# how much gold foils



## timmyhartsing (Jul 4, 2013)

hi there forum members,i have been saving foils for a while been peeling them from boards with a exact o knife. i know its a long process but i can usually strip a board in about 10 seconds and it saves on acid in the long run .i am wondering how many grams of stripped off foils does it take to get a gram of pure gold ? i know it will depend on the process i use but just wondering


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## mls26cwru (Jul 4, 2013)

timmyhartsing said:


> hi there forum members,i have been saving foils for a while been peeling them from boards with a exact o knife. i know its a long process but i can usually strip a board in about 10 seconds and it saves on acid in the long run .i am wondering how many grams of stripped off foils does it take to get a gram of pure gold ? i know it will depend on the process i use but just wondering



this is not meant to be mean, but rather to try to help... peeling the foils off is a waste of time and not so much a waste of acid. the foils you see are actually a 3 layered stack of metals, (not just gold, so you cannot go right to the refining step) the majority of which is a copper base layer, a thin nickle middle layer, and the gold top layer. if you use the copper 2 chloride method (Acid/peroxide; AP method) the etchent attacks the copper and nickle and not the fiber board. the fiber board will just sit in the acid and not react at all, so there is really no reason to mechanically separate the two. 

It could possible save time though. I find that it takes roughly a week in the Copper 2 chloride solution for all the foils to disslodge with occasional aggitation. I would imagine it would only take fraction of the time if the foils are separated... so that part is up to you.

and to answer the question about how many foils you need... I find that from roughly 1lb of clean gold fingers (still on the board) I can usually get around 1.9 grams of gold.

Mike


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## AndyWilliams (Jul 4, 2013)

timmyhartsing said:


> hi there forum members,i have been saving foils for a while been peeling them from boards with a exact o knife. i know its a long process but i can usually strip a board in about 10 seconds and it saves on acid in the long run .i am wondering how many grams of stripped off foils does it take to get a gram of pure gold ? i know it will depend on the process i use but just wondering



I'm going to guess and say that it takes less than 227 grams! :lol:


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## CBentre (Jul 4, 2013)

Your answer is in front of you now it's up to you to do the math. From the previous answers we can see that from a lb of clean cut fingered boards you get 1.9g of refined gold. Some say up to 2.25 but we will use 2 to simplify things. Theoretically if you get 2g from 1 lb then you should be able to strip a 1/2 lb of clean cut fingered boards to produce 1 gram of refined gold. Keep in mind it takes roughly 40lbs off pci/ full boards to produce 1 lb of clean cut fingered boards so if you take 20 lbs of boards you may be able to produce the quantity for your experiment. Post your results when you get them and we will have your answer. 

Steve


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## Geo (Jul 5, 2013)

timmyhartsing, you are wasting your time pulling the foils off the board. cut the fingers close and process the cut fingers. saying it saves on acid is false. the acid does not react to the board. the amount of acid would be the exact same if you pulled the foils or left them on the board.the best way to calculate a yield is by weighing clean, close cut fingers before processing. keep in mind that if you picked several members at random and provided the exact same material, they will achieve different results in weight from one another.


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## goldsilverpro (Jul 5, 2013)

Since most people here don't sit around peeling fingers with an x-acto knife, there isn't much data on the percentage of gold in the foils. It is easy to get a rough idea, though, by calculation.

As far as I know, the copper is most always applied to the board material as a foil that either weighs 1 oz (28.4g) or 2 oz (56.8g) per square foot. The 1oz would weigh .197 g/in2 and the 2oz weighs .394 g/in2.

Assuming the Ni is a fairly typical 100 microinches thick, it would weigh about .015 g/in2. Assuming the finger gold is a typical 30 microinches thick, it would weigh .0095 g/in2.

Putting this all together, the gold percentage of the peeled foils would be either 4.3% or 2.3%, depending whether the copper is 1 oz or 2 oz. A square foot of fingers (that's a lot of individual fingers!) would contain about $53 in gold.

There is also probably some adhesive on the back of the copper that wasn't considered.

Doesn't seem to me like it's very productive to sit there and peel them.

Note: I originally made an error in the calculations which has since been corrected and edited.


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## Geo (Jul 5, 2013)

Chris, i wish i had your analytical type mind. i deal more with cause and effect.


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## goldsilverpro (Jul 5, 2013)

Geo said:


> Chris, i wish i had your analytical type mind. i deal more with cause and effect.



Thanks. My main thing is also cause and effect. I do the math because I enjoy it and it gives me a mental picture of values. Also, the math has sometimes made me a lot of money.


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## timmyhartsing (Jul 8, 2013)

thanks for the great info ,i will take your advice and just trim the fingers close and treat them with a copper 2 chloride method, it is going to save a lot work in the long run.thanks everyone.


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## CBentre (Jul 8, 2013)

There you go, now your thinking. Good luck with the new en-devours.


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