[meteorite-list] Etching solution msds ferric chloride

From: MexicoDoug <mexicodoug_at_meteoritecentral.com>
Date: Sat, 28 Jan 2012 02:12:54 -0500 (EST)
Message-ID: <8CEABA363A0DCE0-1584-A868_at_webmail-m151.sysops.aol.com>

Thanks for that MSDS Steve. So useful for the properties of ferric
chloride conveniently in your link.

One more thing to the discussion which IMO is constructive and useful
to anyone considering etching with some practical numbers but by no
means intended to be a manual sicne there are many variations that are
successful - the objective is simply to eat metal in a uniform and
contriolled manner ... But first a comment on the water in etchants:

Great all the info on these MSDSs...

for example, Steve's MSDS lists the composition of the Ferric Chloride
etchant:

9 % ferric chloride hexahydrate
91 % water

So this particular ferric chloride solution, quite a typical one, is
94.6% water!

It is low grade if you buy circuit board etchant complete with all the
unfiltered contaminants that are permissible and which can get into the
meteorite and contaminate it. It seems a bit much to me that so many
people worry about water getting in the meteorites with the nitric acid
procedure and for this reason demand pure alcohol, etc., and then some
other (or even the same) people etch with a solution that is 95% water
and don't think twice.

That is the reason I recommend a stock of 2 N to 3 N nitric acid which
is relatively mild and with, eg., a 50:50 dilution upon etching will
give something in the neighborhood of 6% on the low side if I remember
the math right just now, ignoring any (insignificant) density change.
If we go on the side of extra caution to avoid any potential criticism,
and have the patience and use the 2 N solution, a 50:50 w:w mix with
even pure ethanol might still result in around a nitric
acid:ethanol:water ratio of 6%:50%:44%. That's 44% water. If you used
50% ethanol (100 proof) you would be 69% water or so. Still well below
the 95% water used in FeCl3 etching.

On the other hand, even concentrated nitric acid mixed with pure 200
proof (100%) ethanol will yield a solution of a few percent water at
etching concentrations. I just don't see the benefit of worrying over
minimizing so much the water and making in favor of purehydroscopic
alcohol, since there is plenty of water around anyway. Perhaps someone
else has a good explanation, but I don't know it. No benefit that
three successive drying/alcohol bath cycles couldn't erase much better
anyway and when you consider the humidity in the atmosphere it all
becomes 'why bother?' for specimens that aren't hermetically sealed.

Then there is the suggestion of using dilute Nitric Acid alone, no
alcohol to deal with mixing and a 3 N stock solution is perfect to make
the range of concentrations you would want to etch. 3 N nitric is
probably something above 15% nitric acid, which means it is something
like 85% water. If you are used to this and have a procedure, you
could use this solution straight, however the best is probably a 50/50
dilution with water.

So the above are my recommendations spelled out. If anyone uses any
different concentrations with the straight acid it would be nice to
hear about. Solutions of 1.5 to 3.0 N nitric acid are much safer to
handle that muriatic acid and if it gets on you, a quick rinse is a
quick solution. The one major rule is to always wear eye protection.
I've had concentrate hydrochloric acid go into my eye from a splash as
a kid and there was no ill effect except on the nerves, but I suspect
Nitric acid is more risky in the eye. Visine eyedrops contain
hydrochloric acid I think, but nitric is another story if the burn scar
on my wrist from a lab accident is any indication, though that was
supercharged nitric acid, not the regular concentrated stuff in this
thread. The fuming nitric acid I made was in the 90% to 100% range,
bubbles like the movies mad scientist lab and is as scary as any
chemical possibly can be and it will eat flesh green upon contact.

Anyway, that gives somewhat a description of the dangers of
concentrated nitric acid and the relative mildness of the recommended
low concentrations. If you are extremely concerned you could drop it
down to 1 N, but I find that too slow for me unless I warm the
solution. There are a lot of trade offs going on behind the scenes. A
slow etch is usually more uniform, prettier, but there is more time for
something to go wrong, for some electrochemical reaction to discolor
the meteorite and for contaminants to enter the micro fissures,, get
around the inclusions, etc. That's why I'm on the higher side, and
that is also why FeCl3 is also so popular since it's usually formulated
for fast results. Plus at some point economy becomes important since
the difference in price between 1 N, 2 N and 3 N nitric acid prices is
not much and diluting these already pretty dilute acids is a piece of
cake vs. dealing with the concentrated stuff.

