[meteorite-list] Hard to Polish Meteorites - Any Ideas? (diamond grit sandpaper?)

From: Michael Gilmer <*meteoritemike_at_meteoritecentral.com*> Date: Fri, 28 Oct 2011 18:20:45 -0400 Message-ID: <CAKBPJW-KX6qeHBgpZLnAKToWfExCBhad0Q0Uu5HCbP5Bf3qf+A_at_mail.gmail.com> · meteoritemike_at_meteoritecentral.com

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Galactic Stone & Ironworks - Meteorites & Amber (Michael Gilmer)
Website - http://www.galactic-stone.com
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On 10/28/11, Greg Hupe <gmhupe at centurylink.net> wrote:
> Hi Mike and All,
> I am out in the desert SW hunting and will be flying back home tomorrow
> afternoon. Seems the Count has answered a majority of the polishing tips I
> would have provided so I won't strain my eyes tapping on this tiny phone
> keypad. :)
>
> One of the greatest, and not so secret 'techniques', is hiring Marlin Cilz
> who does beyond fantastic for meteorites too large for my saw!
>
> Have fun!
>
> Best Regards,
> Greg Hupe
>
> On Oct 28, 2011, at 2:55 PM, Michael Gilmer <meteoritemike at gmail.com> wrote:
>
>> Hi Count and List,
>>
>> You are fortunate to work with Adam firsthand and watch him work his
>> magic.  It's no secret in the collector world that the Hupes do some
>> top-notch preparation work for all of their specimens.  When I
>> purchase a meteorite from Adam or Greg, I know I am getting some of
>> the best preparation available, even if the specimen is a small micro.
>> I wouldn't expect them to divulge their trade-secrets for
>> preparation, but I was hoping for a couple of pointers on how to
>> polish these hard to polish types.
>>
>> The responses I have received in public and private have been valuable
>> and I am very thankful for the advice.
>>
>> It seems part of my "problem" is dry sanding and part is the fact that
>> I don't have a lap-polisher.  I guess I could do some wet-sanding,
>> using distilled water, but I don't like introducing moisture into a
>> specimen unless it is absolutely necessary.  That is why the specimens
>> I prepare are stable and free of oxidation.  The only water my
>> specimens see is during cutting (which is unavoidable) and then they
>> go straight into a hot waiting oven for 6-10 hours to purge all
>> remaining water.  I use distilled water during cutting.  Once the
>> pieces are dry, I don't like getting them wet again.  But, I will try
>> some wet-sanding tonight and see how it goes.
>>
>> Does anyone know if/where I can purchase some diamond grit sandpaper
>> for hand-sanding?  I have been using the typical carbide sandpaper
>> from the local hardware store - 100, 200, 320, 400, 600.  I purchase
>> higher grits online because they are hard to find locally without
>> paying an arm and leg - 800, 1000, 1200, 1500.   But I don't recall
>> seeing any sandpaper with diamond-based grit.  I'd like to locate some
>> if I can.
>>
>> Right now I am polishing a gorgeous IMB meteorite for another dealer.
>> This meteorite takes a great polish, unlike the CR2 I am also
>> preparing.  I'll be busy polishing most of the night and my right-arm
>> will be tired to the point of fatigue.  I should have an incredible
>> Hulk right arm by now.  On the bright side of hand-polishing - I am
>> learning to use my left hand/arm to good effect, once my right side
>> tires out.  LOL
>>
>> Best regards,
>>
>> MikeG
>> --
>> ---------------------------------------------------------------------------------
>> Galactic Stone & Ironworks - Meteorites & Amber (Michael Gilmer)
>>
>> Website - http://www.galactic-stone.com
>> Facebook - http://tinyurl.com/42h79my
>> News Feed - http://www.galactic-stone.com/rss/126516
>> Twitter - http://twitter.com/galacticstone
>> ---------------------------------------------------------------------------------
>>
>>
>>
>> On 10/28/11, Count Deiro <countdeiro at earthlink.net> wrote:
>>> Hi Peter, Ed, Mike and List,
>>>
>>> I have spent a few days cutting and polishing dozens of various types
>>> with
>>> Adam Hupe'. With his guidance I set up my own shop with 6" and 8" saws
>>> and
>>> table and hand mounted polishing equipment. Basically, Adam uses quality
>>> diamond blades and arbor free polishing discs. Inspection cuts and slices
>>> are made with as fine a blade as will do the material in order to keep
>>> the
>>> kerf as thin as possible and reduce loss.. and at the same time eliminate
>>> the deep saw marks left by cheaper, thicker, blades.
>>>
>>> Polishing is accomplished with diamond impregnated discs both powered and
>>> in
>>> hand held blocks. He is a virtuoso with being able to turn our nice even,
>>> polished slices by hand. But, I never saw him dry cut or polish anything.
>>> He
>>> uses distilled water. This could be the secret, because when I used the
>>> same
>>> equipment dry, I couldn't get the same results until I added water for
>>> cooling and cleaning. The water also adds a fine abrasive sedimentary
>>> element to the polishing mix that I think is overlooked in it's ability
>>> to
>>> take up minute imperfections.
>>>
>>> Because of the fine (max.018) cut of his blades, I rarely found that I
>>> had
>>> to use coarser grained material to start polishing. Oh! Yes! It's really
>>> important to dress and clear the saw blade between cuts by running it
>>> through a piece of hand held common red brick. I could get by starting
>>> with
>>> 600 grit on small samples of friable material and move right into 1000
>>> and
>>> then go on up. Bigger, harder, meteorites, or where I may have gotten ham
>>> handed with the saw, required 300 to start. Remember these are diamond
>>> impregnated polishing discs and hand held blocks like the type used by
>>> masons to finish counter top granite and marble. They can be bought in
>>> sets
>>> on eBay. I learned from Adam how to hand hold specimens safely while
>>> cutting
>>> and polishing. We both agree that there is something to feeling the
>>> pressure
>>> through your fingers on the stone.
