014)

MarcoP said:


> Thank you Geo I will surely keep that in mind when choosing.
> 
> However I had very hardly obtained P marked corning ware and I managed to crack it within few days. I did place a 1/3 full beaker inside the empty corningware and then put on top of my electric burner, I did wanted to evaporate the solution down so I went to 80°C (temp inside the beaker) but after quite few minutes the, supposedly pyroceramic, broke. I would image it did happen because the cornigware was empty, silly me, and by putting water (under the main liquor level) everything would have gone ok.
> 
> ...




you can see the scratched area in the middle of the photo. its a nicely plated area. i will photo after removing the mask


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## MarcoP (Nov 28, 2014)

I see it now, thanks.
Last time I've used 30% lye (20% wasn't enough in my circumstances) to remove the solder mask, the gold plating tarnished. Not sure what happen there but I don't believe I lost any.


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## Anonymous (Nov 28, 2014)

Tarnished Marco? In what way?


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## MarcoP (Nov 28, 2014)

I should have taken a picture! It only happened on wide plating areas find in LCD boards or what I believed to be a very thin plating not used in contact points. If I properly recall the plating darkened to a dark brown color. May the term I've used, tarnished, isn't the proper one but it was like it was cooked, or burned, by the lye.

I was still able to recover 1.3gr of double refined gold powder out of 150 ram sticks and many other boards with tarnished plated area due the lye treatment. Maybe I cooked them for too long when instead a couple of minutes were sufficient. However I still believe was just a visual effect without any loss. Hope I'm right here.

I didn't post my issue, even if singular, because next time I wanted to try boiling them for a couple of minutes as instructed without exaggerating.


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## GotTheBug (Feb 13, 2015)

I just noticed the same thing, and am believing some gold was removed by the naoh and h2o2 mix. If so, how can I recover gold from NaOH solution?


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## Barren Realms 007 (Feb 13, 2015)

GotTheBug said:


> I just noticed the same thing, and am believing some gold was removed by the naoh and h2o2 mix. If so, how can I recover gold from NaOH solution?



If it will not settle to the bottom of your container dilute the solution and it should settle to the bottom then you can remove the solution and clean the foils of the rest or the residue of the solution.


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## Beirdo (Feb 13, 2015)

One note to be careful about: on most circuit boards that I've seen, what is under the soldermask is copper. Typically, the gold plating is applied *after* the solder mask. There are, of course, some exceptions, but I would not be expecting to find much gold buried under solder mask in most circuit boards. Gold is usually plated onto things that are connectors primarily, and other than a few RF circuits, there is little advantage to having a gold surface, especially if it isn't exposed. The gold is there to keep the connector's contacts from corroding, basically.


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## MarcoP (Feb 13, 2015)

GotTheBug said:


> I just noticed the same thing, and am believing some gold was removed by the naoh and h2o2 mix. If so, how can I recover gold from NaOH solution?


I didn't use any H2O2, but if you have a touch stone you could easily test if gold was removed or just darkened by the lye. By next time I will probably have a touch stone with all testing solutions, day after day I see how easy certain things could be with one.


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## GotTheBug (Feb 13, 2015)

I had a few boards, cell phone and old sound blaster (which was nice since it was full plate on both sides), and thought it was a good idea to "hurry things up" by adding h2o2. I still have the solution, so will dilute it and play a bit just to see if any went into solution. I've already run the slime in AR after rinsing well and nothing there, so we will see. Of course, it is also possible that the plating was simply discolored by the lye. This was my first go with hot lye, since I was basically scared. All went very well, and no permanent badges for my efforts!

Now is where I take another moment to thank you guys, again....

Paul.


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## jason_recliner (Feb 13, 2015)

kurtak said:


> jason_recliner said:
> 
> 
> > It gets really quite hot. A glass beaker or corningware may be a better choice but I don't have either yet.
> ...


Good to know. Thank you for the correction Kurt.


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## patnor1011 (Feb 14, 2015)

For me personally amount of gold to be recovered from odd soundblaster or RAM stick does not warrant dangers involved when working with hot NaOH. No matter how many of soundblaster cards I will have, it will take the same amount of danger be it one or 20. 
I stopped chasing cents, I was many times losing dollars in the process. I will leave that minuscule amount of gold to copper smelter to recover. You may get much more for depopulated board with solder mask on (depend on where you are located) than gold recovered from this minus supplies and time involved.


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