[Boatanchors] cleaning coppe, r and probably off topic but relevant to HF amplifiers.

[Richard Knoppow]

----- Original Message ----- 
From: "CLIVE COLLINS" <dartaviation at btopenworld.com>
To: "boatanchor network" <boatanchors at mailman.qth.net>
Sent: Monday, May 02, 2011 2:01 PM
Subject: [Boatanchors] cleaning coppe,r and probably off 
topic but relevant to HF amplifiers.


> Good evening gentlemen,
> Some time ago I read of a chemical that could be used in 
> suspension to clean discoloration from copper PA tank 
> coils. Unfortunately I have lost/mislaid the note that I 
> made of the name of the chemical. Is there a chenist 
> member who might be able to steer me to this chemical 
> please?
> Many thanks in advance.
> Regards
>
> Clive GW3WEQ North Wales Coast UK

    I replyed to Clive but meant to reply to the list. If 
its copper and not silver plated any of several oxide 
removers can be used. Naval Jelly and Tarn-X employ 
phosporic acid, which is also found in a number of tile and 
grout cleaners. Another widely used chemical is oxalic acid, 
found in cleaners like Zud and Barkeeper's Friend. Several 
other acids will remove copper corrosion but some will 
remove too much metal. For instance nitric acid is used as a 
preparation for plating.
    Silver oxide is nearly as good a conductor as metallic 
silver and should not be cleaned off because such oxide 
removal is likely to remove the silver itself.
    Once copper is cleaned it should be coated with a 
suitable varnish to protect it. Freshly cleaned copper will 
oxidize quickly.
    Copper is fairly easy to silver plate, for instance see:
http://www.on7lr.org/special/ag/ag.htm
    I think this is similar to the Brasheer's process for 
silvering mirrors.


--
Richard Knoppow
Los Angeles
WB6KBL
dickburk at ix.netcom.com