Don B.
having dreams about rocks
Member since August 2012
Posts: 52
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Post by Don B. on Oct 14, 2012 18:56:17 GMT -5
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The Dad_Ohs
fully equipped rock polisher
Take me to your Labradorite!!
Member since September 2012
Posts: 1,860
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Post by The Dad_Ohs on Oct 14, 2012 21:07:17 GMT -5
frosted edges are usually from the rocks banging into each other as opposed to the tumbling action normally wanted... could be not enough cushioning media or maybe the rock is softer than other rock in the tumbler and it got bruised by a harder rock. A trip back to the previous stage or even back to medium grit will remove the frosting and then continue to finish with similar rock of hardness and you should be all set.
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Sabre52
Cave Dweller
Me and my gal, Rosie
Member since August 2005
Posts: 20,466
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Post by Sabre52 on Oct 15, 2012 9:12:43 GMT -5
Yep, the frosting we occasionally see is composed of microfractures and little impact dings under my microscope. I find that running a lot of smalls in a load along with the plastic pellets helps reduce this a lot. Obsidian seems particularly bad and I only run obsidian alone as any agate or jasper with it will really cause frosting. Aventurine quartz is another stone very prone to this problem....Mel
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Post by johnjsgems on Oct 15, 2012 9:41:17 GMT -5
You hear this a lot with underloaded barrels. If you start step one at 2/3 full and don't add filler or more rocks in further steps your barrel could be severely underloaded by polish step. Start at 3/4 full and maintain 3/4 full. Really fragile materials are helped by cushioning with plastic or ceramics.
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