# What electronic scrap would be pure gold?



## Paige (May 28, 2007)

Listed @ eBay 260 123 107 482 are some "solid" gold pins. I was wondering what kind ofpins they were and aren't they more likely gold plated brass?

The guy doesn't say he used any nethod such as acid to determine they are pure other than to brak one if half to shwo a yellow metal through out.

Paige


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## toadiesop (May 28, 2007)

Don't fall for it. I'm guessing copper/nickel in the middle.

How do you find the auction with that number you gave? And I sell ebay all the time... I don't know that..??? 

edit****

Heh... take the spaces out... :roll:

Hmm, I don't know now that I see it. Could be brass. I'd ask how many it takes to make an ounce and how big they are. Then you'd know.

edit again***

I know that material that the bag in on. It's used in kitchens to place glasses on to dry so I can tell the approximate size of those items.

If they are "pure gold" I'd say it would only take 1-2-maybe 3 to equal and ounce.


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## Paige (May 28, 2007)

It's just easier to read if you break it down into sets of 3 numbers.

Paige


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## goldsilverpro (May 28, 2007)

In 40 years, I have never seen solid gold connector pins. Technically, there would be zero benefit in making them solid gold. Electronic manufacturers are not stupid and they don't waste money.

Many connector pins are gold plated brass or some other yellow copper alloy. When you break a piece a gold plated brass, the part is yellow all the way through. This leads people to believe that the part is solid gold. Like you said, the seller didn't mention acid testing them.

I would guess that the seller is either stupid or a con man. I suppose that there is some faint possibility that these are some oddball experimental parts or super critical parts that are solid gold. My guess is that the odds against this are probably more than a million to one. Certainly not worth taking a chance.

Let's go way out on a limb and assume they are solid gold. What karat are they? - 6, 10, 14, 18, 24? The guy has a "buy now" price of $220/ounce. If they are solid gold, the guy could get close to spot for them somewhere else. Why take a chance on an eBay auction.

Although the one he cut looks nice and yellow, that means nothing. His weight is one avoirdupois ounce. His not using troy is a clue that he doesn't know precious metals.

I would never, never take a chance and bid on these but, just for kicks, I would ask the seller if he nitric acid tested them. I would also ask him if he has any documentation on them.

There's no such thing as a free lunch.


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## fixinator (May 28, 2007)

On the oldest computer I ever dismantled it had connectors that has solid gold tips attached to a base metal pin. Only the very end where it made contact was gold. More often than not the gold is just plating that is very thin and sometimes so much so that it is translucent.

Fix


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## catfish (May 28, 2007)

Hi Paige and all:

I have looked at the alleged pure gold pins that you have referred to (260123107482). They are not pure gold. For many reasons.

The Federal Trade Commission, Code of Federal Regulations, Title 16, Commercial practices part 23 January 1999, for precious metals under F.T.C. regulations for plating thickness for decorative gold has three (4) different classifications for the thickness pf plated gold.

Gold Flash (10k) .000007 inches or .174 microns

Gold Electroplate .000007 inches or .175 microns

Gold plate .000020 inches or .50 microns

Heavy gold plate .000100 inches or 2.5 microns.

The American Society of Testing and Material (ASTM) have defined the following standards (B488-95) titled electroplated coatings of gold for engineering uses. This does not include Military specifications (Mil specs) these specifications are MIL-G 45204C.

Both these specifications define the purity, (type), hardness (grade, and thickness (class).

I will not go into the two classifications of purity or hardness. The purity is always 99.0 or better and hardness is not an issue.

ASTM standards:

Class Thickness

00 20 micro inches or .000020 or .005 microns

0 30 micro inches or .000030 or .762 microns

1 50 micro inches or .000050 or 1.25 microns

2 100 micro inches or .000100 or 2.54 microns

3 200 micro inches or .000200 or 5.06 microns

MIL-G-45204C Military Specifications:

Class Minimum thickness.

00 .00002

0 .00003

1 .00005

2 .00010

3 .00020

4 .00030

5 .00050

6	.00150

As you can see if these are industrial pins as he sez, then the most thickness would probably be would be .000200 micro inches. At .75 square inch of surface area and a thickness of the maximum of class 3, 200 micro-inches, the gold content would be .04825 grams per pin. If there are 100 pins, then the total gold would be 4.82 grams or $104.22.

My guess is that they are not class mil specs, but at best case they could be some where between 30 and 100 micro inches at best. ASTM Standards. Worst case scenario would be $15.63 or best case would be $52.10. for 100 pins.

You may want to email him and ask him to make a simple nitric test on 1 gram of pins in 10 ml of nitric acid. How long does it take to dissolve and is it fine particles or the whole pin flakes.