Hope that is helpful tio someone and if you have experience with
different temperatures / concentrations / ratios please post! If there
are any errors be kind to correct them as it is late ;-)

Kindest wisdhes
Doug






-----Original Message-----
From: Steve Dunklee <steve.dunklee at yahoo.com>
To: markig <markig at westnet.com>; Meteorite-list
<Meteorite-list at meteoritecentral.com>; MexicoDoug <mexicodoug at aim.com>
Sent: Fri, Jan 27, 2012 11:37 pm
Subject: Re: [meteorite-list] Etching solution msds ferric chloride



http://www.sciencelab.com/msds.php?msdsId=9925886

also may cause laurancite disease in irons or uncontrolled rusting


cheers
steve







--- On Sat, 1/28/12, Steve Dunklee <steve.dunklee at yahoo.com> wrote:

> From: Steve Dunklee <steve.dunklee at yahoo.com>
> Subject: Re: [meteorite-list] Etching solution
> To: markig at westnet.com, Meteorite-list at meteoritecentral.com,
"MexicoDoug"
<mexicodoug at aim.com>
> Date: Saturday, January 28, 2012, 2:59 AM
> http://multietch.com/
> cheers
>
>
> --- On Sat, 1/28/12, Steve Dunklee <steve.dunklee at yahoo.com>
> wrote:
>
> > From: Steve Dunklee <steve.dunklee at yahoo.com>
> > Subject: Re: [meteorite-list] Etching solution
> > To: markig at westnet.com,
> Meteorite-list at meteoritecentral.com,
> "MexicoDoug" <mexicodoug at aim.com>
> > Date: Saturday, January 28, 2012, 2:52 AM
> >? hi! cheers!
> > Steve Dunklee
> > http://www.sciencelab.com/msds.php?msdsId=9925886
> >
> >
> >
> >
> >
> >
> >
> >
> > --- On Sat, 1/28/12, MexicoDoug <mexicodoug at aim.com>
> > wrote:
> >
> > > From: MexicoDoug <mexicodoug at aim.com>
> > > Subject: Re: [meteorite-list] Etching solution
> > > To: markig at westnet.com,
> > Meteorite-list at meteoritecentral.com
> > > Date: Saturday, January 28, 2012, 12:46 AM
> > > Hi Mark,
> > >
> > > "Would appreciate a reference for the nickel
> chloride
> > being
> > > 15 times
> > > more carcinogenic than soluble nickel nitrate."
> > >
> > > That's not what I wrote although it could be true
> I
> > have no
> > > such reference to support the above.
> > >
> > > What I did write was:
> > >
> > > "Only Nickel chloride (a result of ferric
> chloride
> > etching)
> > > is carcinogenic at levels
> > > 15 times lower than those produced from nitric
> acid
> > > etching."
> > >
> > > There is a huge difference between what you
> understood
> > and
> > > what I actually wrote as threshhold toxicity
> levels
> > don't
> > > necessarily equate to activity factors.? This is
> > > because the body has dozens of competing
> homeostatic
> > > (metabolic, immune/allergic, etc.) processes that
> > relate to
> > > detoxification and an imbalance occurs when that
> one
> > single
> > > straw to many put on the camel breaks its back.
> > >
> > > The reference should be any MSDS (Material Safety
> Data
> > > Sheet), just check whichever one you have access
> to or
> > dig
> > > up first.
> > >
> > > Toxicology, especially when it comes to
> carcinogens is
> > so
> > > complex that I don't think anyone understands it,
> or
> > they
> > > would already gotten a billion buck grant from the
> NIH
> > by
> > > now.? It just comes in many small pieces.? I
> share
> > > your opinion that we should reference and I'm
> sorry if
> > I
> > > just dumped all this information for discussion,
> but it
> > was
> > > more useful that keeping i to myself.? I've not
> found
> > a
> > > reasonable layman's treatise anywhere on the
> subject so
> > I
> > > figured the met list was as good as it gets
> without
> > opening
> > > yet another research project to compete with the
> other
> > ones
> > > I've got floundering.
> > >
> > > Anyway, the exposure limits I mention I believe
> are for
> > lab
> > > rats approximating other mammals, like humans.?
> > Again,
> > > the more you get into this the more it's hard to
> > muzzle
> > > oneself becasue now we're getting further into
> it:
> > >
> > > so - must ask, can you breath it in (probably not
> in
> > most
> > > cases, but definiely cover your mouth, eyes, and
> any
> > other
> > > open oriface such as a wound when doing this.?
> That
> > > should be 'common knowledge' but really if doing
> it for
> > the
> > > first time, maybe not.
> > >
> > > and - must ask, so how permeable is the skin to it
> ...
> > > becasue if one has a 15X lower threshhold but is
> 15x
> > more
> > > difficult to uptake, then we'd have a wash.?
> Then
> > there
> > > are solubility issues, but these both look like
> they
> > are
> > > well soluble, just a glance at the MSDS will
> answer
> > that.
> > >
> > > last here, but definitely not any closure, is;
> what's
> > the
> > > significance of getting these things into ones
