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 Post subject: Pre polishing CZ discussion.
PostPosted: Sat Dec 07, 2019 6:22 am 
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Recently I started cutting my first CZ. I have finished about 20 gems so far. I am fairly comfortable with my machine, laps, charging, transferring ect.

-I roughed the CZ down with 260 grit.
-preformed it out roughly with 600 grit.
-cut the facets down with 1200 grit.
-I am pre polishing with 8000 on a zinc lap.
-polishing with 60000 on batt lap.

I am very satisfied with the trial pre polishing quality and the polishing quality.

my question comes in with how long it is taking to get a perfect pre polish PER facet. I use a Facetron ( love it BTW ) on speed setting 3 and it takes about... 75 sweeps across the lap PER facet!! to eliminate all the scores and fly poop looking specs. This lap seems to be well charged as a garnet only takes about 10 sweeps per facet to pre polish.

Is 75 sweeps per facet on CZ normal to get a perfect pre polish?

for pressure on the stone I would saying am applying about... double the pressure you would if you were holding a pencil and writing your name. Thanks in advance for any input.


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 Post subject: Re: Pre polishing CZ discussion.
PostPosted: Mon Jan 06, 2020 1:48 pm 
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Joined: Thu Mar 15, 2007 11:50 pm
Posts: 299
Location: Virginia, USA
CZ time should be similar to garnet. You may need more diamond charge on the zinc lap, also be sure to clean swarf off the lap with lighter fluid (assuming you are using oil with your 8,000 mesh diamond); works wonders.
DD


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 Post subject: Re: Pre polishing CZ discussion.
PostPosted: Tue Jan 07, 2020 9:02 am 
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Have you considered inserting a 3000 grit lap ahead of the 8000 grit pre-polish? I know it is an extra step, but the total strokes (75) would likely be reduced.


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