Running low on hard drive space or something ??
Do you happen to be a moderator?
I would rather be a lonely individual , yadayada ...
Then one that has to boost their ego with needless
belittling ..
And if you can find everything you could ever need to
know in life with a simple google search ..
Then I have but one question for you .
Why are you even on this list ?
Cheers ..
Randy
________________________________
From: Roland F. Harriston <
rolohar@...>
To:
Homebrew_PCBs@yahoogroups.comSent: Mon, February 28, 2011 8:53:51 PM
Subject: Re: [Homebrew_PCBs] Re: Question for the chemistry majors !!
To All:
I've been etching PCB's with muriatic acid (20 Baume, 31.45 %
hydrochloric acid) that I purchase from a local supermarket, sold for
cleaning swimming pools. Very cheap because I live in an area where
virtually every house has a backyard swimming pool.
I use peroxide that I buy at Walgreen's drug store (3%).
I mostly etch 2oz. copper double-sided PCB's, FR4.. I always use
the above compound outdoors and try not to inhale the funes.
I use the solution once and discard it down the drain after diluting it
10 to 1 with tap water. My usual "batch" is about 8 oz.
The compound is so cheap to make, I don't see the need for saving it.
Besides, it's not a good compound to have sitting around the house.
The etch process is rather rapid, and highly satisfactory.
As an aside: This discussion has been gone over again, and again, and
again, and again, and again, and again, and again
on this and other forums for years, and years, and years, and years, and
years.
Here's a clue: A very simple Google search will give more information
than anyone actually needs to do this kind of etch process.
The only reason I can think of why this worn-out subject keeps popping
up is:
1. People who raise the question don't know how to do a
simple Google search.
2. They are very lonely individuals, without any friends, who
just sit at home in
front of their computers, longing for some sort.....any
sort of human interaction.
Let's move on............................
Roland F. Harriston, P.D.
mlerman@... wrote:
>
>
> I'm using 40 Vol, which I get at a Beauty Supply store. Best I can
> tell it's 12% H2O2, but that's very unclear. Anyway, using it 1:1 with
> muriatic acid (HCL) produces a very exothermic reaction that etches
> the board in just a few minutes, no heating and no bubbling.
>
> Since I am NOT a chemistry major, and since the fumes seem caustic to
> my uneducated smell, I always do the etching outside.
>
> Mark
>
> -----Original Message-----
> >From: Matthew Andrews <matt@... <mailto:matt%40slackers.net>>
> >Sent: Feb 28, 2011 7:01 PM
> >To: Homebrew_PCBs@yahoogroups.com
> <mailto:Homebrew_PCBs%40yahoogroups.com>
> >Subject: Re: [Homebrew_PCBs] Re: Question for the chemistry majors !!
> >
> > On 2/28/11 2:58 PM, Harvey White wrote:
> >>
> >>
> >> On Mon, 28 Feb 2011 09:34:35 -0800 (PST), you wrote:
> >>
> >> >Was looking at the MSDS for the 30% h2o2 .. yikes ..
> >> >This etching boards can be dangerous stuff .. lol
> >>
> >> It won't be as dangerous as you think. Use 30 VOL (produces 30 times
> >> more oxygen) H202, That's 3% Hydrogen Peroxide. You get it at
> >> drugstores and the like. NOT 30%.
> >>
> >Are you sure that's correct? this
> >site(http://www.using-hydrogen-peroxide.com/hairdressing-peroxide.html)
> >indicates that 30Vol is 9% and that the 3% you find in drug stores is
> 10V.
> >
> >Wikipedia also agrees with this, saying that 20-volume is equivalent to
> >1.667 mol/dm^3 or roughly 6%
> >
> >-Matt Andrews
> >
> >
> >>
> >> Harvey
> >>
> >> >
> >> >Randy
> >> >
> >> >
> >> >
> >> >
> >> >________________________________
> >> >From: jurod81 <jurod81@... <mailto:jurod81%40hotmail.com>
> <mailto:jurod81%40hotmail.com>>
> >> >To: Homebrew_PCBs@yahoogroups.com
> <mailto:Homebrew_PCBs%40yahoogroups.com>
> >> <mailto:Homebrew_PCBs%40yahoogroups.com>
> >> >Sent: Mon, February 28, 2011 11:03:38 AM
> >> >Subject: [Homebrew_PCBs] Re: Question for the chemistry majors !!
> >> >
> >> >
> >> >Hey Randy-
> >> >I will preface this with - I am not a chemistry major, but I do know
> >> a bit of
> >> >chemistry (more organic than inorganic).
> >> >To answer the original question: what the bubbles are that come off
> >> of the board
> >> >from peroxide + HCl etch, it is actually brings up an interesting
> bit of
> >> >chemistry. If you look at a oxidation-reduction table you will see
> >> that hydrogen
> >> >is below copper, so as a rule of thumb most Brønsted-Lowry acids such
> >> as HCl
> >> >cannot oxidize copper by themselves (nitric acid not included).
