Homebrew_PCBs

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.

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]

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
>
>
>

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@...

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]

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
>
>
>
>
>

On Tue, Mar 12, 2013 at 6:52 PM, Missouri Guy <n0tt1@...> wrote:

> **
>
> . . . 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? . . .
>

Charlie,

I don't know anything about the photoreactivity of the mixture. The high UV
from the sun probably does something. The stuff should definitely be used
outside as it has very pungent fumes, mostly from the acid I think. Care
must be taken in just opening the acid jug, it's that strong. Naturally,
proper protection for the eyes and bare skin is in order. I use shop
goggles and exam gloves and I wear old cloths. In this winter cold, I used
a rigged-up vent booth in my laundry room for both small-object spray
painting and etching. A strong fan in the back of a big cardboard box just
blows the fumes out the window.

Regarding disposal, there has been a thread running lately in this group
you should look up. Since I use my 2:1 etchant "one-shot" in 2oz
quantities, I once just poured it down the drain afterwards. Deciding that
was not responsible, I then began to dump the "shots" into a bucket filled
with wood shavings. I assumed the shavings would "sequester" (oh, that
word!!) the copper-ladden chemical in a form that, once dry, could just be
carefully bagged and sent to the landfill.

This morning, though, I read a post from . . . damn!, can't remember his
name . . . who observed all I was doing was to create more toxic waste. He
suggested the spent etchant be treated with sodium carbonate. This would
have two benefits: it would neutralize the acid, and it would precipitate
an insoluble copper compound that could then be filtered out and dried
before ordinary disposal. He further suggested the precipitate could be
made even safer by baking out carbon in the form of CO2, leaving behind . .
. damn! I can't remember the compound that would remain . . . but he said
it could be very safely disposed of in the landfill. I'm going to pursue
this idea. Check out the thread.

73,

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


[Non-text portions of this message have been removed]

OK, thanks Todd. Nasty fumes from the stuff!! I think I'll just
stick with the Ferric Chloride....seems to be the most "user friendly"
for occasional use.

Good idea on the vent system you have there!

73,
Charlie

On Tue, 12 Mar 2013 22:25:31 -0700 "Todd F. Carney / K7TFC"
<k7tfc@...> writes:

On Tue, Mar 12, 2013 at 6:52 PM, Missouri Guy <n0tt1@...> wrote:

> **
>
> . . . 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? . . .
>

Charlie,

I don't know anything about the photoreactivity of the mixture. The high
UV
from the sun probably does something. The stuff should definitely be used
outside as it has very pungent fumes, mostly from the acid I think. Care
must be taken in just opening the acid jug, it's that strong. Naturally,
proper protection for the eyes and bare skin is in order. I use shop
goggles and exam gloves and I wear old cloths. In this winter cold, I
used
a rigged-up vent booth in my laundry room for both small-object spray
painting and etching. A strong fan in the back of a big cardboard box
just
blows the fumes out the window.

Regarding disposal, there has been a thread running lately in this group
you should look up. Since I use my 2:1 etchant "one-shot" in 2oz
quantities, I once just poured it down the drain afterwards. Deciding
that
was not responsible, I then began to dump the "shots" into a bucket
filled
with wood shavings. I assumed the shavings would "sequester" (oh, that
word!!) the copper-ladden chemical in a form that, once dry, could just
be
carefully bagged and sent to the landfill.

This morning, though, I read a post from . . . damn!, can't remember his
name . . . who observed all I was doing was to create more toxic waste.
He
suggested the spent etchant be treated with sodium carbonate. This would
have two benefits: it would neutralize the acid, and it would precipitate
an insoluble copper compound that could then be filtered out and dried
before ordinary disposal. He further suggested the precipitate could be
made even safer by baking out carbon in the form of CO2, leaving behind .
.
. damn! I can't remember the compound that would remain . . . but he said
it could be very safely disposed of in the landfill. I'm going to pursue
this idea. Check out the thread.

73,

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

[Non-text portions of this message have been removed]




[Non-text portions of this message have been removed]

Charlie,

Well, I may have overstated the nastiness of the fumes. It's really no
worse in use than, say, photo stop bath or fixer--both of which have a
fairly-strong acetic-acid (vinegar) smell. There's no evil-scientist smoke
or anything. For me, it's a kind of DIY thing. I make my own salad
dressing, too . . . not with the hydrochloric, mind you!