> local
> > > envoironment and the general environment (waters,
> > soils,
> > > air, etc.).? We don't think about this but doing
> it
> > out
> > > on the concrete patio outside of the kitchen and
> > tossing the
> > > waste into the immediate area, it will dry and
> become
> > > particulate contaminants which over time the wind
> will
> > > distribute in the lungs of little boys playing
> there,
> > > through the kitchen window, etc.? Probably no
> big
> > deal
> > > in most cases, but there is always that one case
> that
> > > something goes terribly wrong.? And getting back
> to
> > the
> > > maximum 'permissible' exposure limit (sheesh, now
> to
> > add
> > > residence time, cumulative properties in the body,
> it's
> > head
> > > spinning).
> > >
> > > Which is why, in this case for a rat which is
> assumed
> > to
> > > react as a human (but may not), at least we can
> point
> > a
> > > finger at the threshold of toxicity, which itself
> is a
> > a
> > > single point determined after half of the
> subjects
> > have
> > > croaked, illustrating that half are just fine
> whereas
> > it is
> > > toxic to half of them at even lower levels, or
> > something
> > > along tose lines.
> > >
> > > As for your other reference of isopropyl vs.
> ethyl
> > alcohols
> > > and explosion hazards, I'm sorry but perhaps
> someone
> > else
> > > has more time to develop this properly vs. this
> > informal
> > > discussion forum.? If I had time and a full lab,
> I
> > > would start by maing a ternary diagram of the two
> > alcohols
> > > and nitric acid, and plot the flash point of the
> > mixture for
> > > starters.? The information I saw was anecdotal
> and
> > not
> > > rigorous nor very quantitative.? However I don't
> > hacve
> > > time to spend on this subject any more due to
> personal
> > > circumstances and recommend that you try
> googling.?
> > > This is not a case of a proving beyond a
> reasonable
> > doubt
> > > that it is more explosive.? However there are
> enough
> > > warnings out there thaty would seem to suggest
> more
> > violent
> > > and higher incidence of isopropanol-HNO3 mixtures
> than
> > the
> > > EtOH analog, since we are talking about personal
> > > safety.? Clearly Isopropyl alcohol is similar
> > > inproperties relating to etching that given the
> more
> > > widespread use in general metallurgy of EtOH, it's
> the
> > devil
> > > we know better
> > >
> > > I'm convinced of the Isopropanol/ethanol issue all
> I
> > need to
> > > be more vigilant.? But that doesn't mean I
> wouldn't
> > use
> > > it if there was some reason to do that.? Rather
> than
> > > obsessing too much over a terribly complex issue
> and
> > coming
> > > to the same inconclusion, I'd just make simple,
> yet
> > > effective modifications to my procedure -
> > > Why deal with comncentrated nitric in a home
> > environment at
> > > all?? How silly!? You (general) want to save a
> few
> > > pennies at your own risk, pennywise --- just have
> the
> > > Hazardous Materials emergency number handy.?
> > Otherwise
> > > buy the diluted acid= problem significantly
> > minimized.?
> > > You want to make etchant?? Don't make such a
> large
> > > amount in a bottle/beaker at once.? Don't use
> such an
> > > excess when etching, experiment by painting it on
> with
> > a
> > > brush instead - problem significantly minimuzed
> ... and
> > so
> > > on.
> > >
> > > Hope this gives better insight.? Having THE
> answer to
> > > these things is too tall an order, yet experience
> and
> > common
> > > sense are why other individuals can etch more
> easily
> > than
> > > making scrambled eggs.? Our appreciation of risk
> is
> > > terribly distorted.? Once I was in a discussion
> with
> > > Sterling sopmewhere discussing this and he even
> > referenced
> > > someplace, proabbly wiki the bias I described had
> a
> > > name.? You know, the same one that evaluates
> whether
> > to
> > > be frightened from falling asteroids vs. driving
> to
> > work in
> > > the morning.? I'm still waiting for the thriller
> > movie,
> > > "Highway jaunt" where no rogue asteroids or
> murderous
> > > psychopats pass by, but Strawberry Shortcake girl
> just
> > takes
> > > her car for a spin and suddenly every individual
> in
> > the
> > > traffic stream has a compulsion to run over her on
> her
> > sweet
> > > bicycle.? Point of the dumb example being the
> high
> > risk
> > > we have experience has much lower fear factor than
> the
> > > almost non-existent risk which ends in carnage
> and
> > mahem,
> > > even if a decision tree analysis shows that the
> > friendly
> > > risk is a million times more likely.
> > >
> > > Kindest wsihes
