[meteorite-list] Etching solution

From: Jim Wooddell <nf114ec_at_meteoritecentral.com>
Date: Fri, 27 Jan 2012 04:31:42 -0700
Message-ID: <DD9457BEF0D5434CA6C864BE5801F298_at_Grande>

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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Received on Fri 27 Jan 2012 06:31:42 AM PST