Homebrew PCBs

Yes, ferric chloride is a mess. I'm using a peroxide-hydrochloric acid
etchant that I use in very small quantities (2oz) and then toss. In old
darkroom terms, I use it "one-shot." The peroxide and acid are super cheap,
and I like the repeatability that comes with using fresh etchant every
time.

However, a while ago I became concerned about just dumping the stuff down
the drain--not because of the peroxide or acid--but because of the
dissolved copper. So I had an old 5-gal plastic bucket and I filled it with
wood shavings (I had a lot of it for now-deceased hampsters). I now dump my
2oz shots straight into that. I keep it out of the rain, but *outside*. I
just set the lid on it. I'm afraid to snap it down for fear of some kind of
build up. I'm expecting I can use this bucket, with it's current load off
shavings, for many years. Ultimately, I (or my heirs) will double or triple
bag it in its snapped-down bucket and toss it out.

Oh, I haven't done it yet, but I've gonna use a big fat permanent marker
and write "poison," "copper compounds," "Do not dispose without caution,"
or words to those effect, all over the bucket. I guess if you have kids or
snoopy dogs, you'd want to keep the bucket where they can't get to it.

73,

Todd
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K7TFC / Medford, Oregon, USA / CN82ni / UTC-8
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QRP (CW & SSB) / EmComm / SOTA / Homebrew / Design


On Sun, Mar 10, 2013 at 5:43 PM, Charlie Taylor <scubadogct@...>wrote:

> Well im sure you are correct but either way in the world of sewerage that
> is what the issue is with diaposing used ferric chloride.
> On Mar 10, 2013 11:31 PM, "Todd F. Carney / K7TFC" <k7tfc@...> wrote:
>
> > **
> >
> >
> > Neither iron nor copper are actually "heavy." Atomic number is part of
> the
> > definition. Fe (iron): 26 / Ni (nickel): 28 / Cu (copper): 29 / Zn
> (zinc):
> > 30. Each of these needed by all life (in the proper quantities, of
> course).
> >
> > Now, these buggers *are* heavy: Hg (mercury): 80 and Pb (lead): 82.
> Useful
> > but nasty metals.
> >
> > Sorry for the quibble. Heavy metals is commonly used to mean "toxic metal
> > compounds." That's okay. I need coffee. I'll feel better.
> >
> > 73,
> >
> > Todd
> > ----------------------------------------------------------
> > K7TFC / Medford, Oregon, USA / CN82ni / UTC-8
> > ----------------------------------------------------------
> > QRP (CW & SSB) / EmComm / SOTA / Homebrew / Design
> >
> > On Sun, Mar 10, 2013 at 11:30 AM, Charlie Taylor <scubadogct@...
> > >wrote:
> >
> > > in my opinon the preasence of ferric is not the issue. It is tje heavy
> > > metals that is the peoblem.
> > > On Mar 10, 2013 1:03 PM, "Dave Sage" <davesage12@...> wrote:
> > >
> > > > **
> > > >
> > > >
> > > > Perhaps someone with some knowledge on public works and sewage
> > treatment
> > > > can
> > > > clarify this for me.
> > > >
> > > > I guess it must be the copper in the ferric chloride etchant that we
> > > > dispose
> > > > of that is the problem - is that correct? Is there actually copper
> per
> > se
> > > > any more after the reaction of etching?
> > > >
> > > > I'm pretty sure somewhere in the sewage treatment process, after
> gross
> > > > solids are removed, the water in the sewage system is sent to
> settling
> > > > ponds. While in the ponds ferric chloride is added to act as a
> > flocculent
> > > > i.e. an agent that causes solids to gather together in clumps for
> easy
> > > > removal. If this is the case, would it make any difference if there
> > were
> > > > some ferric chloride in the system to begin with (from flushing
> etchant
> > > > down
> > > > the drain)?
> > > >
> > > > [Non-text portions of this message have been removed]
> > > >
> > > >
> > > >
> > >
> > >
> > > [Non-text portions of this message have been removed]
> > >
> > >
> > >
> > > ------------------------------------
> > >
> > > Be sure to visit the group home and check for new Links, Files, and
> > Photos:
> > > http://groups.yahoo.com/group/Homebrew_PCBsYahoo! Groups Links
> > >
> > >
> > >
> > >
> >
> > [Non-text portions of this message have been removed]
> >
> >
> >
>
>
> [Non-text portions of this message have been removed]
>
>
>
> ------------------------------------
>
> Be sure to visit the group home and check for new Links, Files, and Photos:
> http://groups.yahoo.com/group/Homebrew_PCBsYahoo! Groups Links
>
>
>
>


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