# Gold plateing vs Gold flashing



## oldtimmer (May 5, 2009)

I had a friend drop off some gold plated cans that he wanted me to look and see if it was cost effective to recover the gold from. He had been told that they were gold plated. After playing with them for a few days, I believe that they are only gold flashed. He has access to several thousand of these and wants to work with me to recover the gold.

My question is at what thickness of gold flashing is needed on a steel can so that it looks like it has a good gold plateing? I have finished running 400 of these cans through a gold cell and finally melted down the gold today, and ended up with .85 grams. There is still a small amount of gold still in the acid cell as I just decanted the acid off as I needed to see what the amount of gold recovered so that I could get a quick estimate on the gold recovered.

I have used the formula that was posed before:
Example: The gold spot is $650. You have 9.58 square inches of gold plate that you estimate to be 30 micro" thick. $650 divided by 10000 X 9.58 X 30 = $18.68. 

Or in my case:
$900/10000X1400X.2=$25.20 $25.20/31=.86gram

The surface area is about 3.5 square inches.

By going backward on the formula, knowing the yield and surface area, I have caculated that from the gold that I recovered, that the thickness of the gold is about .2 micron thick. Does this seem correct, or is my caculation somehow in error?


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## goldsilverpro (May 5, 2009)

The difference in gold flash and gold plate is mainly thickness. Actually, they are both gold plate and can be done from the same gold plating solution. The thickness is just a matter of how long the part is left in the tank. 

Gold flash is mainly just for color and is usually from 5 micro" to 10 micro" thick. What is called gold plate provides protection for the part and usually runs from 12 to 65 micro" thick, although, for rare applications, it can be thicker.

A gold flash is usually used on cheap decorative items such as costume jewelry and stainless steel flatware. It is also used on electronic parts that require no wear protection. On e-parts, a gold flash will usually appear paler than gold plate, although you can't totally rely on appearance. 

Gold plating on pins and fingers and most anything else that can wear from multiple insertions runs about 30 micro" thick, although there are many exceptions.

The calculation you made is one decimal point off. Instead of $18.68, it is $1.87. I was the one that originally provided the formula you supposedly used. I'm afraid I created some confusion when I changed it a long time ago. When I first changed it, I used the factor of 10,000. When I discovered my error, I corrected it to be 100,000.

To set the record straight, here is the correct formula:
Gold plating value, in US dollars = (spot price of gold in US dollars/100,000) X (surface area of plating, in square inches) X (plating thickness in microinches). 

For the hypothetical data you gave, here is the equation:
(650/100,000) X (9.58 ) X (30) = $1.87

There is also other confusion. Don't use microns in the formula. Use microinches. One microinch (abbreviated micro") is one-millionth of an inch or 1/40 of a micron. In your case, .2 microns is 8 micro" (.2 X 40). This thickness would qualify as flash gold. 

Where did the 1400 come from?

If you're still confused, let me know.


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