# Best way to remove gold plate from aluminum ?



## NobleMetalWorks (Mar 30, 2012)

I have several aluminum plates that are gold plated both sides, the entire plate of quarter inch block is gold plate. It looks like this:







I put a quarter on this for reference so you can see how much aluminum material I am dealing with.

I thought maybe if I scored the surface, like hard drive plates, and put it in HCL until just the gold foil is left over, but that is a lot of aluminum to react, I am worried about whatever the reaction will cause, heat, NOx, etc. But I have no idea how it will react in an HHO cell either.

Any advice or help would be really appreciated.

And yes, the gold tests positive.

And I am assuming the material under is aluminum because it doesn't react with a magnet, but is very very light but I am not sure.


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## Geo (Mar 30, 2012)

a sulfuric stripping cell will work fine, but your original idea would work as well. score the plates in several places and place in a diluted hcl bath. this needs to be a heat resistant glass or porcelain container as the reaction will create alot of heat. the gas that will be emitted will be hydrogen.if there is no reaction then the plates could be titanium, in which case a cell will be needed.


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## NobleMetalWorks (Mar 30, 2012)

Geo said:


> a sulfuric stripping cell will work fine, but your original idea would work as well. score the plates in several places and place in a diluted hcl bath. this needs to be a heat resistant glass or porcelain container as the reaction will create alot of heat. the gas that will be emitted will be hydrogen.if there is no reaction then the plates could be titanium, in which case a cell will be needed.




I think I will do it in a cell, I have a small one, I'll just cut the piece into two parts and process one after the other until the solution is totally exhausted. I don't like the idea of sticking a big piece of aluminum in HCl without knowing just how hot it will get, or how violent the reaction is going to be. I think I would rather test a small amount of just aluminum, without any gold, to see what the expected reaction might be, but still, the cell just seems like a much better way of doing it.

Thank you so much for the pointers!


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## samuel-a (Mar 31, 2012)

SBrown said:


> I think I will do it in a cell



You are in for a surprise then... Al and sulfuric acid REALLY react (remember you are energizing it with an outside source).
If it's Aluminum it would react with HCl and give off H2 gas and de-plate the gold foil.
Also, You can de-plate the gold form the Al in a bath of 1 mol NaOH, again, all you get is H2 gas.
See here: http://www.youtube.com/watch?v=QQq5XhTH46E It's practically the same idea.


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## NobleMetalWorks (Mar 31, 2012)

samuel-a said:


> SBrown said:
> 
> 
> > I think I will do it in a cell
> ...



Thank you for the information, and the link to the video. That seems like the best way to do it, I have avoided buying this type of scrap, now that I know this trick I'll be looking fo rit. I do have NaOH, so when I get my work area, and hood off the floor and on a cabinet, I'll try this next. I think it's 14K gold plate, at least that's what it looks like it tests at, so after I de-foil the gold plate from the Al, I will wash and dry, then process with HCl for other base metals since the foil will be thin, it should react with some I would think. Then process in AR for purity, anything I am missing?

Thanks again, I was so impressed with the video I almost ran outside and tried it. I really appreciate all the help this forum has offered.


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