# Silver plated aluminum???



## silversaddle1 (Apr 8, 2010)

OK guys, help me out here. I have a chance to purchase a whole semiload of tele/cellular/networking rack gear. A lot of the stuff is stuff we have seen before, but there are some things I've never seen before and need some input on. Take a look at the photos and tell me what you think. It sure looks to be silver plated. The color is right, has the tarnish from heating (silversmiths call this firescale I believe). SO is it plated? And if so, why?

I'm not sure, but I think the big piece is some sort of signal filter maybe? Not much to it, but it is heavy!

Any ideas?


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## silversaddle1 (Apr 8, 2010)

2


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## silversaddle1 (Apr 8, 2010)

3


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## silversaddle1 (Apr 8, 2010)

4


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## silversaddle1 (Apr 8, 2010)

Smaller box


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## silversaddle1 (Apr 8, 2010)

2


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## Barren Realms 007 (Apr 8, 2010)

Put some HCL in some test spots and see if you get reactions. Looks like just aluminum. Why would they need to plate with silver.


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## goldsilverpro (Apr 8, 2010)

Just some ideas.

You might put a little 50/50 nitric (see EDIT below) in one of those small cavities, like on the right in pic#2. Let it set for awhile and then transfer the solution into a beaker with a squirt bottle. Test the solution with weak HCl or salt water for AgCl.

You could also test the surface with Schwerter's solution. Ag gives a red color

In the photos, it looks like it could be nickel plate, especially in pic#3. Silver is the whitest metallic element there is. Nickel could be confirmed by dissolving in nitric, making the solution ammoniacal, and using DMG. However, be aware that, if it is Ag plated, there is a good chance that there is nickel plate under the silver. This could confuse the issue.

You might be able to peel a little of the plate by tapping an area with a ball peen hammer. If the plating can be made to stretch laterally, it will pop loose.

You might be able to flake some of the plating off by using a little 50/50 HCl in one of those cavities. If the plating is porous at all, the HCl could undermine the plating, attack the Al, and flake off the plating. If the HCl readily attacks the metal, with no plating flakes observed, it is probably unplated Al.

If it is silver plated, the best way I can think to strip it is in nitric acid. Most Al alloys won't be attacked, but some will, especially when the solution gets hot. Although most references say that Al isn't attacked by HNO3, I have seen it happen under certain conditions or with certain alloys. If nitric works without attacking the Al, I would probably strip them one by one in an open top plastic drum and then drain them well and dip them in a couple of rinses.
EDIT:  I just thought of this. Nitric might not work at all. The Al, if it is soluble at all, might reduce the dissolved silver back to metal as fast as you can dissolve it. If it is silver plate and, if nitric won't work, you might just have contaminated aluminum, unless someone can come up with another way to strip the silver.

I have stripped Au from Al in the electrolytic conc. sulfuric cell with no attack on the Al. You might strip Ag with this but, with all the cavities on those parts, you could have a mess. Also, you would have problems throwing current into those cavities. Also, you would have to figure out how to get the Ag out of the stripper.

Do you see any peeling where the torch was applied? Heating will often pop the plating loose.

The reason I was thinking of ways to pop some of the plating off is that it might be easier to test it if you could isolate it from the Al.

If you do buy this stuff, you might end up owning what is known in the scrap business as a "white elephant"

Another crazy idea. I once stripped Rh plate off of jewelry using steel shot peening. As mentioned above, the peening stretched the plating and it popped off. *IF* no nickel is present, the steel shot could be separated magnetically.


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## silversaddle1 (Apr 8, 2010)

Barren Realms 007 said:


> Put some HCL in some test spots and see if you get reactions. Looks like just aluminum. Why would they need to plate with silver.



It's plated with something. Never seen aluminum tarnish black before.


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## silversaddle1 (Apr 8, 2010)

goldsilverpro said:


> You could put a little 50/50 nitric in one of those small cavities, like on the right in pic#2. Let it set for awhile and then transfer the solution into a beaker with a squirt bottle. Test the solution with weak HCl or salt water for AgCl.
> 
> You could also test the surface with Schwerter's solution. Ag gives a red color
> 
> ...




Hey GSP, how about I just send you a sample. :lol:


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## goldsilverpro (Apr 8, 2010)

> Hey GSP, how about I just send you a sample



I'd rather you wouldn't. I would enjoy playing with it, but I don't have any place to work since closing the assay business. Also, I don't have some of the chemicals.