> >> Peroxides are a
> >> >little special; they are very unhappy molecules and easily decompose
> >> into
> >> >hydroxyl radicals on their way to becoming water. These hydroxyl
> >> radicals have
> >> >an oxidation potential close to fluorine and can easily attack copper
> >> metal
> >> >which has a full outer electron shell. The bottom line is that the
> >> gas given off
> >> >on the copper clad is oxygen (O2) and hydrogen (the final electron
> >> receptor in
> >> >the reaction), and I am sure that a bit of HCl off gassing since this
> >> is an
> >> >exothermic reaction. You end up with copper chloride as a final
> >> product. If you
> >> >want to practically speed up the reaction electrolysis is not going
> >> to help you
> >> >by very much, I would suggest either starting with a higher % of
> >> peroxide,
> >> >agitate your solution (with air bubbles or shaking) or warm you
> >> solution up a
> >> >bit.
> >> >
> >> >For those that are interested, Iron choride acts as a Lewis acid
> >> since Fe(III)
> >> >has a higher reduction potential then copper with will act as an
> >> electron
> >> >acceptor. The iron is reduce to Fe(II) and you end up with copper in
> >> solution.
> >> >Ammonium persulfate works on a similar free radical principle as the
> >> peroxide +
> >> >HCl principle, the only downsides are that it tends to be slower, you
> >> end up
> >> >with ammonia gas given off, and the persulfate decomposes rather
> >> quickly after
> >> >you add it to water meaning it is not very reusable (a day or two at
> >> the most
> >> >depending on how contaminated your starting water was).
> >> >You can reuse your etchant many times before tossing it (I recharge
> >> mine by
> >> >adding a bit more 30% peroxide). When you do toss it you can easily
> >> reclaim your
> >> >copper before dumping it down the sink since copper ions do very
> >> terrible things
> >> >to the environment (and your septic system's bacteria). You can
> >> neutralize the
> >> >acid by throwing some baking soda (Sodium bicarbonate) into the
> >> solution and the
> >> >peroxide by dumping some bread yeast which contains an enzyme called
> >> peroxidase
> >> >into the solution. You end up with a solution containing copper
> >> chloride and
> >> >sodium chloride in solution. Then you can run an electrolytic cell
> >> with copper
> >> >as the cathode (hooked up to the (-) terminal) and an inert carbon
> >> anode.
> >> >Chlorine will be given off at your anode and your cathode will grow
> >> some more
> >> >copper until the solution becomes depleted (then hydrogen bubbles
> >> will start
> >> >forming on it). Otherwise you may want to consider disposing of it as
> >> hazmat
> >> >when your county does one of those household hazardous material
> >> drop-off days.
> >> >My township does one every 6 months or so -- good for dropping off
> >> unused paint
> >> >etc.
> >> >-JRod
> >> >
> >> >BTW - Hydrogen and oxygen are a bad combination. All they need is a
> >> little heat
> >> >or a catalyst to get over the activation energy and you have fire.
> >> >
> >> >--- In Homebrew_PCBs@yahoogroups.com
> <mailto:Homebrew_PCBs%40yahoogroups.com>
> >> <mailto:Homebrew_PCBs%40yahoogroups.com>, "Randy S." <rj3819@...>
> wrote:
> >> >>
> >> >> I'm not talking about Chemistry.com here either ..lol
> >> >>
> >> >> Ok .. using muriatic acid .. with the hydrochloric acid in it mixed
> >> with
> >> >> peroxide.
> >> >>
> >> >> I looked a chemelec's website where he uses sulfuric acid and
> >> electrodes
> >> >> to remove over 90% of the copper, then finishes the board off in
> >> ferric
> >> >> chloride.
> >> >>
> >> >> So .. I thought if should work with other acids ..
> >> >> I put a electrode in on the negative lead and a scrape piece of
> >> board on the
> >> >> positive lead, started cranking up the voltage .. and it did indeed
> >> start
> >> >> drawing
> >> >> current and bubbling .. no ventilation so I shut it off right
> away ..
> >> >>
> >> >> The questions are :
> >> >> He mentioned gases from the electro-etch process, which makes
> sense as
> >> >> there are bubbles .. which are toxic .. I assume the gases from his
> >> acid would
> >> >> be different then the gases from mine. Chemistry majors ?? What is
> >> the gas
> >> >> being released from my H2O2 and HCLLOL
> >> >> Some kind of a hydrogen chloride gas ?? sounds toxic and flammable
> >> .. lol
> >> >>
> >> >> I was thinking I would make a setup to use my solution, aearate the
> >> tank and
> >> >> use some electro-etching, if that what it is , to help the process
> >> along ...
> >> >>
> >> >> Sound ok ? Would there be problems with that ?
> >> >>
> >> >> thanks all
> >> >>
> >> >> Randy - N2CUA
> >> >>
> >> >
> >> >
> >> >
> >> >
> >> >
> >> >
> >> >
> >> >[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]
> >
> >
> >
> >------------------------------------
> >
> >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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