[meteorite-list] Water cutting question

From: MikeG <meteoritemike_at_meteoritecentral.com>
Date: Tue, 20 Nov 2012 18:57:21 -0500
Message-ID: <CAKBPJW8tkVJaT8PPMvGsRL3G2tc9aEPoBPCOwqNnt50u-8ueTA_at_mail.gmail.com>

Hi Folks,

I wanted to clarify that my personal experience is mostly with stony
types. While I do appreciate irons and pallasites, I avoid cutting
them. I've had a couple of near-misses while cutting irons. On one
particular occasion, I was attempting to cut a window into a small
Whitecourt iron. I was holding the specimen with my hands while
cutting, and it got stuck on the blade and hurled upwards. It nicked
the blade guard on the way up, narrowly missed my head, and ricocheted
off the garage ceiling. I found it about a week later, laying amongst
the clutter. It happened so fast that I had no time to react.

It was my fault and inexperience. Thankfully it didn't hit me in the face.

But back to distilled water : 90% of what I cut is stony meteorites.
Occasionally I will cut and polish some meso nuggets, but only if they
are small. I use distilled water on everything, but I have little
experience using it on irons. By the time I learned about distilled
water, I had all but quit cutting irons.

Best regards,

MikeG

-- 
-------------------------------------------------------------
Web - http://www.galactic-stone.com
Facebook - http://www.facebook.com/galacticstone
Twitter - http://twitter.com/GalacticStone
Pinterest - http://pinterest.com/galacticstone
RSS - http://www.galactic-stone.com/rss/126516
-------------------------------------------------------------
On 11/20/12, Michael Mulgrew <mikestang at gmail.com> wrote:
> Ed and list,
>
> I do not know of an exact way to calculate, but a few minutes at
> around 29 inches Hg of vacuum (sea level), especially on a hot plate
> and with a little aggitation, will remove about all of the dissolved
> gasses.
>
> Michael in so. Cal.
>
> On Tue, Nov 20, 2012 at 2:45 PM, Ed Deckert <edeckert at triad.rr.com> wrote:
>>
>> Hi Michael,
>>
>> Is there a method to calculate how long to leave a specific volume of
>> water
>> at a specific vacuum (inches Hg) to ensure that it is degassed?
>>
>> Thanks,
>> Ed
>>
>> ----- Original Message ----- From: "Michael Mulgrew"
>> <mikestang at gmail.com>
>> To: "Pete Pete" <rsvp321 at hotmail.com>
>> Cc: "meteoritelist meteoritelist" <meteorite-list at meteoritecentral.com>
>> Sent: Tuesday, November 20, 2012 5:08 PM
>> Subject: Re: [meteorite-list] Water cutting question
>>
>>
>>> Pete and list,
>>>
>>> Unfortunately the method you use does not effectively de-gas water, as
>>> exposure to the atmosphere will allow atmospheric gasses to continue
>>> to dissolve into solution; it is the atmospheric gasses that cause
>>> water to be corrosive.  To de-gas water you can:
>>>
>>> - Boil it
>>> - Sonicate under vacuum
>>> - Use a vacuum degasser
>>> - Bubble He through it
>>> - Etc.
>>>
>>> But unless you store your degassed water in an air-tight container
>>> gasses will begin to dissolve back into solution almost immediately.
>>>
>>> Michael in so. Cal.
>>>
>>> On Tue, Nov 20, 2012 at 1:47 PM, Pete Pete <rsvp321 at hotmail.com> wrote:
>>>>
>>>>
>>>> I do!
>>>>
>>>> I fill all my old distilled four litre jugs with tap water and let them
>>>> sit with the caps off for about seven days.
>>>> A chemist buddy of mine said it takes about 24 hours for any chlorine
>>>> and
>>>> other gasses to dissipate, but with the narrow neck and relatively small
>>>> cap
>>>> opening, to be prudent, after a couple of days I give it each jug a
>>>> shake
>>>> and leave it again for a few more.
>>>>
>>>> Cheers,
>>>> Pete
>>>>
>>>>> From: mikestang at gmail.com
>>>>> Date: Tue, 20 Nov 2012 11:17:37 -0800
>>>>> To: raremeteorites at yahoo.com
>>>>> CC: meteorite-list at meteoritecentral.com
>>>>> Subject: Re: [meteorite-list] Water cutting question
>>>>>
>>>>> Adam, Mike, Carl, and list:
>>>>>
>>>>>
>>>>> The main constituents in "pure" water that cause corrosion are
>>>>> dissolved gasses. Does anyone de-gas their cutting water?
>>>>>
>>>>> Michael in so. Cal.
