Remember that a lot of waste lines are made of copper alloys (brass and such) and even small amounts of FeCl will etch them away over time.
Donald.
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----- Original Message -----
> From: "Jan Kok" <jan.kok.5y@...>
> To: "Homebrew PCBs" <Homebrew_PCBs@yahoogroups.com>
> Sent: Wednesday, January 26, 2011 6:29:47 PM
> Subject: Re: [Homebrew_PCBs] Re: Building an etching tank?
>
> On Wed, Jan 26, 2011 at 1:41 PM, Nathan House
> <nathanhooyagroups@...> wrote:
> >>Just tried the brushing-with-sponge technique, with excellent results.
> >
> > Well, maybe I should give ferric chloride a try then. It would avoid the
> > rust problem which I only recently learned about, is probably safer to use
> > (there aren't any fumes with ferric chloride, correct?). Do you just wash
> > off the sponge in the sink afterwords?
>
> I did the etching while holding the board above or in a plastic
> dishwashing basin. I had a 1-liter glass beaker filled with water
> which I used to rinse off the board a couple times to get a better
> look at the etching progress, and then in the end to rinse out the
> sponge and gloves. Then carefully poured the contaminated water down
> the drain, rinsed out the dishwashing basin and poured that water
> carefully down the drain, then not-so-carefully rinsed everything
> again in the laundry sink. I could probably do that hundreds of times
> without staining anything. It was less mess than I expected, really
> not much mess at all.
>
> I noticed some fumes from the FeCl3 when I heated it in an open
> beaker, but didn't notice any fumes at all when using it cold. (Not
> that I put my nose close to the opening of the bottle... :-)
>
> Cheers,
> - Jan