[sdiy] preventing corrosion on bare traces

[Happy Harry]

I'd still say that protecting the traces is not necessary for
prevention of tarnish (copper oxide). If you have a trace that is
corroded through, its a sure bet that the culprit is an agressive flux 
(maybe acid core from an ignorant repair job ???) or some other foreign 
agent (James Bond perhaps?).

A spray coating could help protect against coffee, soda pop, other
liquids... if you will encounter them, use a spray !!!

H^) harry


>From: Ingo Debus <debus at cityweb.de>
>To: synth-diy at node12b53.a2000.nl
>Subject: Re: [sdiy] preventing corrosion on bare traces
>Date: Mon, 30 Apr 2001 15:34:06 +0200
>
>
>
>harry wrote:
> >
> > The copper oxide that forms on the boards will protect the rest of the 
>copper.
>
>Hmmm... I've once seen a copper PCB trace corroded so badly that it
>didn't conduct anymore. This was in an old electronic organ. The trace
>wasn't interrupted completely, but there was loud rumble in the signal.
>Soldering a wire across that trace fixed the problem.
>
> > Spray is unnecessary unless you think it looks ugly. Rework will involve
> > scraping
> > the copper to fresh metal... or removing the spray anyway.
>
>I've often used SK20 spray (Kontakt Chemie). It's not required to remove
>the spray for soldering afterwards.
>
>But it's not good if really high impedances are involved (like in sample
>& hold circuits).
>
>Ingo
>
>

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