electrocutus
spending too much on rocks
Member since October 2020
Posts: 331
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Post by electrocutus on Aug 4, 2022 13:42:41 GMT -5
I have a beginner question. I have rose quartz that I re-polished and it's now worse that the first time I tumbled it.
I started tumbling almost 2 years ago. I started with a Dr.Cool "Pro" rotary and now I also have a Lortone 33B (actually I have 3 1.5lbs barrels because I do small batches). One of my early batches was rose quartz. At the time I thought they came out pretty shiny and I was happy. But, with a little more experience and good grit, I thought I could re-polish them to get better results. I decided to take them through the whole process to improve the shapes as well. Now that I completed the polish and burnish, I find that they are now worse than after my first tumble. The "center" parts of the rocks are decent, but the edges are all dull. What's the most likely cause? - I use AO for polish. - did I leave them in the polish stage in the tumbler too long? I left them for about 2 weeks. - they looked pretty good at the end of each previous step. - was there too much room in the tumbler and they bumped too hard, ausing the edges to get dull? I had between 2/3 and 3/4 full. - I have been using the same polish for other batches, and a bahia agate batch I just completed look really good.
I continue to learn every day :-)
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Post by Bob on Aug 4, 2022 16:23:21 GMT -5
Although my barrels are larger than yours, I've had this same thing happen. A few years ago, I repolished quite a bit in alum ox that had been previously polished in cerium ox. It didn't happen every time though, but I could not figure it out. So I gave up trying. But instead of taking polished rocks right into another polish like that, I now take them back to unpolished by first running them through 1,000 grit. I don't think that problem has happened since, including after redoing all my previously done rose quartz, amethyst, rutilated quartz, and crystal quartz. However, this doesn't help in understanding the problem you mentioned.
Before the end of the year I may be redoing them a 3rd time in tin ox.
It takes weeks to do all this. Good luck.
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quartzilla
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Member since April 2020
Posts: 1,211
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Post by quartzilla on Aug 4, 2022 16:24:59 GMT -5
Is it polish stuck in the fractures? All my rose quartz I do is full of tiny fractures and those fractures get polish stuck in them like no tomorrow. I use a sonic cleaner and sometimes do a burnish load but on some pieces the doesn’t come all the way out.
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electrocutus
spending too much on rocks
Member since October 2020
Posts: 331
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Post by electrocutus on Aug 5, 2022 9:49:13 GMT -5
Is it polish stuck in the fractures? All my rose quartz I do is full of tiny fractures and those fractures get polish stuck in them like no tomorrow. I use a sonic cleaner and sometimes do a burnish load but on some pieces the doesn’t come all the way out. Thanks, that might contribute to it, but the burnishing step (~8 hours with Borax) didn't do much. The more I think about it the more I am leaning towards the rocks knocking around too loosely in the barrel. I'm trying again with some cushioning. We'll see how it goes! Someone in some other thread mentioned "gel" tumbling by adding metamucil and vinegar in th barrel. I might give that a try some day :-)
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Post by Bob on Aug 5, 2022 11:23:15 GMT -5
Is it polish stuck in the fractures? All my rose quartz I do is full of tiny fractures and those fractures get polish stuck in them like no tomorrow. I use a sonic cleaner and sometimes do a burnish load but on some pieces the doesn’t come all the way out. Boy do I know what you mean. That gets me on many pieces of rose, amethyst, rutilated, rock crystal though not much with smokey. A couple of years ago, I bought quite a bit of rose including some larger pieces between golfball and orange size. For the very first time ever, I did Opticon trt BEFORE any tumbling, thinking that it might close off those fractures. This is kind of a pain to do when the rock is still in the rough stage and it also wastes some of the resin and hardener. The first piece is nearing completion, sitting I think in my box for 1,000 grit prepolish next. But the results look so far like it might be working. I see no grit that has gone down in there.
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Post by Starguy on Aug 5, 2022 17:48:42 GMT -5
electrocutusI would try plastic pellets for almost any crystalline rocks. I don’t use them for agates but for crystalline rocks they help. My best recommendation would be to make sure your finish tumbler is 2/3 full with a nice mix of sizes.