> > > Doug
> > >
> > > PS I have stretched too much to participate in
> this
> > give
> > > some other difficult responsibilities I ahve at
> the
> > m,oment
> > > so I did my best and will likely retire for a
> while to
> > catch
> > > up on things.
> > >
> > > PPS, After all this, I think my new etchant of
> choice
> > will
> > > be Coca Cola.? No doubt it works or can be
> tweaked
> > to,
> > > too.
> > >
> > >
> > >
> > > -----Original Message-----
> > > From: Mark Grossman <markig at westnet.com>
> > > To: nf114ec <nf114ec at npgcable.com>;
> > > meteorite-list <meteorite-list at meteoritecentral.com>;
> > > MexicoDoug <mexicodoug at aim.com>
> > > Sent: Fri, Jan 27, 2012 6:20 pm
> > > Subject: Re: [meteorite-list] Etching solution
> > >
> > >
> > > Hi,
> > >
> > > Couple of thoughts.
> > >
> > > Mark's Law:
> > >
> > > If you're standing in the exact same spot as
> someone
> > else
> > > when a mixture of
> > > nitric acid and ethanol explodes, the
> sensitivities of
> > the
> > > two individuals
> > > to harm are always the same. :-)
> > >
> > > Both nickel chloride and nickel nitrate are
> soluble
> > nickel
> > > compounds, and as
> > > far as carcinogenicity goes, the American
> Conference
> > of
> > > Governmental
> > > Industrial Hygienists and the International Agency
> for
> > > Research on Cancer
> > > group the two compounds together.? As far as I
> am
> > > aware, there was no
> > > singling out of nickel chloride as being 15 times
> more
> > > carcinogenic than
> > > nickel nitrate - you indicated both are products
> of
> > etching
> > > - one from
> > > ferric chloride and the other from nitric acid.?
> The
> > > insoluble oxides of
> > > nickel are more carcinogenic, but that's not the
> > compounds
> > > you are referring
> > > to.? Would appreciate a reference for the nickel
> > > chloride being 15 times
> > > more carcinogenic than soluble nickel nitrate.
> > >
> > > Similarly, would appreciate a reference to
> isopropyl
> > alcohol
> > > being more
> > > dangerous to use for etching with nitric acid
> than
> > ethanol,
> > > under the same
> > > set of conditions.? Why is isopropyl alcohol
> more
> > prone
> > > to a "freak"
> > > explosion or "blow up" than ethanol?? Explosions
> with
> > > concentrated nitric
> > > acid and ethanol are well-documented.
> > >
> > > Now I am not relying on Wikipedia as an academic
> > reference,
> > > but I think the
> > > information contained on the webpage is worthy of
> > discussion
> > > and/or
> > > criticism.? See http://en.wikipedia.org/wiki/Nital and the
mention of
> > > the
> > > hazards associated with 5 and 10 percent
> solutions.?
> > > This information
> > > appears to come from Bretherick, which is a
> pretty
> > good
> > > chemical reference
> > > that I have used in the past (see
> > > http://www.ab.ust.hk/hseo/tips/ls/ls005.htm).
> > >
> > > Reading Material Safety Data Sheets should always
> be
> > > required - but realize
> > > that many are inadequate and often do not list or
> spell
> > out
> > > the safety
> > > precautions which should be employed.
> > >
> > > A lot of technical information was contained in
> the
> > last few
> > > emails, and if
> > > we all agree that respect for chemicals is
> critical,
> > then it
> > > would be useful
> > > to confirm the facts.
> > >
> > > Thanks!
> > >
> > > Mark
> > >
> > > Mark Grossman
> > > Meteorite Manuscripts
> > >
> > >
> > > ----- Original Message -----
> > > From: "MexicoDoug" <mexicodoug at aim.com>
> > > To: <nf114ec at npgcable.com>;
> > > <meteorite-list at meteoritecentral.com>
> > > Sent: Friday, January 27, 2012 1:02 PM
> > > Subject: Re: [meteorite-list] Etching solution
> > >
> > >
> > > > Hi Jim,
> > > >
> > > > My respects to all the ferric chloride lovers
> out
> > there
> > > and
> > > especially Ron
> > > > Hartman, bless him.? A blanket statement of
> a
> > > "better etch" is pretty
> > > > meaningless.? I recall asking Arcady who had
> all
> > > the Seymchan several
> > > > years back why all of his specimens were
> etched
> > so
> > > deeply that they
> > > looked
> > > > like someone chiseled the etch into them and
> then
> > put
> > > on a matte
> > > > clearcoat.? He said, the customers prefer a
> deep
> > > etch.? I thought it
> > > was
> > > > butt ugly (not to mention a more discrete
> etching
> > such
> > > as by mild
> > > nitric
> > > > acid's slow action introduces far less
> nucleation
> > sites
> > > for
> > > oxidation).
> > > > There are so many factors.
> > > >
> > > > If the iron chloride etch were better it
> wouldn't
> > hurt
> > > to send those
> > > > conclusions to the Smithsonian, British
> Museum,
> > Weiner
> > >
