# Gold Plated Aluminum Pins



## JWalker (Sep 30, 2013)

I have read and searched, and read. I have seen an equal number of quips stating that Aluminum in a Sulfuric Cell is no issue, and the same number referencing a reaction that is quite large and unsafe. 

Questions:
Can I put my aluminum pins and blocks in my Sulfuric Cell without a big dangerous mess? 

Would it be better scar/scratch them then soak them in HCL (possibly boil in HCL as some have commented) to dissolve the aluminum and liberate the gold plate from the aluminum instead?

Thanks


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## JWalker (Sep 30, 2013)

Sorry about the title. Should read: Gold Plated Aluminum Pins. and the "Blocks" i spoke of are 2" long, 1/4 tall, 1/4 wide and have between 20 and 30 1/16 wide holes drilled through them. Completely plated in gold.


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## gold4mike (Sep 30, 2013)

Can you post a pic?

Are you sure they're not just anodized aluminum?

I had some sprockets for my go kart that were anodized and appeared golden.


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## Pantherlikher (Sep 30, 2013)

Hello JWalker 

I see you just joined this month and have read...

What have you read? Any good books lately? A post here and there? A couple of Youtub will hurt you videos?

Please take a deep breath, slow down and learn.!
Post a picture of what you are looking at if you wish to find out. But take heed in my suggesting you learn what it is you want to do. It's not as easy as it seems or videoed. They leave out all the good stuff. Like how to do it the right way and safely.

B.S.
Hoke wrote a book many years ago that is perfect reading for anyone interested in learning this field. It's free here on the forum but I make you find it. Part of the learning process is how this site/forum works.


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## JWalker (Sep 30, 2013)

@ Gold4Mike:
I am currently at work but I can and will post some pics when I get home. Im +- 90% sure they are gold. They are part of a large volume of electronic connector scrap I bought. I contacted the manufacturer about some of the stuff I was unsure of and they informed me that all the items in that product line were gold plated. (Joy Signal, Chico Ca. 95928. MMCX Coax Connector series.) Also they are exactly the same color as the rest of the MMCX connectors. I have some anodized parts of various kinds to compare color from time to time. 

Also, anytime I think there might be a question as to the plating/metal I ask myself if the manufacturer would have reason to spend the money on PM plating. In this case i believe these are either mass power connectors or grounding blocks, gold makes sense in this application. Go kart sprocket? Possibly as a protective coating but I would be leaning toward no because I cant really think of a good reason to plate.

@Pantherlikher
Yep, new to this forum this month. What an amazing place. It became even better when I changed browsers and got the search to work =) But Read I have. Quite a lot actually. Along with my wife we have spent about 2 hours a day on the forum. Yes, I have seen some Youtube videos but that is a place to learn about ideas, not processes. That is a place to see where others went wrong, inform yourself, and learn what they did not. I have yet to read Hoke's book. (Not all of it anyway) And while I believe I have a good grasp on the processes I am running I will always ask/research before going into anything even remotely as dangerous as working with theses processes and become quite comfortable before I attempt them. And even then I attempt in small-scale before going into production. 
I'm sure the answer to my question is in Hoke's book. It would be strange if it were not. However, I have a buyer for this scrap if I cannot process it in my Sulfuric Cell and I was curious about the reaction of Aluminum with the cell. As soon an i can I will post the pictures of the pieces of plated Aluminum. And, as always, I regard the veterans of this forum with respect and I will always heed advice given. Regardless of the answers I get here, I do plan on doing more research, finishing the book, and then possibly attempting a small scale experiment. 

thank you both for your responses.


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## g_axelsson (Sep 30, 2013)

JWalker said:


> I have read and searched, and read.
> 
> ...
> 
> ...


It doesn't sound like you have read this recent thread.
Remove Heavy Gold Plating from Aluminum Hexagonal Laser Mirrors

Actually, Hoke doesn't talk anything about gold on aluminum or gold plated objects, only plating baths. But still, you should read Hoke to get a base of knowledge to stand on.

Gold on aluminum can be put down in two different ways, plating or sputtering. If plated then there is a barrier metal between the Al and Au as you can't plate gold directly on aluminum.
Nitric acid will dissolve the thin base metal between the gold and aluminum and free the gold.
If sputtered or evaporated it is done in vacuum and puts a fine layer of gold directly onto the aluminum. In this case the trick with nitric doesn't work. As I haven't tested the sulfuric deplating cell yet I don't know if it would work. What I found working at least for me was a solution of strong nitric acid with just a bit of hydrochloric acid, it dissolves the gold without affecting the aluminum the one time I tested it. No guarantees on this method though, it might have worked just because I did it on a certain alloy.

Keep on reading and tell us how it went. Looking forward to the pictures.

Göran


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## jimdoc (Sep 30, 2013)

JWalker said:


> Sorry about the title. Should read: Gold Plated Aluminum Pins. and the "Blocks" i spoke of are 2" long, 1/4 tall, 1/4 wide and have between 20 and 30 1/16 wide holes drilled through them. Completely plated in gold.





You should be able to edit the title.

Jim


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## Pantherlikher (Sep 30, 2013)

Excelent to hear you as well as your wife...wish mine would... are learning and enjoying something together. 

Best of luck in what you seek and hope happyness is always present.

B.S.


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## JWalker (Sep 30, 2013)

1. If I changed the title, the post about what the title should be wouldn't make any sense. 
2. I have not read the Post "Remove Heavy Gold Plating from Aluminum Hexagonal Laser Mirrors" Headed there now. 
3. I really appreciate the advice and I will be looking into the Nitric acid and the intervening metal between the Aluminum and Gold. 
4. The wife and I do not have many hobbies that match, but this one seems to have grown on her. Thank you for the wish of luck and happiness, that was quite thoughtful. (Your wife may not enjoy your hobby, but i'm sure the benefits are shared with enthusiasm  )


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## jimdoc (Sep 30, 2013)

JWalker said:


> 1. If I changed the title, the post about what the title should be wouldn't make any sense.



Well then that would have to get edited also, 
or maybe a moderator can fix it.

Jim


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## JWalker (Sep 30, 2013)

jimdoc said:


> JWalker said:
> 
> 
> > 1. If I changed the title, the post about what the title should be wouldn't make any sense.
> ...



Sorry, I was going for sarcastic/funny. Missed the mark again.....


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## JWalker (Sep 30, 2013)

Here a couple of pictures of the plated Al components.


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## niteliteone (Oct 1, 2013)

I've done many Gold Plated aluminum pieces from NASA's space program in the sulfuric cell. Just watch what you are doing and watch the amperage, making sure to remove the piece when the amperage drops low the first time. Which means the gold is finished dissolving.
If you leave the piece in much longer the amperage will start to rise again as the aluminum starts reacting and making a mess.


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## JWalker (Oct 1, 2013)

niteliteone said:
 

> I've done many Gold Plated aluminum pieces from NASA's space program in the sulfuric cell. Just watch what you are doing and watch the amperage, making sure to remove the piece when the amperage drops low the first time. Which means the gold is finished dissolving.
> If you leave the piece in much longer the amperage will start to rise again as the aluminum starts reacting and making a mess.



Thank You! After what others have posted and the links they have provided, I did my homework and found that what I have will work nicely! But it is great to hear that you have done it personally and the tip for the amperage rising again when reacting with the Al helps a lot!


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