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jamesp
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Member since October 2012
Posts: 36,154
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Post by jamesp on Aug 6, 2022 8:51:28 GMT -5
You must not have been happy with the initial polish if you made a 2nd attempt. Perhaps uncompleted 220 or 500 or 1000 or pre-polish steps are the problem ? The question then becomes do you go back and re-run 500 and/or 1000 and pre-polish. Or just pre-polish and polish ? Or all the way back to 220-500-1000-pre-polish-polish ?
If you had a decent polish initially and you simply ran them in polish again and the polish got worse you have a mechanical problem of the rocks hitting each other too hard. How do you know if the rocks are hitting too hard - simple, they are making sharp rattling sounds. I add slurry thickener till the rocks make a low groaning sound with little to no rattle. Especially when running crystalline quartz or glass. Alternatives - add smalls, go with 3/4+ fill, use plastics, slurry thickener, or whatever you are familiar with. Avoiding any golf ball+ sized rocks is a good idea too.
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nursetumbler
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Member since February 2022
Posts: 928
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Post by nursetumbler on Aug 6, 2022 20:48:49 GMT -5
Is it polish stuck in the fractures? All my rose quartz I do is full of tiny fractures and those fractures get polish stuck in them like no tomorrow. I use a sonic cleaner and sometimes do a burnish load but on some pieces the doesn’t come all the way out. Thanks, that might contribute to it, but the burnishing step (~8 hours with Borax) didn't do much. The more I think about it the more I am leaning towards the rocks knocking around too loosely in the barrel. I'm trying again with some cushioning. We'll see how it goes! Someone in some other thread mentioned "gel" tumbling by adding metamucil and vinegar in th barrel. I might give that a try some day :-)
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nursetumbler
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Member since February 2022
Posts: 928
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Post by nursetumbler on Aug 6, 2022 20:58:09 GMT -5
Thanks, that might contribute to it, but the burnishing step (~8 hours with Borax) didn't do much. The more I think about it the more I am leaning towards the rocks knocking around too loosely in the barrel. I'm trying again with some cushioning. We'll see how it goes! Someone in some other thread mentioned "gel" tumbling by adding metamucil and vinegar in th barrel. I might give that a try some day :-) electrocutusThe Metamucil works but to much and the rocks get suspended. When I use it I make up a bunch in something when I start cleaning so when I am ready to put it in for the next batch to tumble it has gelled. If it's to thick I can add some water to thin it out some. Good luck Kelly
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stefan
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Member since January 2005
Posts: 14,095
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Post by stefan on Aug 7, 2022 13:27:00 GMT -5
I have found that rotary tumblers take 3 weeks with Aluminium Oxide. I use plastic pellets with mine and just let it go!
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electrocutus
spending too much on rocks
Member since October 2020
Posts: 331
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Post by electrocutus on Aug 11, 2022 10:59:44 GMT -5
You must not have been happy with the initial polish if you made a 2nd attempt. Perhaps uncompleted 220 or 500 or 1000 or pre-polish steps are the problem ? The question then becomes do you go back and re-run 500 and/or 1000 and pre-polish. Or just pre-polish and polish ? Or all the way back to 220-500-1000-pre-polish-polish ? If you had a decent polish initially and you simply ran them in polish again and the polish got worse you have a mechanical problem of the rocks hitting each other too hard. How do you know if the rocks are hitting too hard - simple, they are making sharp rattling sounds. I add slurry thickener till the rocks make a low groaning sound with little to no rattle. Especially when running crystalline quartz or glass. Alternatives - add smalls, go with 3/4+ fill, use plastics, slurry thickener, or whatever you are familiar with. Avoiding any golf ball+ sized rocks is a good idea too. Thanks. I had re-run them from the very start 60/90 because I wanted to get them more rounded in addition to hoping for a better shine. I think they knocked around too much in the polish stage. I'm re-trying again :-)
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jamesp
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Member since October 2012
Posts: 36,154
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Post by jamesp on Aug 11, 2022 12:20:45 GMT -5
Good luck. Yep, depending on the intensity of the banging the damage could range from as little as dulling the polish slightly to full blown bruises and frosting. Usually if banging is the problem the edges get the most bruises or frosting.
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