Pdwight
has rocks in the head
Member since June 2003
Posts: 619
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Post by Pdwight on Oct 31, 2003 1:34:44 GMT -5
I bought some Ocean Jasper plates or slices off ebay some time back..these were exciting as usual for ocean jasper. I wanted to tumble them for a special project I have in mind. The pieces easily fit inside of my Model B barrel, I used lots of plastic buffer for the different stages. Well I ran 60 grit for 7 days , 220 for 7 days , 500 for 7 days and then ran fresh plastic beads and borax overnight....then I ran cerium oxide for 7 days with fresh new plastic beads...my problem it is still dull and matt finish :-( Now the corners are all smooth and rounded like you would expect..but no shine..what did I do wrong ? I scrubed everything very well between stages and used fresh new plastic beads for each stage. I added some blue agate that had been finished through the 500 grit stage 2 days ago when I first peeked a look to see how it was doing...I knew then that it was not going to "shine" now after 2 days the blue agate is responding as predicted..it looks pretty good for 2 days of final polish. I am confused...does anyone have any sugestions or does anyone want to flat lap or polish these for me ?? I am willing to pay. Thanks Dwight P
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Post by docone31 on Oct 31, 2003 18:55:56 GMT -5
Usually, the flats on cabachons will polish well in a tumbler. What size are the slices? also, I never found a 7 day polish enough to get anything but a satin finish. If it were me, I would have put sand in the mixture instead of plastic. Slabs have a lot of flat to polish. I am in the middle of remodeling my house to sell. If you cannot get a polish I would be willing to flat lap it, once I can again find anything else besides my tumbler. I can hear it under some furniture. My faceter is buried. I have a 1200 lap that might do a great job. I would go back to the 440 stage, tumble seven days. Then I would go with 660, 900, and then cerium oxide for 14 days. Since the grit works by contact abrasion, I would definately use sand with the slurry. Slabs do not have enough contact points. They will stick together unstead of rolling.
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Pdwight
has rocks in the head
Member since June 2003
Posts: 619
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Post by Pdwight on Nov 1, 2003 17:30:35 GMT -5
Follow up question Doc, In reguards to using sand as a filler to increase cutting and polishing action....what type of sand ?? just regular playground sand Also , I have a little sand left over from filling my shooting bag. it is super find black heavy (aluvial..spelling) volcanic sand that weighs more than it has a right to.it was a little expensive.but would this do..or do any of you nice folks have any experience with this type of material ?? Thanks Dwight P PS sorry I have been in and out latley..started new job and my wife has been in the hospital with a really serious catastrophic illness.
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Post by docone31 on Nov 1, 2003 17:54:30 GMT -5
I would just use conventional sand. I am not sure what the black sand is and I would hate to see it be a coarse grit. My prayers are with you guys. I hope all fares well. Contact me if you need to talk.
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Pdwight
has rocks in the head
Member since June 2003
Posts: 619
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Post by Pdwight on Nov 1, 2003 18:00:07 GMT -5
showing my ignorance here...the particular size of the grains has nothing to do with grit is that correct ?? This stuff probbly is 1/8 to 1/15 the size of regular sand...it is super fine in size...I mean like nothing you have probbly ever seen....actually I just found out that "Reptile sand" may be the same thing..also "Casting sand" is similar...but this is finer is particle size. Dwight P
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Post by docone31 on Nov 1, 2003 18:58:22 GMT -5
It is not the size, rather the hardness. Essentially, the grit is a layer between two objects. As the objects move against each other, friction becomes the eroding factor. Two objects of the same hardness will not erode as fast as two dissimilar objects. The grit changes the hardness factor. Sand acts like a boundary layer. The edges of the grit chisel off small pieces untill the rough is gone. Adding sand, the sand erodes into a mud with small pieces. When I do this, I run an extra long run. There is some complication in the beginning with the sand, and a dulling of a polish. With time and a longer run, the shine is brought back. With slabs, the large, in proportion, sides do not rub together. there would be no grinding action, merely sliding and the grits would not have the chance to replenish. Slabs are tough to polish. My best results have been putting a few slabs in a tumble with other stones. Using a sanding wheel and a buff is a faster way to polish, or a flat lap. Tumbling slabs are more time consuming, and the results are variable. I have seen some beautiful tumble polished agate slices. It can be done.
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