Author Topic: New Plating Process  (Read 1023 times)

Offline dencins

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New Plating Process
« on: October 29, 2011, 01:20:03 AM »
With the help of a chemistry forum, I have added a new process for a copper “flash” on carbon steel parts.  I have found a copper layer under the nickel when stripping many steel telephone parts.  I did some research and found the copper layer was used for added corrosion protection on carbon steel.  Nickel plating can have microscopic holes that allow moisture to get under the nickel and can cause the iron to rust.  The copper layer helps avoid this but the most common copper “flash” processes use cyanide.

My criteria for the new process was to use material readily available at local stores, be low cost and does not use cyanide.  It does plate slow which would not interest professional platers but works very well for a hobbyist.  The adhesion is excellent.  Previously I was trying to use acid copper for a “flash” but it was not predictable.  Sometimes it would have good adhesion and other times it would immersion plate with poor to no adhesion.

The chemicals to make the solution are:

Copper Sulfate (Root Killer from local hardware store)
Citric Acid (found at India Spice Store)
Sodium Hydroxide (Roebic Crystal Drain Opener (lye) at Lowe’s)
Distilled Water     

I have recently used the new process for plating the steel parts on a Century and a Chicago wood wall phones with excellent results.  While doing parts like hinges and binding posts, I found the copper “flash” also provided excellent coverage over solder.  Solder is a problem with nickel plate since it turns black.   

Another benefit - it can be used as a copper “flash” on pot metal (die cast zinc) parts before nickel.  I have been testing it on the blocks from an AE40 Butler Handle with very good results.  Pot metal dissolves very quickly when exposed to acid.  A layer of alkaline copper protects the pot metal while plating with nickel.

I have found Caswell’s B-929 does a good job removing old nickel from pot metal (as well as brass).  Not a lot of telephone parts used chrome (Automatic Electric used it on some parts) but if needed I have been using a 10 % Muriatic Acid solution to strip the  chrome.  The problem is if there are any areas with bare pot metal, this will immediately start to dissolve the part.  Since chrome is very thin, an alternative to remove it is sanding then strip the nickel.  I will continue to look for alternatives to remove chrome.

Dennis Hallworth

Offline AE_Collector

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Re: New Plating Process
« Reply #1 on: October 29, 2011, 02:26:03 AM »
Very interesting research Dennis. This is a very good service that you are providing the telephone collecting community.



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Re: New Plating Process
« Reply #2 on: October 29, 2011, 10:36:39 AM »
Very good Dennis.


Offline teka-bb

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Re: New Plating Process
« Reply #3 on: October 29, 2011, 03:14:10 PM »

Thanks for sharing Dennis, very interesting.

Remco, JKL Museum of Telephony Curator

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AKA "dialmaster", AKA"Doc Remco."

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Offline old_stuff_hound

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Re: New Plating Process
« Reply #4 on: October 29, 2011, 07:18:36 PM »
Hi Dennis,

That's very interesting!

I still have those governor linkage pieces I need to send you -- I haven't forgotten. I'll be in touch!