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## silversaddle1 (Apr 8, 2010)

goldsilverpro said:


> > Hey GSP, how about I just send you a sample
> 
> 
> 
> I'd rather you wouldn't. I would enjoy playing with it, but I don't have any place to work since closing the assay business. Also, I don't have some of the chemicals.



I did not know you closed it down, sorry to hear that.


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## Anonymous (Apr 8, 2010)

Its not aluminum at all it should be titanium or an alloy


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## silversaddle1 (Apr 8, 2010)

Enigma said:


> Its not aluminum at all it should be titanium or an alloy



Interesting. Why would it be titanium?


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## Anonymous (Apr 8, 2010)

may not be titanium,but an alloy.but is not aluminum


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## goldsilverpro (Apr 8, 2010)

> may not be titanium,but an alloy.but is not aluminum


What sort of alloy did you have in mind? Why do you think it isn't Al?

If it's silver/gray, light weight, non-magnetic, and doesn't spark on a grindstone, I would think it would be Ti, Al, or Mg. If you can easily cut a sliver off the edge with a pocket knife, it is likely Al and surely isn't Ti. To distinguish between Mg and Al, put a drop of silver nitrate on it. If it turns black, it is Mg.

In grams, weigh a piece in air and then suspended in water and calculate the density. Subtract the weight in water from the weight in air. Divide this answer into the weight in air. Al = about 2.7, Ti = 4.5, Mg = 1.7


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## Anonymous (Apr 8, 2010)

> If you can easily cut a sliver off the edge with a pocket knife


then simply try to ingite with torch.if burns then magnesium.but is not Al


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## kdaddy (Apr 8, 2010)

I have removed and scrapped many of these. Silver plated aluminum. The larger one is called a TMA. The cylinders in each square cell are brass or copper plated with silver. I have found no economical way to recover the silver. If you can get the radio cards from the BTS cabinets thats where the good stuff is. By the way I work in the cell tower industry.

Keith


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## goldsilverpro (Apr 8, 2010)

Thanks a lot, Keith,

Sounds like good reliable information. I thought it had to be Al. The copper throws a big wrench in the works, as far as recovering the Ag is concerned. Looks like it is nothing but Al/Cu breakage.


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## Barren Realms 007 (Apr 8, 2010)

Could this be reverse plated in a used nitric cell?


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## kdaddy (Apr 8, 2010)

The copper or brass cylinders are usually removable from the housing via a single torx screw in the center cavity of the cylinder.
I usually remove them and save till I get a couple of buckets full. I wish I could find somewhere that would pay a little extra for 
the silver content but no luck so far. They are free to me so it's all good.

Keith


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## Anonymous (Apr 8, 2010)

> Thanks a lot, Keith,
> 
> Sounds like good reliable information.


yes thank you kieth,there is obviously no way in hell anyone else could have possibly been correct


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## qst42know (Apr 8, 2010)

You might try some sodium hydroxide on a small piece of the aluminum. 

I had some buss bars of plated aluminum cut into short pieces that when reacted for a time in lye the plate shed like a skin and still left most of the aluminum for the scrap bin.


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## meng2k7 (Apr 12, 2010)

hi!

those are aluminum with silver platings, you will notice the discolourations of silver platings, u can recover the silver by washing it with some 10% nitric over and over until all platings dissolved, salt it. :wink: 

follow steve's silver chloride conversion on his website.


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## lunker (Apr 13, 2010)

If they are copper or brass try steaming them with a 30% solution of water and nitric. i use a crock pot to heat the solution and a ice cream pail to hold the parts. i place a pail of ice on top to condence the steam. After a few hours i turn off the crock pot and let the parts dry for a day or two. dump out the parts and shake off the plating. It seems crazy but it works well if your patient. Best of luck!


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## pinwheel (Apr 28, 2010)

Definitely appears to be silver tarnish or heated silver plating. I cant get anyone to pay extra for Ag covered Cu busbars so I doubt anyone will for this. Why the plating? Are they conducting over the box?


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## Barren Realms 007 (Apr 28, 2010)

pinwheel said:


> Definitely appears to be silver tarnish or heated silver plating. I cant get anyone to pay extra for Ag covered Cu busbars so I doubt anyone will for this. Why the plating? Are they conducting over the box?



Possibly grounding?? 8)


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