73,

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

On Wed, Mar 13, 2013 at 9:09 AM, Missouri Guy <n0tt1@...> wrote:

> OK, thanks Todd. Nasty fumes from the stuff!! I think I'll just
> stick with the Ferric Chloride....seems to be the most "user friendly"
> for occasional use.
>
> Good idea on the vent system you have there!
>
> 73,
> Charlie
>
> On Tue, 12 Mar 2013 22:25:31 -0700 "Todd F. Carney / K7TFC"
> <k7tfc@...> writes:
>
> On Tue, Mar 12, 2013 at 6:52 PM, Missouri Guy <n0tt1@...> wrote:
>
> > **
> >
> > . . . 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? . . .
> >
>
> Charlie,
>
> I don't know anything about the photoreactivity of the mixture. The high
> UV
> from the sun probably does something. The stuff should definitely be used
> outside as it has very pungent fumes, mostly from the acid I think. Care
> must be taken in just opening the acid jug, it's that strong. Naturally,
> proper protection for the eyes and bare skin is in order. I use shop
> goggles and exam gloves and I wear old cloths. In this winter cold, I
> used
> a rigged-up vent booth in my laundry room for both small-object spray
> painting and etching. A strong fan in the back of a big cardboard box
> just
> blows the fumes out the window.
>
> Regarding disposal, there has been a thread running lately in this group
> you should look up. Since I use my 2:1 etchant "one-shot" in 2oz
> quantities, I once just poured it down the drain afterwards. Deciding
> that
> was not responsible, I then began to dump the "shots" into a bucket
> filled
> with wood shavings. I assumed the shavings would "sequester" (oh, that
> word!!) the copper-ladden chemical in a form that, once dry, could just
> be
> carefully bagged and sent to the landfill.
>
> This morning, though, I read a post from . . . damn!, can't remember his
> name . . . who observed all I was doing was to create more toxic waste.
> He
> suggested the spent etchant be treated with sodium carbonate. This would
> have two benefits: it would neutralize the acid, and it would precipitate
> an insoluble copper compound that could then be filtered out and dried
> before ordinary disposal. He further suggested the precipitate could be
> made even safer by baking out carbon in the form of CO2, leaving behind .
> .
> . damn! I can't remember the compound that would remain . . . but he said
> it could be very safely disposed of in the landfill. I'm going to pursue
> this idea. Check out the thread.
>
> 73,
>
> Todd
> ----------------------------------------------------------
> K7TFC / Medford, Oregon, USA / CN82ni / UTC-8
> ----------------------------------------------------------
> QRP (CW & SSB) / EmComm / SOTA / Homebrew / Design
>
> [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]

WOW!

I've been reading all this chaff about what my Mom called "peroxide",
and how, ever since I can remember, there
was always a bottle of this stuff somewhere in the house. No one ever
got gassed, burned, blistered, or was
rendered unconscious by the stuff, and she spilled on all three of her
kids whenever we fell down and scrapped
a knee or cut a finger. Of course, the stuff we had in the house was
the "ordinary" stuff she purchased at the
Rexall drug store along with iodine and Band-Aids.

Well, many, many years later, I still have at least a liter of the stuff
in the house and another out in my
workplace. I use the workplace "stash" for making printed circuit boards.

Living in southern Arizona on the Sonoran Desert, nearly everyone has a
backyard swimming pool, or at least
there are three or four on every block. That means that most garages or
backyard sheds have several gallons
of muriatic acid sitting around. You need the stuff to maintain your
pool. I've never witnessed or even heard
of any catastrophes in having a neighborhood that is loaded down with
5-gallon jugs of the stuff.
Of course, one must use basic intelligence in using the stuff.

I've lived here for nearly 30 years, and I have never heard of anyone
getting messed up from muriatic acid.
OR drug store peroxide. You "Google" muriatic acid and find out what it is.

When making a PC board, I just mix up the generally recommended compound
of 75% peroxide, and
25% muriatic acid. The stuff works on 1-oz. copper like a "dose of Epson
Salts through a widow woman",
as my Grandpa used to exclaim.

