# Gold on Motherboard



## Anonymous (Jun 15, 2007)

I'm just starting and have a question. Is this gold on the mother?


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## lazersteve (Jun 15, 2007)

Rick,

Sorry to let you know, but the yellow color is a surface lamination called a solder mask. Take a sharp knife or razor an scrape away a portion of the mask, you'll see the copper traces underneath and the laminate as a debris.

I scraped one with my pocket knife to show you what to expect:







Steve


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## Anonymous (Jun 15, 2007)

Thanks Steve. Yes I see that.


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## Anonymous (Jun 17, 2007)

Steve can you tell me are they worth it and is there an easy way to remove these pin plugs from the motherboard?

Thanks for all your great advise in this forum.

Rick


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## catfish (Jun 17, 2007)

Hi Rick:

I was looking at your post in where you ask if it was worth taking off the header plugs off of mother boards. That depends on each one’s situation. I just finished taking the header pins off of 11 mother boards this afternoon. You can wind up with quite a few header pins of the plug type and the individual jumper pins type. It took me about 30 to 40 minutes to do this.

Most IDE plugs have 39 to 40 pins each. Some plugs have 34 pins. The individual jumper pins can vary from 4 to 30 in a set.

I did a quick calculation on the approximate amount of gold in a 40 pin header IDE plug.

The pins measure .01 in wide, .01 in thick and .32 in of gold plated surface. This comes out to .0128 sq in per pin. 40 pins X .0128 sq in. = .512 sq inches of gold plated surface per plug. Most of the pins will have any where from 30 micro inches to 60 micro inches of gold plating.

The formula for figuring out the price of gold per plug is .654 X .512 X .30 = .10 cents per plug. If the mother boards are vintage type, (the picture of the one you have appears to be a vintage board) and they certainly have more gold than the later boards, they could have upwards to about 60 to 100 micro inches of gold plating. This would make each plug worth about .20 to .30 cents per plug, in gold value. Obviously, this is after you refine it and melt it into 24 K. These numbers are approximate but will be very close.

I take my plugs and pins off with a heavy duty heat gun. It only takes a couple of minutes to melt the solder and they fall out. Be sure and don’t overlook the two green epoxy chips on the mother boards, they have gold inside them.

Lots of luck

Catfish


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## lazersteve (Jun 17, 2007)

Rick,

If you have enough of them they are worth it. The older the motherboard the better the plating thickness.

Here is a list of several ways you can harvest these headers:


 Use a heat gun to melt the solder and pull the headers off, pins and plastic, all at once. Process the whole header using the Acid Peroxide Method.

 Chisel the header off using a sharp chisel and hammer or an air chisel.
Process the whole header using the Acid Peroxide Method.

 Clip the plastic away, then clip the pins off the board one by one. Process the pins in dilute nitric acid, AR, or HCl in the crockpot.

 Saw/Cut the board around the base of the header plastic. Be sure you don't get any of the SMD's (surface mounted devices) with the headers. Process the whole header, board and all, using the Acid Peroxide Method.

Steve


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## jerrycranium (Sep 12, 2007)

Steve,

I read in Recovery and Refining of Precious Metals by C.W.Ammen that the solder will cause problems in your refining.

When you melt the pins off the board they have solder on them, but melting them off is the most efficient way i have used.

Do you or anyone treat the pins with solder on them wih something to remove it first or is ths somthing that is not needed to worry about?

Thanks,

Jerry


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## lazersteve (Sep 12, 2007)

Jerry,

I have not had any problems with recovery from soldered pins using AP. Alternately, If you use straight HCl in a crockpot to dissolve away the base metals you should not have any problems either. Most solders contain tin which can cause problems when dissolved directly with nitric acid.

Steve


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## Flashman (Sep 12, 2007)

Ah, I was wondering how to dispose of solder. HCl you say, conc? or does a muriatic solution do it.

BTW, that top layer on circuit boards, any way to dissolve that. Got some PCI cards that look a bit like they're 100% plated over the traces. Since all pads and test points show gold.


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## lazersteve (Sep 12, 2007)

Flash,

I want to clarify my previous general statements about dissolving solders:

There are many alloys of solder and they all do not behave the same. I always test small samples of my ideas before I move to larger scale reactions. If you want to test a particular solution on a solder do a small sample first and verify which method works best for you.

I've seen some solders that will dissolve completely while others dissolve and leave silver chloride behind.

It all depends on the method of dissolving and the solder alloy.

As for your question about the solder masks, that was covered quite some time ago here:

Removing Solder Masks Topic

Removing Solder Masks Topic2

Read from this post on down and you'll get some good info.

Steve


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## macfixer01 (Sep 12, 2007)

Hi Steve,
Maybe it's just because I'm using a Mac browser (Safari), but I can't seem to get the Removing Solder Masks Topic link to work. I click it and it just opens a new window displaying the top forum level. I've found a few links to topics here inside other posts which similarly just take me to the top forum level. Since I'm guessing they're not all moved or deleted, I'm wondering if it's a browser problem? As a work-around, can you tell me what the path is to that thread? i.e. What section it's in (Help? Techniques?), and also the thread name if it's not obvious.

Thank you,
macfixer01


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## lazersteve (Sep 12, 2007)

Mac,

It works fine for me. 

What address is in you browser window before and after you click the link?

Some of the links behave oddly if the destination address varies with respect to the domain portion of the address, sometimes the link will fail to take you to the destination. 

To fix this unusal behavior just login to the forum from http://goldrefiningforum.com/phpBB3/login.php and navigate to the link. I think that ultimately the problem stems from a redirection page that is not redirecting for both the www and non-www versions of the site. 

I tried it from both address (which should be the same) and it works, but I have had problems when the address bar domain reads srv1.maia.com.

I really don't know why this is. I've added a second link in the post with the other target domain, let me know if either works.

Steve


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## macfixer01 (Sep 13, 2007)

Hi Steve,
Thank you for your reply. As I was reading your reply the URL in the window is:

http://goldrefiningforum.com/phpBB3/viewtopic.php?t=586&highlight=

And after I click the original link and end up at the top level, the URL reads:

http://goldrefiningforum.com/phpBB3/index.php

The new link you posted works fine! I never dreamed that solder mask could be removed with just lye and salt. I was sure it was going to take some combination of nasty organic solvents.

Thanks again,
macfixer01


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## lazersteve (Sep 13, 2007)

Mac,

The only difference in the two links is the leading www.

Steve


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