> > > Naturhistorisches
> > > > Museum, Max-Planck-Institut f?r Chemie (or
> > whatever
> > > its called now)
> > > > Collection, Paris Mus?um National
> d'Histoire
> > > Naturelle, etc. for
> > > comment.
> > > > ;-)
> > > >
> > > > BTW, there are many variables not realated to
> the
> > etch
> > > to consider.
> > > > Though ferric chloride is 'easier', when it
> comes
> > to
> > > mixing up, it
> > > doesn't
> > > > mean it is less toxic in other ways.? Ever
> > wonder
> > > if it was legal or
> > > smart
> > > > to pour spent solution down the drain or into
> the
> > > soils? Nickel
> > > chloride
> > > > and nickel nitrate (produced in etching) are
> both
> > > mutagenic.? Only
> > > Nickel
> > > > chloride (a result of ferric chloride
> etching) is
> > > carcinogenic at
> > > levels
> > > > 15 times lower than those produced from
> nitric
> > acid
> > > etching.? But
> > > with all
> > > > the other heavy metal ions in iron
> meteorites,
> > again,
> > > respect for the
> > > > chemical is important regardless of what
> risks
> > are
> > > perceived - it's
> > > never
> > > > the full story and like smoking, everyone
> doesn't
> > even
> > > have equal
> > > > sensitivity.
> > > >
> > > > Kindest wishes
> > > > Douh
> > > >
> > > >
> > > > -----Original Message-----
> > > > From: Jim Wooddell <nf114ec at npgcable.com>
> > > > To: Meteorite-List <meteorite-list at meteoritecentral.com>
> > > > Sent: Fri, Jan 27, 2012 6:48 am
> > > > Subject: Re: [meteorite-list] Etching
> solution
> > > >
> > > >
> > > > I believe there was an article by Hartman a
> few
> > years
> > > back about the
> > > use
> > > > of
> > > > ferric chloride.? The conclusion was that
> it
> > gave
> > > a better etch???? I
> > > > think
> > > > it was in Meteorite-Times.
> > > >
> > > > Jim
> > > >
> > > >
> > > >
> > > > Jim Wooddell
> > > > http://k7wfr
> > > >
> > > > ----- Original Message -----
> > > > From: "MexicoDoug" <mexicodoug at aim.com>
> > > > To: <mexicodoug at aim.com>;
> > > <markig at westnet.com>;
> > > > <meteoritesnorth at hotmail.ca>;
> > > <meteorite-list at meteoritecentral.com>
> > > > Sent: Friday, January 27, 2012 1:49 AM
> > > > Subject: Re: [meteorite-list] Etching
> solution
> > > >
> > > >
> > > >> "Besides water, I'm suspecting Nitric +
> > acetone
> > > (Nitkeytone ?) and
> > > > any
> > > >> number of other solvents would work"
> > > >>
> > > >> OK, don'rt bother with this one!? I
> just
> > did;
> > > It actually etches, but
> > > >> leaves a yucky finish.? The fumes are
> no
> > worse
> > > than other nitals,
> > > > though I
> > > >> wouldn't want to breath much of them
> until I
> > knew
> > > more; but there
> > > > didn't
> > > >> seem to be any decomposition.? I used
> > reagent
> > > grade acetone to avoid
> > > >> possibly nasty impurities, and the
> nitric
> > acid
> > > concentration only
> > > > 3.9%
> > > >> just in case I hit a flash point, full
> face
> > shield
> > > and a fan venting
> > > > right
> > > >> out the door.? Nice to have had an 81 F
> day
> > > today and still its warm
> > > >> enough to open the door ;-) nice etch,
> > terrible
> > > residue.
> > > >>
> > > >> Kindest wishes
> > > >> Doug
> > > >>
> > > >>
> > > >>
> > > >> -----Original Message-----
> > > >> From: MexicoDoug <mexicodoug at aim.com>
> > > >> To: markig <markig at westnet.com>;
> > > meteoritesnorth
> > > >> <meteoritesnorth at hotmail.ca>;
> > > meteorite-list
> > > >> <meteorite-list at meteoritecentral.com>
> > > >> Sent: Fri, Jan 27, 2012 3:11 am
> > > >> Subject: Re: [meteorite-list] Etching
> > solution
> > > >>
> > > >>
> > > >> "explosive"
> > > >>
> > > >> Definitely caution when playing around
> with
> > > corrosives is of the
> > > first
> > > >> order...that said,
> > > >>
> > > >> sure, ethanol is a racing car engine fuel
> and
> > under
> > > the right
> > > >> conditions can combust; But people drink
> it
> > even
> > > straight...
> > > >>
> > > >> Many things we do have risks associated
> with
> > them
> > > some very serious
> > > > and
> > > >> definitely we must respect all reagents
> > especially
> > > corrosives like
> > > >> nitric acid.? For example, many people
> enjoy
> > > fireworks.? Yet,
> > > > fireworks
> > > >> are explosive and dangerous if you put
> them
> > near
> > > sparks or heat,or
> > > try
> > > >> to light them with a charcoal grill.?
> And
> > > obviously gasoline combusts
> > > >> too yet mechanics and Dads everywhere use
> it
> > to
> > > clean hands and metal
> > > >> parts and also have arc welders nearby.?
> Or
> > > sulfuric acid inside a
> > > car
> > > >> battery - don't get it on your bikini
> when
> > working
> > > on the car!? If
> > > you
