Homebrew PCBs

On 8/19/2011 11:16 AM, kx4om wrote:
>
> Before I posted, I did a search in the archives for "vinegar". 
> Returned several hits. Here is a link to a web article where the 
> etching process does indeed use household vinegar (with 
> drugstore-strength hydrogen peroxide and table salt.)
>
> http://quinndunki.com/blondihacks/?p=351
>
> _
Not 100% sure about the chemistry - it's been 60+ years since chem 
classes, but as I recall, vinegar (5% acetic acid, HAc) + Salt (sodium 
chloride, NaCl) => HCl (hydrochloric acid) + NaAc (sodium acetate?).  It 
would be a very weak HCl, and when combined with the drugstore H2O2  
yields a very weak version of the same etchant as  the CuCl version 
(just add copper).  I have no idea what the NaAc might contribute to the 
etching process. The very weak acid/oxidizer solution  tends to agree 
with quindunki's report of very slow etching time__ 
<http://quinndunki.com/blondihacks/?p=351> (1 hour +).   It obviously 
works for him, and possibly the very weak etchant contributes to his 
success with fine traces.  To me, the commercial HCl is easier and 
faster than messing with kitchen condiments.

Just my opinion - - - YMMV.

Norm
W6NIM


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