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Post by Hard Rock Cafe on Dec 17, 2010 13:45:49 GMT -5
UPDATEI figured out what the problem was: me. I took the cabs back to 600 and reworked them through 3000. No more scratches. I must have rushed through the 600 step the first time and the scratches were there all along, just obscured. Thanks to Don, Gary, and John for their help! On the bright side, at least my belts aren't contaminated! ____________________________________________________ I've noticed that as I polish agate cabs on diamond belts I can go to 3000 grit and have a great shine (in fact, no need to polish). However, with jaspers I can still see tiny scratches. I assume that is because the jaspers are softer than agates. Is that correct? Would going to a smaller mesh/grit size help? If so, how far should I go? It seems like 100,000 is overkill, but maybe 14,000 is enough? Here are some pics of what I'm seeing. Under the lens I was able to see the scratches on the agate, too, but they're much less apparent than on the jasper (maybe the agate is glossier?). So are these normal size scratches for this belt or is cross contamination still likely? Thanks! Chuck
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Post by jakesrocks on Dec 17, 2010 13:58:37 GMT -5
Back up one or two grit sizes, and sand again. Make sure the cab is dry when you check for scratches. And above all else, make sure you're not getting cross contamination of your wheels or disks. On my Genie, I work several cabs in the same grit, and then change water and clean the pan and hood before moving to the next grit. If you're working with a good grade of jasper, it should be taking a shine by 3000 grit. Just a quick hit on felt and cerium oxide should finish it.
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Post by Hard Rock Cafe on Dec 17, 2010 14:40:14 GMT -5
Thanks Don. These are definitely scratches left by the 3000 belt (I can tell by the scratch pattern).
I am getting a shine, it's just not as good as the shine on the agates. I also work several stones at a time; the agates are fine, some of the jaspers are scratched.
Chuck
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Post by gr on Dec 17, 2010 14:48:46 GMT -5
I agree with Don and , not all jaspers are created equal. Usually jaspers, as I know them, are around 6.5 mohs. What do yhey look like after 600? you should be able to tell at that point what futher processing is going to produce. I've gotten good shine from 600, to felt w/cerium. Like Don says, watch that cross contamination. 1200 to 300 , then cerium should be a super shine at that point. One last ? , you know your rocks but are you sure it's jasper? Gary
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Post by gr on Dec 17, 2010 14:51:24 GMT -5
should be 3000, not 300. That,ll teach me to proof read
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Post by Hard Rock Cafe on Dec 17, 2010 15:05:13 GMT -5
I'll see if I can post some pics. Maybe this jasper is just too soft for a high shine.
I use an overhead water supply with sprayers, not a bubbler. My pump is suspended in the supply/waste bucket, so the heavy stuff goes to the bottom of the bucket. I think if I were having a cross contamination problem I would have it on all rocks.
Chuck
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Post by jakesrocks on Dec 17, 2010 15:50:34 GMT -5
There shouldn't be visible scratches left by your 3000 belt. By that grit it takes pretty high magnification to see scratches. My guess is that somewhere along the line you've contaminated your 3000 belt, and the contaminant has stuck in the belt.
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Post by Hard Rock Cafe on Dec 20, 2010 13:21:29 GMT -5
bump pics
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