> > > >> are going to use anything, it needs to be
> done
> > with
> > > respect and a
> > > > quick
> > > >> read of the MSDS of whatever chemicals
> you
> > are
> > > using... (and don't
> > > >> trust everything you read on a
> discussion
> > l;ist
> > > posted at 3 AM)
> > > >>
> > > >> It is not a good idea to have
> concentrated
> > nitric
> > > acid and ignore the
> > > >> label, for example and my heart goes out
> to
> > Anita
> > > on that.? Depends
> > > > the
> > > >> kind of person you are.? When I make my
> > > smoothie in the morning I use
> > > >> fresh cherries as one of 18-20
> ingredients and
> > a
> > > preparation that
> > > > takes
> > > >> an hour.? It's life threatening if I
> > > accidentally put a pit in my
> > > >> blender (which can easily liquify
> meteorites,
> > it's
> > > so powerful) due
> > > to
> > > >> the specialized needs of a family member
> who
> > cannot
> > > eat.? So I double
> > > >> count the cherries first, count the pits
> as I
> > punch
> > > them out, and
> > > then
> > > >> count them once again when I dispose of
> > them.?
> > > No shortcuts, All
> > > > common
> > > >> sense!
> > > >>
> > > >> Bart Simpson's pet python once made nital
> in
> > an
> > > episode of The
> > > >> Simpsons, which is amusing if you haven't
> had
> > a bad
> > > experience you
> > > >> can't laugh about.... I think the
> writers
> > were
> > > Caltech rejects that
> > > > had
> > > >> to go to MIT and have to do this to
> humor
> > > themselves, this wasn't the
> > > >> only snarky chemistry episode.
> > > >>
> > > >> (episode: Stop or my Dog will Shoot!)
> > > >>
> > > >> Here's the link:
> > > >>
> > > >> http://video.i.ua/user/810302/8185/35583/
> > > >>
> > > >> it take a little time to stream, but
> once
> > ready the
> > > scene is at the
> > > >> 17:49 minute:seconds mark.
> > > >>
> > > >> ... and that' why in my summary which I
> did
> > much
> > > too quickly to be
> > > >> complete, I suggest that you use water,
> that
> > is to
> > > say, NitH20,. or
> > > as
> > > >> it's commonly known just dilute Nitric
> Acid,
> > rather
> > > tha alcohols to
> > > >> develop your method.? Nothing wrong
> with
> > > water, it is really getting
> > > a
> > > >> bum wrap and it is GRAS ;-)? It is what
> > > everyone that is using FeCl3
> > > > is
> > > >> using as a diluent, too.? For the HNO3
> the
> > 3.0
> > > N concentration works
> > > >> best for me.? Absolutely no need to buy
> > > concentrated acid and you can
> > > >> avoid all the issues of what to add to
> what
> > and no
> > > need for Hazmet
> > > >> backup.? You can buy it already diluted,
> get
> > > the same benefit of a
> > > >> nitric acid etch (alcohol doesn't etch,
> it's
> > only a
> > > carrier and
> > > >> diluent).? Just crank up the oven to
> the
> > > higher end of a safe drying
> > > >> temperature.? That's the only real
> benefit
> > of
> > > alcohol in my opinion -
> > > >> it allows a cooler drying which can
> povide a
> > nicer
> > > (lower oxdation
> > > >> residue on the virgin etched surface, but
> now
> > we
> > > are staerting rally
> > > > to
> > > >> split hairs...IMO.
> > > >>
> > > >> Speaking of diluents, there's no reason
> nital
> > > (alcohol) is special as
> > > > a
> > > >> diluent.? Besides water, I'm suspecting
> > Nitric
> > > + acetone (Nitkeytone
> > > > ?)
> > > >> and any number of other solvents would
> work
> > fine if
> > > not be hiding a
> > > >> secret for even a better etching
> solution.?
> > > Sure acetone is flammable
> > > >> and can give you the willies too, you
> can't
> > win but
> > > that doesn't stop
> > > >> women who understand the chemical they
> use
> > from
> > > putting it on their
> > > >> fingernails ;-) granted not with acid,
> though
> > I bet
> > > some do
> > > >> inadvertantly mix it with salycilic acid
> > solution
> > > when disolving
> > > > excess
> > > >> skin ;-), which if not used properly
> could
> > > chemically remove a lot of
> > > >> flesh ...
> > > >> Kindest wishes
> > > >> Doug
> > > >>
> > > >>
> > > >> -----Original Message-----
> > > >> From: Mark Grossman <markig at westnet.com>
> > > >> To: MexicoDoug <MexicoDoug at aim.com>;
> > > meteoritesnorth
> > > >> <meteoritesnorth at hotmail.ca>;
> > > meteorite-list
> > > >> <meteorite-list at meteoritecentral.com>
> > > >> Sent: Fri, Jan 27, 2012 12:32 am
> > > >> Subject: Fw: [meteorite-list] Etching
> > solution
> > > >>
> > > >>
> > > >> Did a quick search on the internet.?
> Read
> > this
> > > tale from the
> > > Meteorite
> > > >> Association of Georgia regarding the
> hazards
> > of
> > > mixing nitric acid
> > > and
> > > >> ethanol:
> > > >>
