[meteorite-list] RE: RE: Polishing slices?

From: Martin Altmann <Altmann_at_meteoritecentral.com>
Date: Mon Mar 21 13:24:54 2005
Message-ID: <009901c52376$5a973820$473c9a54_at_9y6y40j>

And addition:

Don't forget to clean your fingernails too, if you switch to the next higher
grid.
A single remaining grain from the coarser powder could disturb the result of
the next polishing round.
Control with a good magnyfying glass from time to time whether marks from
the antecedent coarser grains are visible,
if not anymore, you can go on to the next finest grain.
I use also the sand papers dry, but for cleaning the slices between the
switching to the next grid,
I use water or alcool for the more sensible stones.
If water, add a little drop of dish-liquid, and use a toothbrush from
downwards to the specimen - so the loose grindiding grains and the dust will
fall out and easily sink away from the piece. Dry it shortly.
This wet cleaning is not so problematic, if you continue immediately with
the grinding as the water will fastly volatilize.
After the last grinding a good test to see, whether there ist some dust left
in the slice is to wipe the surface with some pressure over your leg, which
should stuck in a black jeans. You'll see immediately whether it has some
dust left or not. But don't tell to mommy...

With dry polishing you should use a mask against fine dusts. Cosmic dust in
the lungs in not so agreeable, especially not the nickle from the iron
meteorites. Those masks aren't expensive and should be found in each DIY
store. Don't mix them up, with those for only hygienic purposes, those are
not suitable.

All in all a hard work, but by hand one can produce a perfect polish with
small means.

Happy working!
Martin

----- Original Message -----
From: "Christian Anger" <christian.anger_at_aon.at>
To: "'Meteoryt.net'" <marcin_at_meteoryt.net>;
<meteorite-list_at_meteoritecentral.com>
Sent: Tuesday, March 08, 2005 12:47 AM
Subject: [meteorite-list] RE: RE: Polishing slices?


> Disagreement !
>
> I also lay the sanding papers on a flat glass which has the same effect of
> producing a flat surface on the sample. I do not have rounded edges on my
> specimens.
> Also it is wrong to move the face of the probe in circles.
> You have to describe an "8" when moving the sample across the grains or
> paper - that's the real polishing technique.
>
> I also do NOT produce scratches. You have to take care not to withdraw
> grinding material from the coarser grinding papers to the next lower
> grinding grain size paper. Keep your sanding papers clean. Store every
> sanding paper extra, be careful and make the job with patience and love.
>
> I do not have the difficulties what Marcin is talking about.
> And diamond powders or pastes are expensive too.
>
> The technique I use only takes time. I own years of experience in
polishing
> by using sanding paper and I also use it DRY - without any fluid (water,
> alcohol etc...) - I think nobody expected this - but that's my experience
> and it works - works very well and I have best results - without any
> scratches. You just have to learn it. Experience is all.
>
> It is a lot of work, for sure, but this belongs to curating a collection
> too, for me, at least.
>
> Cheers and good night,
>
> Christian
>
Received on Mon 07 Mar 2005 07:32:47 PM PST