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Subject: Re: [Homebrew_PCBs] Blackening Copper

From: Adam Seychell <adam_seychell@...>
Date: 2004-05-14

Stefan Trethan wrote:
>>How about a solution composed of NaOH and H2o2?
>>You will get:
>>
>>Cu(OH) Blue in color
>>Cu(OH)2 Black in color.
>>
>>If you apply heat, the Cu(OH) will be oxidized to
>>Cu(OH)2.
>>
>>
>>
>>Best regards
>>
>>Marvin Dickens
>>
>>===
>
>
>
> Thanks, that's worth a try....
>
> The black i produced the other day didn't stick....
>

Thats interesting.
I found this doing a google search
http://doc.tms.org/ezMerchant/prodtms.nsf/ProductLookupItemID/JEM-0306-558/$FILE/JEM-0306-558F.pdf


I was wrong before, its actually sodium hydroxide and sodium
chlorite. Not sure where you get chlorites from. I thought all
the chlorite, chlorate and perchlorates are ingredients in bomb
making material so may be difficult to get in a useful form.
The order of oxidation power (lowest to highest) is

NaCl0 sodium hypochlorite
NaCl02 sodium chlorite
NaCl03 sodium chlorate
Na(Cl0) sodium perchlorate