http://www.meteoriteassociationofgeorgia.org/article-052007.htm.
> > > >>
> > > >> Mark
> > > >>
> > > >> Mark Grossman
> > > >> Meteorite Manuscripts
> > > >>
> > > >>
> > > >> ----- Original Message -----
> > > >> From: "Mark Grossman" <markig at westnet.com>
> > > >> To: <mexicodoug at aim.com>;
> > > <meteoritesnorth at hotmail.ca>;
> > > >> <Meteorite-list at meteoritecentral.com>
> > > >> Sent: Thursday, January 26, 2012 11:40
> PM
> > > >> Subject: Re: [meteorite-list] Etching
> > solution
> > > >>
> > > >>
> > > >>> I don't know all of the details of
> the
> > etching
> > > process, but a word of
> > > >>> caution - mixing concentrated nitric
> acid
> > with
> > > ethanol can result in
> > > >> an
> > > >>> explosion and a fire.? I've
> witnessed
> > the
> > > results of the reaction
> > > when
> > > >>> someone inadvertently mixed the two
> in a
> > lab
> > > years ago.
> > > >>>
> > > >>> Mark
> > > >>>
> > > >>> Mark Grossman
> > > >>> Meteorite Manuscripts
> > > >>>
> > > >>> ----- Original Message -----
> > > >>> From: "MexicoDoug" <mexicodoug at aim.com>
> > > >>> To: <mexicodoug at aim.com>;
> > > <meteoritesnorth at hotmail.ca>;
> > > >>> <Meteorite-list at meteoritecentral.com>
> > > >>> Sent: Thursday, January 26, 2012
> 11:23 PM
> > > >>> Subject: Re: [meteorite-list]
> Etching
> > solution
> > > >>>
> > > >>>
> > > >>>> PS - if you don't have a hood or
> > other
> > > exhaust, the methyl alcohol
> > > >> could
> > > >>>> also be dangerous becasue the
> liver
> > breaks
> > > it down into toxins and
> > > >> you
> > > >>>> will inhale some of it.? That's
> > > another reason why I use ethanol in
> > > >> the
> > > >>>> oven, and frankly much more
> important
> > a
> > > reason than saving a few
> > > >> pennies
> > > >>>> ;-)? You can consider the
> residence
> > > time of the toxins in your
> > > >> system to
> > > >>>> be as long as a week, so if your
> are
> > doing
> > > etxching all day
> > > long,and
> > > >> are
> > > >>>> using methanol nital you
> definitely
> > need a
> > > very well ventilated
> > > >> place,
> > > >>>> and methanol is sneaky worthy of
> a
> > CSI
> > > episode of an innocent who
> > > >> done it
> > > >>>> since the syptoms and critical
> second
> > hit
> > > can be stealth and barely
> > > >>>> naseaous for the first.
> > > >>>>
> > > >>>> I know you didn't ask about
> methyl
> > alcohol,
> > > but its good to see the
> > > >> 4
> > > >>>> common solcvent
> benefits/liabilities
> > side
> > > by side, at least my take
> > > >> on
> > > >>>> it. Anyway, you can see why
> ethyl
> > alcohol
> > > iis usually preferred.? I
> > > >> just
> > > >>>> checkethe azeotrophes
> andisopropyl is
> > only
> > > 2.3 C above ethanol
> > > >> mixtures
> > > >>>> so its ability to remove water
> would
> > be
> > > very similar in the oven,
> > > >> the
> > > >>>> last thing to look up to decide
> > > theoretically approximating the
> > > >>>> penetrating ability as related to
> the
> > > surface tension of the
> > > alcohol
> > > >>>> (just a guess) what is the
> bestest
> > alcohol
> > > would be to check the
> > > >> surface
> > > >>>> tension.? I just did and all
> three
> > > alcohols are nearly 4 times that
> > > >> of
> > > >>>> water and within 5% o each other,
> so
> > I
> > > would think that on
> > > >> penetrating
> > > >>>> ability they are probably all
> tied
> > and
> > > would argue all factors
> > > >> considered
> > > >>>> ethanol is best since the worst
> you
> > get is
> > > a standard hangover in
> > > >>>> standard use conditions, and to
> get a
> > freak
> > > explosion from EtOH
> > > >> mixtures
> > > >>>> with acid is minimal compared to
> > > isopropyl.
> > > >>>>
> > > >>>> Ferric chloride of course doesn't
> have
> > the
> > > toxicity not
> > > >> flammability, but
> > > >>>> it stains like heck and with
> proper
> > respect
> > > for the reagents plus a
> > > >>>> little experience, like
> everything
> > else the
> > > risks are minimized.
> > > >> That's
> > > >>>> another reason to start with
> dilute
> > nitric
> > > which I highly recommend
> > > >> until
> > > >>>> you have the bugs worked out of
> the
> > etching
> > > "assembly line", ie,
> > > >> method
> > > >>>> you find best for your work.
> > > >>>>
> > > >>>> Good luck,
> > > >>>>
> > > >>>> Kindest wshes
> > > >>>> Doug.
> > > >>>>
> > > >>>>
> > > >>>> -----Original Message-----
> > > >>>> From: MexicoDoug <mexicodoug at aim.com>
> > > >>>> To: meteoritesnorth <meteoritesnorth at hotmail.ca>;
> > > Meteorite-list
> > > >>>> <Meteorite-list at meteoritecentral.com>
> > > >>>> Sent: Thu, Jan 26, 2012 10:30 pm
> > > >>>> Subject: Re: [meteorite-list]
> Etching
> > > solution
> > > >>>>
> > > >>>>
