blackgirlrocks
starting to shine!
Member since November 2023
Posts: 49
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Post by blackgirlrocks on Nov 3, 2023 15:57:54 GMT -5
I have a batch of Unakite coming out of 500. I saw a thread that said opaque rocks don't benefit from 1000 grit. Should I go straight to AO polish?
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stefan
Cave Dweller 
Member since January 2005
Posts: 14,113
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Post by stefan on Nov 3, 2023 17:42:26 GMT -5
I wouldn't skip it.
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blackgirlrocks
starting to shine!
Member since November 2023
Posts: 49
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Post by blackgirlrocks on Nov 3, 2023 19:11:49 GMT -5
Thank you
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Post by rockjunquie on Nov 3, 2023 20:46:14 GMT -5
You may not be aware, but you stumbled into the world's best resource on tumbling right here. I wouldn't trust the rule about opaque rocks. You'll need to learn about the Moh's hardness of your rocks. That will tell you a lot about how to and with what to tumble with. We have some realllllly superb tumblers here.
Glad you found us.  |
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dshanpnw
fully equipped rock polisher
Member since December 2020
Posts: 1,158
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Post by dshanpnw on Nov 3, 2023 21:47:57 GMT -5
I would go with the 1000 grit, I always do. Let us know how they turn out.
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blackgirlrocks
starting to shine!
Member since November 2023
Posts: 49
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Post by blackgirlrocks on Nov 4, 2023 19:59:28 GMT -5
Had a newbie moment and started the polish. Is it too late to go back? |
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iamchris
has rocks in the head
Member since June 2023
Posts: 722
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Post by iamchris on Nov 5, 2023 7:03:31 GMT -5
I'm also a newbie so take what I say with a grain of salt.
You've already spent the grit, I'd see how it comes out after it's done. If you're happy with it, keep it. If not, go back to 1000 and then repeat final polish.
If you decide you're happy with it and you ever do another batch of unakite, it would be cool to compare both batches - the one that skipped 1000, and the one that went through all grit levels.
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blackgirlrocks
starting to shine!
Member since November 2023
Posts: 49
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Post by blackgirlrocks on Nov 5, 2023 7:18:56 GMT -5
I'm also a newbie so take what I say with a grain of salt. You've already spent the grit, I'd see how it comes out after it's done. If you're happy with it, keep it. If not, go back to 1000 and then repeat final polish. If you decide you're happy with it and you ever do another batch of unakite, it would be cool to compare both batches - the one that skipped 1000, and the one that went through all grit levels. That's what I'm thinking. I'll wait 4 days and check it. I was concerned about fracturing because of the hardness so I didn't want to go through 1000 unnecessarily. My nerves got the best of me.🤞 |
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blackgirlrocks
starting to shine!
Member since November 2023
Posts: 49
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Post by blackgirlrocks on Nov 8, 2023 7:35:59 GMT -5
 These are dry. However, because of scratches from a broken unakite and undercutting during previous stages I think I'll do these over. What stage can I start at to minimize more undercutting? |
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RockyBeach
spending too much on rocks
Member since July 2023
Posts: 342
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Post by RockyBeach on Nov 8, 2023 11:29:47 GMT -5
These are dry. However, because of scratches from a broken unakite and undercutting during previous stages I think I'll do these over. What stage can I start at to minimize more undercutting? Am looking forward to replies about dealing with undercutting which is one of my major problems. It seems to happen to "perfect" stones when they reach polish stage. You did get what looks to me like a nice shine ! |
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Post by chris1956 on Nov 8, 2023 14:27:45 GMT -5
These are dry. However, because of scratches from a broken unakite and undercutting during previous stages I think I'll do these over. What stage can I start at to minimize more undercutting? Am looking forward to replies about dealing with undercutting which is one of my major problems. It seems to happen to "perfect" stones when they reach polish stage. You did get what looks to me like a nice shine ! I have done some unakite and the ones that I have issues with undercutting tend to be the ones with black parts in them which looks like most of the ones in your pic. Not sure there is a way around that. Did the ones that don't have black parts turn out better? |
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blackgirlrocks
starting to shine!
Member since November 2023
Posts: 49
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Post by blackgirlrocks on Nov 8, 2023 14:46:20 GMT -5
Am looking forward to replies about dealing with undercutting which is one of my major problems. It seems to happen to "perfect" stones when they reach polish stage. You did get what looks to me like a nice shine ! I have done some unakite and the ones that I have issues with undercutting tend to be the ones with black parts in them which looks like most of the ones in your pic. Not sure there is a way around that. Did the ones that don't have black parts turn out better? I take very poor pictures. All of these are Forest green, mint green, reddish pink, and pale pink. All of the pale pink has undercut. On every piece. |
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blackgirlrocks
starting to shine!
Member since November 2023
Posts: 49
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Post by blackgirlrocks on Nov 8, 2023 14:48:20 GMT -5
So of the darker spots are quartz.  |
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blackgirlrocks
starting to shine!
Member since November 2023
Posts: 49
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Post by blackgirlrocks on Nov 8, 2023 14:52:53 GMT -5
Overall I can tell from the zebra jasper I had mixed in that running the 1000 grit would have helped.