>>>>>
>>>>> On Tue, Nov 20, 2012 at 10:43 AM, Adam Hupe <raremeteorites at yahoo.com>
>>>>> wrote:
>>>>> >
>>>>> >
>>>>> > Who knows what chemicals lurk in tap water? By purifying it, you are
>>>>> > >
>>>>> > removing the unknowns. I have
>>>>> > seen, for lack of a better term, Lawrencite disease creep up, >
>>>>> > especially with tap water that contains chlorine which seems to >
>>>>> > accelerate
>>>>> > the
>>>>> > problem. I have had no issues cutting with purified water as long as
>>>>> > the contact time has been minimized. I guess purifying it could make
>>>>> > the water more acidic but I also monitor the PH level and have not >
>>>>> > seen
>>>>> > much of a difference.
>>>>> >
>>>>> > Other alternative coolants such as mineral oil, pure ethyl alcohol
>>>>> > or
>>>>> > kerosine do not appeal to me anymore, mainly due to fumes, ignition
>>>>> > or
>>>>> > the smell left in the specimens.
>>>>> >
>>>>> >
>>>>> > Adam
>>>>> >
>>>>> >
>>>>> >
>>>>> >
>>>>> > ________________________________
>>>>> > From: Carl Agee <agee at unm.edu>
>>>>> > To: meteoritelist meteoritelist
>>>>> > <meteorite-list at meteoritecentral.com>
>>>>> > Sent: Tuesday, November 20, 2012 9:35 AM
>>>>> > Subject: [meteorite-list] Water cutting question
>>>>> >
>>>>> > I have been following the thread on cutting irons in water. My
>>>>> > question is, why distilled or purified water rather than tap water?
>>>>> > I
>>>>> > was under the impression that purified water, i.e. ultrapure water,
>>>>> > is
>>>>> > much more corrosive than mineralized water like spring water or tap
>>>>> > water. In fact, ultrapure water is so corrosive it is often used in
>>>>> > clean labs as a cleaning medium for surfaces. Also, the
>>>>> > pharmaceutical
>>>>> > industry no longer uses stainless steel tubing for ultrapure water
>>>>> > because of corrosion -- they use Teflon or polyethylene instead I
>>>>> > believe. Wouldn't pure water be worse on iron oxidation than
>>>>> > "mineral" water? I can understand using pure water to cut down on
>>>>> > trace element contamination for geochemical srtudies, especially on
>>>>> > stones, but I don't see how this helps for keeping irons from
>>>>> > rusting.
>>>>> > Also, while we are at it, what is the best blade for cutting irons?
>>>>> >
>>>>> > Thanks,
>>>>> >
>>>>> > Carl Agee
>>>>> > --
>>>>> > Carl B. Agee
>>>>> > Director and Curator, Institute of Meteoritics
>>>>> > Professor, Earth and Planetary Sciences
>>>>> > MSC03 2050
>>>>> > University of New Mexico
>>>>> > Albuquerque NM 87131-1126
>>>>> >
>>>>> > Tel: (505) 750-7172
>>>>> > Fax: (505) 277-3577
>>>>> > Email: agee at unm.edu
>>>>> > http://meteorite.unm.edu/people/carl_agee/
>>>>> > ______________________________________________
>>>>> >
>>>>> > Visit the Archives at http://www.meteorite-list-archives.com
>>>>> > Meteorite-list mailing list
>>>>> > Meteorite-list at meteoritecentral.com
>>>>> > http://six.pairlist.net/mailman/listinfo/meteorite-list
>>>>> > ______________________________________________
>>>>> >
>>>>> > Visit the Archives at http://www.meteorite-list-archives.com
>>>>> > Meteorite-list mailing list
>>>>> > Meteorite-list at meteoritecentral.com
>>>>> > http://six.pairlist.net/mailman/listinfo/meteorite-list
>>>>> ______________________________________________
>>>>>
>>>>> Visit the Archives at http://www.meteorite-list-archives.com
>>>>> Meteorite-list mailing list
>>>>> Meteorite-list at meteoritecentral.com
>>>>> http://six.pairlist.net/mailman/listinfo/meteorite-list
>>>
>>> ______________________________________________
>>>
>>> Visit the Archives at http://www.meteorite-list-archives.com
>>> Meteorite-list mailing list
>>> Meteorite-list at meteoritecentral.com
>>> http://six.pairlist.net/mailman/listinfo/meteorite-list
>>>
>>
> ______________________________________________
>
> Visit the Archives at http://www.meteorite-list-archives.com
> Meteorite-list mailing list
> Meteorite-list at meteoritecentral.com
> http://six.pairlist.net/mailman/listinfo/meteorite-list
>

Received on Tue 20 Nov 2012 06:57:21 PM PST