> > > >>>> Craig,
> > > >>>> Let me add (the message actually
> got
> > away
> > > before being finished as
> > > I
> > > >>>> write piecemeal and then send)
> that as
> > far
> > > as etching it works
> > > fine,
> > > >>>> but if you look at the series of
> > alcohols,
> > > methyl (bp = 65 C),
> > > ethyl
> > > >>>> (bp = 78 C) and isoproply alcohol
> (bp
> > = 83
> > > C), methyl alcohol
> > > >>>> (methanol) is by far the safest
> until
> > you
> > > get a lot of experience
> > > >>>> working with these under a
> hood.?
> > > "Ethyl nital" is mildly flammable
> > > >> in
> > > >>>> and Isopropyl nital is pretty
> > dangerous
> > > since if can blow up in
> > > >> certain
> > > >>>> conditions that aren't difficult
> to
> > > arrange.? Nothing to do with
> > > the
> > > >>>> etching results which are left
> to
> > trial and
> > > error, but rather the
> > > >>>> safety which I should have
> mentioned.
> > > >>>>
> > > >>>> While all the alcohols work fine,
> keep
> > in
> > > mind two of the factors
> > > > you
> > > >>>> are working with are
> > miscibility/penetrant
> > > ability and vapor
> > > >> pressure.
> > > >>>> Vapor pressure you can estimate
> by
> > boiling
> > > point - lower bp is a
> > > >> higher
> > > >>>> vp.? The higher vp the quicker
> it
> > will
> > > evaporate out, so methanol
> > > >> would
> > > >>>> seem to have the advantage,
> thought
> > it
> > > might form some azeotropes
> > > > and
> > > >>>> stay in longer, as could the
> rest
> > without
> > > looking this up (no time
> > > > at
> > > >>>> the moment).
> > > >>>>
> > > >>>> To the series of three common
> alcohols
> > you
> > > could just add water bp
> > > =
> > > >>>> 100 and consider it almost as a
> > continuim
> > > and play with the you
> > > like
> > > >>>> which will influence drying time
> > among
> > > other important parameters.
> > > > I
> > > >>>> use methanol and later rinse
> with
> > ethanol
> > > (cheaper for me), which
> > > is
> > > >>>> the reverse of good drying
> practice I
> > would
> > > think, but half of the
> > > >> time
> > > >>>> I just use the diluted acid at 2
> - 3
> > N.
> > > >>>>
> > > >>>> Hope that was a better answer,
> sorry
> > for
> > > not finishing the first
> > > >>>> kindest wishes
> > > >>>> Doug
> > > >>>>
> > > >>>>
> > > >>>> -----Original Message-----
> > > >>>> From: Craig Moody <meteoritesnorth at hotmail.ca>
> > > >>>> To: mexicodoug <mexicodoug at aim.com>
> > > >>>> Sent: Thu, Jan 26, 2012 9:42 pm
> > > >>>> Subject: RE: [meteorite-list]
> Etching
> > > solution
> > > >>>>
> > > >>>>
> > > >>>> Much appreciated Doug, Thank
> you!? I
> > > have lots of 99% around.
> > > >>>>
> > > >>>> Craig
> > > >>>>
> > > ______________________________________________
> > > >>>>
> > > >>>> Visit the Archives at
> > > >>>> http://www.meteoritecentral.com/mailing-list-archives.html
> > > >>>> Meteorite-list mailing list
> > > >>>> Meteorite-list at meteoritecentral.com
> > > >>>> http://six.pairlist.net/mailman/listinfo/meteorite-list
> > > >>>>
> > > >>>>
> > > ______________________________________________
> > > >>>>
> > > >>>> Visit the Archives at
> > > >>>> http://www.meteoritecentral.com/mailing-list-archives.html
> > > >>>> Meteorite-list mailing list
> > > >>>> Meteorite-list at meteoritecentral.com
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> > > >>>
> > > >>>
> > ______________________________________________
> > > >>>
> > > >>> Visit the Archives at
> > > >>> http://www.meteoritecentral.com/mailing-list-archives.html
> > > >>> Meteorite-list mailing list
> > > >>> Meteorite-list at meteoritecentral.com
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> > > >>
> > > >>
> > > >>
> > ______________________________________________
> > > >>
> > > >> Visit the Archives at
> > > >> http://www.meteoritecentral.com/mailing-list-archives.html
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> > > >>
> > > >>
> > ______________________________________________
> > > >>
> > > >> Visit the Archives at
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> > > >
> > > >
> ______________________________________________
> > > >
> > > > Visit the Archives at
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> > > >
> > > >
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> > > >
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> > > >
> > >
> > >
> > > ______________________________________________
> > >
> > > Visit the Archives at
http://www.meteoritecentral.com/mailing-list-archives.html
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> >
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Received on Sat 28 Jan 2012 02:12:54 AM PST