[meteorite-list] Etching solution

From: Steve Dunklee <steve.dunklee_at_meteoritecentral.com>
Date: Fri, 27 Jan 2012 18:59:37 -0800 (PST)
Message-ID: <1327719577.17713.YahooMailClassic_at_web121303.mail.ne1.yahoo.com>

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
> > >>>>
> > ______________________________________________
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> > >>>>
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> > >>>
> > >>>
> ______________________________________________
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Received on Fri 27 Jan 2012 09:59:37 PM PST