The caveats are: Use the rule you learned in high school chemistry class
about how to mix acids with other
things, including water, and to always work with and use chemicals (of
any type) in a well-vented area.

No need to get fancy or get exotic. The above compound works well at
room temp. I usually do my etching
outdoors because I can take advantage of the usual 100 degree heat that
we get, free of charge, most of
the year out here in "rattlesnake country". Chemical reactions are
speeded up by application of heat.
I learned that in high school chem. class also......as long as you don't
" overshoot the groove".

Life is really pretty easy...........if you don't fight it.

Roland F. Harriston, P.D.
***************************

On 3/13/2013 11:59 AM, Todd F. Carney / K7TFC wrote:
>
> Charlie,
>
> Well, I may have overstated the nastiness of the fumes. It's really no
> worse in use than, say, photo stop bath or fixer--both of which have a
> fairly-strong acetic-acid (vinegar) smell. There's no evil-scientist smoke
> or anything. For me, it's a kind of DIY thing. I make my own salad
> dressing, too . . . not with the hydrochloric, mind you!
>
> 73,
>
> Todd
> ----------------------------------------------------------
> K7TFC / Medford, Oregon, USA / CN82ni / UTC-8
> ----------------------------------------------------------
> QRP (CW & SSB) / EmComm / SOTA / Homebrew / Design
>
> On Wed, Mar 13, 2013 at 9:09 AM, Missouri Guy <n0tt1@...
> <mailto:n0tt1%40juno.com>> wrote:
>
> > OK, thanks Todd. Nasty fumes from the stuff!! I think I'll just
> > stick with the Ferric Chloride....seems to be the most "user friendly"
> > for occasional use.
> >
> > Good idea on the vent system you have there!
> >
> > 73,
> > Charlie
> >
> > On Tue, 12 Mar 2013 22:25:31 -0700 "Todd F. Carney / K7TFC"
> > <k7tfc@... <mailto:k7tfc%40arrl.net>> writes:
> >
> > On Tue, Mar 12, 2013 at 6:52 PM, Missouri Guy <n0tt1@...
> <mailto:n0tt1%40juno.com>> wrote:
> >
> > > **
> > >
> > > . . . 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? . . .
> > >
> >
> > Charlie,
> >
> > I don't know anything about the photoreactivity of the mixture. The high
> > UV
> > from the sun probably does something. The stuff should definitely be
> used
> > outside as it has very pungent fumes, mostly from the acid I think. Care
> > must be taken in just opening the acid jug, it's that strong. Naturally,
> > proper protection for the eyes and bare skin is in order. I use shop
> > goggles and exam gloves and I wear old cloths. In this winter cold, I
> > used
> > a rigged-up vent booth in my laundry room for both small-object spray
> > painting and etching. A strong fan in the back of a big cardboard box
> > just
> > blows the fumes out the window.
> >
> > Regarding disposal, there has been a thread running lately in this group
> > you should look up. Since I use my 2:1 etchant "one-shot" in 2oz
> > quantities, I once just poured it down the drain afterwards. Deciding
> > that
> > was not responsible, I then began to dump the "shots" into a bucket
> > filled
> > with wood shavings. I assumed the shavings would "sequester" (oh, that
> > word!!) the copper-ladden chemical in a form that, once dry, could just
> > be
> > carefully bagged and sent to the landfill.
> >
> > This morning, though, I read a post from . . . damn!, can't remember his
> > name . . . who observed all I was doing was to create more toxic waste.
> > He
> > suggested the spent etchant be treated with sodium carbonate. This would
> > have two benefits: it would neutralize the acid, and it would
> precipitate
> > an insoluble copper compound that could then be filtered out and dried
> > before ordinary disposal. He further suggested the precipitate could be
> > made even safer by baking out carbon in the form of CO2, leaving
> behind .
> > .
> > . damn! I can't remember the compound that would remain . . . but he
> said
> > it could be very safely disposed of in the landfill. I'm going to pursue
> > this idea. Check out the thread.
> >
> > 73,
> >
> > Todd
> > ----------------------------------------------------------
> > K7TFC / Medford, Oregon, USA / CN82ni / UTC-8
> > ----------------------------------------------------------
> > QRP (CW & SSB) / EmComm / SOTA / Homebrew / Design
> >
> > [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]