Todd,
IMV, that makes more sense to me than to mix more exotic
chemicals and it's easy to get. No need to make "rocket fuel"
out of the H2O2!! :D)
Lemme ask this...I'm assuming that the etching should NOT be
done in full sunlight because of the H2O2. Is that correct?
Or does it make any difference because it is mixed with the
hydrochloric acid?
I missed any talk about safe disposal of this particular brew
of the drug store peroxide and hydrochloric acid. So again
on that please...thanks!
Charlie
On Tue, 12 Mar 2013 18:05:59 -0700 "Todd F. Carney / K7TFC"
<
k7tfc@...> writes:
> My etchant is two parts by volume of 3% H2O2 and 1 part 35%
> "muriatic"
> (hydrochloric) acid. The peroxide is just the drug store/supermarket
> stuff.
> The acid is from Home Depot. It's sold for concrete cleaning/prep.
>
> This etchant works pretty fast and I don't think I'd ever need
> stronger
> peroxide.
>
> The 3% I buy is about $1.50 a quart. The acid's about $10 a gallon.
>
> 73,
>
> Todd
>
-------------------------------------------------------------------------
-----------
> K7TFC / Medford, Oregon, USA / CN82ni / UTC-8
>
-------------------------------------------------------------------------
-----------
> QRP (CW & SSB) / EmComm / SOTA / Homebrew / Design
>
>
> On Tue, Mar 12, 2013 at 4:49 PM, Peter Harrison
> <peter.harrison@...
> > wrote:
>
> > ∗∗
> >
> >
> > Oops!
> >
> > 60vol would be 18%
> >
> >
> > On 12 Mar 2013, at 23:34, Peter Harrison wrote:
> >
> > > Actually, Hydrogen Peroxide in strengths of 30% and upwards is
> > potentially very unpleasant and becomes increasingly dangerous if
> not
> > handled and stored correctly.
> > >
> > > Note, this is 30% by weight. It may also be described as 100vol.
> That
> > means it will release 100 times its liquid volume of pure oxygen.
> > >
> > > Read this:
> > >
> > > http://www.sciencelab.com/msds.php?msdsId=9924299
> > >
> > > and this:
> > >
> > > http://www.hpa.org.uk/webc/HPAwebFile/HPAweb_C/1246260031375
> > >
> > > and be sure you are completely clear whether the strength of the
> H2O2
> > you have is, say, 20vol or 20%. The stuff used in hair bleach is
> going to
> > be about 3% which is 10vol. I am reasonably sure that the
> strongest you are
> > likely to find in a hairdressing wholesaler will be about 20%
> (60vol). It
> > is sold for dilution by the salon before use.
> > >
> > > Peter Harrison
> > >
> > >
> > >
> > >
> > > On 12 Mar 2013, at 18:33, Eddie Stassen wrote:
> > >
> > >> Being safety concious is always good, but ffs you are not going
> to
> > require
> > >> amputation from a drop of peroxide on your finger. Whitened
> skin, some
> > >> stinging or in extreme cases some blistering perhaps
> > >>
> > >>
> > >> On Tue, Mar 12, 2013 at 7:51 PM, smilingcat90254
> > >> <smilingcat@...>wrote:
> > >>
> > >>> ∗∗
> > >>>
> > >>>
> > >>> First of all, distilling hydrogen peroxide from pharmacy grade
> 3%
> > VOLUME
> > >>> peroxide is relatively easy. I posted it some time ago and
> some one
> > >>> recently said it as well. It's by freezing and throwing away
> the ice
> > that
> > >>> forms.
> > >>>
> > >>> ∗∗∗∗ safety ∗∗∗∗
> > >>> You need to be extremely careful in handling this concentrated
> stuff.
> > You
> > >>> can only reach about 40 some odd percent concentration by
> freezing.
> > Still,
> > >>> its "dangerous". I've accidentally had few droplets hit my
> finger (Yes
> > I
> > >>> should have been wearing my chemical gloves but I wasn't) and
> the skin
> > >>> where the droplet hit, the skin immediately turned white,
> chemical
> > burn.
> > >>> Then the liquid penetrated into the dermis, layer of skin
> where there
> > are
> > >>> blood vessels and nerves. And the painful stinging sensation
> from the
> > >>> peroxide burn was really intense. It was good that I had the
> > sensation. Had
> > >>> it stopped, then it would have meant that my finger would have
> to been
> > >>> amputated...
> > >>>
> > >>> ∗∗∗∗Another safety aspect of handling peroxide∗∗∗∗
> > >>> DO NOT EXPOSE TO UV OR EVEN BLUISH LIGHT (florescent light,
> sunlight
> > is a
> > >>> big NO NO).
> > >>>
> > >>> DO NOT LET IT COME IN CONTACT WITH ANY METAL ESPECIALLY IRON
> BASED
> > >>> MATERIAL. This includes all stainless steel. Iron act as a
> catalyst to
> > >>> decompose peroxide into oxygen and water.
> > >>>
> > >>> Store in clean dark brown bottle but it should not be so
> airtight
> > >>> that it can build up pressure. Countless number of explosions
> have
> > >>> happened because of this most famous is the accidental sinking
> of
> > Russian
> > >>> super sub the Kursk.
> > >>>
> > >>> ∗∗∗∗ Side note ∗∗∗∗
> > >>> do not confuse volume concentration such as 3% vol H2O2 with
> 3% H2O2.
> > big
> > >>> difference. You can not get 90% H2O2 nor can you make it at
> home
> > unless you
> > >>> know lot about chemistry and have the right equipment.
> > >>>
> > >>> Concentrating H2O2 by freezing is more than plenty good for
> your
> > etching
> > >>> need!! Don't make it any more dangerous than need to be.
> > >>>
> > >>>
> > >>>
> > >>
> > >>
> > >> [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
> > >>
> > >>
> > >>
> > >
> > >
> > >
> > > ------------------------------------
> > >
> > > Be sure to visit the group home and check for new Links, Files,
> and
> > Photos:
> > > http://groups.yahoo.com/group/Homebrew_PCBsYahoo! Groups Links
> > >
> > >
> > >
> >
> > Peter Harrison
> > peter.harrison@...
> >
> >
> >
>
>
> [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
>
>
>
>
>