>>>
>>> All of this seems, I'm sure, very ordinary and it isn't rocket science,
>>> but
>>> the key info here is to use the best diamond abrasives and the smallest
>>> diameter blades... and work by hand...and use water to carry off the
>>> removed
>>> material from the surface. Dry them out in the oven and fine finish wit
>>> ultra fine jeweler's non-resin cloths.
>>>
>>> P.S. Watch out for Urelites...they eat polishing discs.
>>>
>>> Have fun,
>>>
>>> Count Deiro
>>> IMCA 3536
>>>
>>>
>>>
>>> -----Original Message-----
>>>> From: Michael Gilmer
>>>> Sent: Oct 28, 2011 9:34 A>Cc: meteorite-list at meteoritecentral.com
>>>> Subject: Re: [meteorite-list] Hard to Polish Meteorites - Any Ideas?
>>>>
>>>> Hi Peter, Ed, and List,
>>>>
>>>> I know that the Hupes have a powered lap-polisher that most likely
>>>> uses a diamond grit. I need to break down and buy a lap-polisher
>>>> (flat lap). But I typically don't sand enough material to warrant the
>>>> expense of a flat lap. Also, I enjoy hand-sanding and find it to be a
>>>> zen-like relaxation exercise when combined with the right music. :)
>>>>
>>>> But, every now and then I run across a meteorite that is stubborn and
>>>> won't take a polish. This is to be expected from friable types likes
>>>> LL6, most carbonaceous types, etc. But I know CR2 types are quite
>>>> hard and robust (also most CV3), so I expected this CR2 would be easy
>>>> to polish. Thus far, it has resisted my efforts to beautify it. It's
>>>> taking the polish, but the detail is becoming muddy and lost. I
>>>> thought it might be because I dry sand and powder from the sanding was
>>>> getting embedded in the matrix. So I tried giving the slice a quick
>>>> bath in alcohol, which removed most of the powder, but didn't improve
>>>> the appearance.
>>>>
>>>> I have some 1200 and 1500 grit sandpaper, and I tried going straight
>>>> to those (skipping 400-1000), but the result is the same - muddy
>>>> matrix and subdued chondrules.
>>>>
>>>> Best regards,
>>>>
>>>> MikeG
>>>> --
>>>> ---------------------------------------------------------------------------------
>>>> Galactic Stone & Ironworks - Meteorites & Amber (Michael Gilmer)
>>>>
>>>> Website - http://www.galactic-stone.com
>>>> Facebook - http://tinyurl.com/42h79my
>>>> News Feed - http://www.galactic-stone.com/rss/126516
>>>> Twitter - http://twitter.com/galacticstone
>>>> ---------------------------------------------------------------------------------
>>>>
>>>>
>>>>
>>>> On 10/28/11, Ed Deckert wrote:
>>>>> Hi Mike,
>>>>>
>>>>> Perhaps the Hup?'s "trade secret" is using diamond polishing media at a
>>>>> much
>>>>> higher/finer grit than you are using? It may be worth a try.
>>>>>
>>>>> Adam & Greg, can you share your secret?
>>>>>
>>>>> Ed
>>>>>
>>>>> ----- Original Message -----
>>>>> From: "Michael Gilmer"
>>>>> To:
>>>>> Sent: Friday, October 28, 2011 9:06 AM
>>>>> Subject: [meteorite-list] Hard to Polish Meteorites - Any Ideas?
>>>>>
>>>>>
>>>>>> Hi List,
>>>>>>
>>>>>> Some meteorites are hard to polish or just won't take a proper polish.
>>>>>> Allende is one example that comes to mind readily.
>>>>>>
>>>>>> I've got an endcut of NWA 801 CR2 that came from the Hupe Collection.
>>>>>> It has a wicked glossy polish on it that accentuates the chondrules.
>>>>>>
>>>>>> I'm working on some CR2 slices that need polishing and they won't take
>>>>>> a decent polish. I can get the saw marks out, but beyond that I can't
>>>>>> get a polish to take. The more I try, it just muddies up the matrix
>>>>>> and subdues the features. The metal fleck and rings around the
>>>>>> armored chondrules come out nicely, but the rest of the specimen
>>>>>> becomes muddy and the chondrules fade into the matrix. What am I
>>>>>> doing wrong? This particular CR2 is similar to NWA 801, but a little
>>>>>> more weathered. Could that have something to do with it?
>>>>>>
>>>>>> Do the Hupes have some magic trade-secret technique? Or am I
>>>>>> overlooking something obvious?
>>>>>>
>>>>>> I started out with 320 grit and then progressed to 400, 600, and 800
>>>>>> grit - hand sanding, dry, on wet/dry sandpaper.
>>>>>>
>>>>>> Best regards,
>>>>>>
>>>>>> MikeG
>>>>>>
>>>>>>
>>>>>> ---------------------------------------------------------------------------------
>>>>>> Galactic Stone & Ironworks - Meteorites & Amber (Michael Gilmer)
>>>>>>
>>>>>> Website - http://www.galactic-stone.com
>>>>>> Facebook - http://tinyurl.com/42h79my
>>>>>> News Feed - http://www.galactic-stone.com/rss/126516
>>>>>> Twitter - http://twitter.com/galacticstone
>>>>>> ---------------------------------------------------------------------------------
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