I would be ware of anyone saying they have pure gold. The only place you are apt to find pure gold is in Fort Knox and that is only 99.5 Ha-ha.

If you have any questions on how to determine the amount of gold in items, hit me on PM.

Catfish

The formula for gold content is 19.3 grams of gold = 1cc


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## goldsilverpro (May 30, 2007)

Fixinator,

Were these backplanes where the connectors had karat gold tips? In about 1983, when we had a mobile refinery, I assayed a lot of connectors from backplanes. 

There were 3 basic types:#1 - those with plating on the entire pin. #2 - those with plating only on the contact area. #3 - those with no plating but with a small 18K contact point. You almost needed a magnifier to see #3.

The gold price was about $450 at the time. #1 ran about $2/pound, #2 about $.75/pound, and #3 about $7/pound. These prices were for the whole connectors only, including the plastic.

Catfish,

You've done a lot of good work on these thicknesses, I see. You can't take these figures for gospel truth, however. The decorative FTC thicknesses are probably the most reliable, now days, since they are consumer goods and the thicknesses have to do with labeling and markings. The FTC numbers are minimums for specific labeling. The others are not so reliable unless, maybe, they are military parts. The Mil-Specs were originally used for the military, but a lot of electronic manufacturers starting using them also. In recent years, most manufacturers use the ASTM standards, I think. I don't think there's any law making electronic mfgrs. adhere to any of these. They are used a lot because they are easy to spell out. These Thickness Specs are more commonly used today than in the past. Even today, however, there are lots of parts that fall outside of the specs. Use them as a guide only.

There are two ways of plating. You can plate by voltage or you can plate by amperage. Much decorative plating (costume jewelry, e.g.) is plated by voltage. In other words, the plater sets the voltage (say, 3 volts) and starts plating. He examines the parts several times during the plating, to check for such things as color and brightness. When it is done to his satisfaction, he pulls the parts out. The thickness depends on the time in the tank plus lots of other variables. This type of plating is more of an art than a science and the thickness will vary a lot more.

All electronic parts are plated by amperage. The plater measures the surface area of the parts and from this he calculates the exact amperage for the load and the thickness desired determines the length of time the parts remain in the plating tank. Since it is the amperage that determines the total weight of gold deposited, per unit time, this type of plating is very scientific. However, the amount of time in the tank only gives the average thickness of the parts. Many parts are plated on racks. There may be 300 parts on a rack and the plating thickness on each part is dependent on the part's position on the rack. For example, the parts on the perimeter locations will plate thicker than those located in the center of the rack, since the perimeter is a higher current density area than the center. Also, on each individual part, the perimeter of the part, itself, will plate thicker than it's center - sometimes, 3 times thicker on the perimeter. Therefore, every part will vary, somewhat, both on it's overall average thickness and on the various areas of the particular part.

All in all, this says that, when assaying any type of plated parts, it is not reliable to test only one part. You have to either run several parts in one assay or several different assays.

I know this is confusing and I haven't explained it very well.


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## catfish (May 30, 2007)

Gold Silver Pro:

After reading your post on specifications for gold plating, I agree that in the past, like in the sixties through the late eighties the gold plating on consumer products were in some cases very heavy and exceeded the ASTM specs. I have since read that the ASTM specs were changed in 1999 to more accurately state the requirements for gold plating for engineering specs due to many manufactures were out sourcing the manufacture of their products and also to take into consideration the price of gold and also utilization of new technology in plating processes. Not to mention manufacturers becoming more profit margin oriented.

I agree that the specifications for consumer engineering products should only be used as a mere guideline to quickly determine the best/worst case scenario purchase price for consumer electronics gold plated items. Then one would certainly take into consideration the vintage of the items and the purpose they were intended to be used. If the items were manufactured prior to 1990, then one may want to use the Mil specs, but after that time frame the gold content has certainly went down. 

After your explanation of the possible variances of the quality of the gold content on different items due to the physical location on the plating racks, I also agree that it certainly would be difficult to get a good test on just one item. Maybe one could take a sample and test in accordance with statistical analysis sampling techniques, and come up with an average plus or minus some acceptable tolerance figure. 

I have purchased many different items off eBay and the only ones that I actually came out ahead, in cost versus output yield in gold are older military pins and plugs. I have broken even on older vintage computer equipment such as older CPU chips, fingers, and memory sticks. My advice to anyone who purchases off eBay is kind of like Las Vegas, you loose more often than you win.

I found your explanation of the actual process that the manufacturers use, to be very interesting and informative. I continue to learn something new every time I log on to this forum from you, Harold, Steve and the other members. Thanks for your many contributions. 

Catfish


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