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Post by chris1956 on Nov 8, 2023 21:48:55 GMT -5
So of the darker spots are quartz. The pink stuff (orthoclase feldspare) is the softest of the 3 materials so if anything was going to undercut that would probably be the one. I took a look at some of the ones I have polished and there is a slight amount of undercutting on the feldspare (most of the stones) but they still seemed to polish pretty well although it isn't perfect as the undercutting makes kind of a wavy surface (not perfectly flat). Some of the ones with feldspare (assuming it is feldspare) don't seem to exhibit the undercutting. I typically use a rotary tumbler for 80 grit and then use a Lot-O vibratory tumbler for 220, 500, and micro alumina. Are you using a rotary tumbler for all stages? I haven't done that with unakite. |
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dillonf
fully equipped rock polisher
Hounding and tumbling
Member since February 2022
Posts: 1,622
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Post by dillonf on Nov 8, 2023 22:17:27 GMT -5
These are dry. However, because of scratches from a broken unakite and undercutting during previous stages I think I'll do these over. What stage can I start at to minimize more undercutting? Hi. Your unakite looks nice. Undercutting can happen in any type of tumbler, but for me it is more common in the vibratory tumbler during the polish stage. I have had similar experiences as RockyBeach where I have had perfectly smooth rocks get pitted in the vibratory. I have had some luck minimizing pitting by doing all stages in the rotary tumbler and avoiding the vibratory when doing material that is prone to pitting. That said getting a high quality polish using a rotary can be a bit trickier. Here is what I would try: All in a rotary tumbler (3lb) 80 SC grit for 1 week (tumbler 75% full - ceramics if necessary) 220 SC grit for 1 week (tumbler 75% full - ceramics if necessary) 500 AO grit for 1 week (tumbler 75% full - ceramics if necessary) 1000 AO grit for 1 week (tumbler 75% full - ceramics if necessary) AO polish (rock shed) for 2 weeks (tumbler 80% full - plastic pellets for filler) Let it roll for 2 weeks straight with no clean out or checks. No guarantees, but if I was in your position that is what I would do. You may need to let the 80 grit stage run a little longer if you don't get full grit break down. Amount of grit: if you are using a 3lb tumbler I'd use 3 tablespoons of grit, I'd also add 1/2-3/4 tablespoon of borax at each stage. |
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blackgirlrocks
starting to shine!
Member since November 2023
Posts: 49
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Post by blackgirlrocks on Nov 8, 2023 22:52:36 GMT -5
chris1956 yes I only have rotary for now. dillonf I can do this but I only have 60/90 and 120/220. Everything else I have. Half of my unakite came from Rock Shed and the other 2lbs came from Amazon. I've been looking at using Physillum as a thickener. Not much info for rotary use on the forum. I currently use borax in every stage.
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dillonf
fully equipped rock polisher
Hounding and tumbling
Member since February 2022
Posts: 1,622
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Post by dillonf on Nov 9, 2023 7:34:46 GMT -5
chris1956 yes I only have rotary for now. dillonf I can do this but I only have 60/90 and 120/220. Everything else I have. Half of my unakite came from Rock Shed and the other 2lbs came from Amazon. I've been looking at using Physillum as a thickener. Not much info for rotary use on the forum. I currently use borax in every stage. If I was using 60/90 I'd let it tumble for 2 weeks - I have never gotten full grit breakdown in one week with that grit. 120/220 is perfect. If you have already polished them in the rotary what I suggested may not work, but is worth a try. In general when I polish in the rotary I have the barrel more full so there is a more gentle tumble with the thinner slurry and I let it run longer because it takes longer for the grit to breakdown in a gentle tumble. From what I have seen, and based on my own experience tumbling unakite I think pitting is related to the quality of the stone. Some stuff you will have no issues with and others can be problematic. I got some from the rock shed about 1-2 years ago and I had no issues with pitting and I didn't do anything special, but I have read quite a few posts where people have had pitting issues with it. I say that to say don't beat yourself up - it may not have anything to do with your process - it may just be the nature of the material you have. Best of luck! |
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Post by chris1956 on Nov 9, 2023 21:05:08 GMT -5
chris1956 yes I only have rotary for now. dillonf I can do this but I only have 60/90 and 120/220. Everything else I have. Half of my unakite came from Rock Shed and the other 2lbs came from Amazon. I've been looking at using Physillum as a thickener. Not much info for rotary use on the forum. I currently use borax in every stage. If I was using 60/90 I'd let it tumble for 2 weeks - I have never gotten full grit breakdown in one week with that grit. 120/220 is perfect. If you have already polished them in the rotary what I suggested may not work, but is worth a try. In general when I polish in the rotary I have the barrel more full so there is a more gentle tumble with the thinner slurry and I let it run longer because it takes longer for the grit to breakdown in a gentle tumble. From what I have seen, and based on my own experience tumbling unakite I think pitting is related to the quality of the stone. Some stuff you will have no issues with and others can be problematic. I got some from the rock shed about 1-2 years ago and I had no issues with pitting and I didn't do anything special, but I have read quite a few posts where people have had pitting issues with it. I say that to say don't beat yourself up - it may not have anything to do with your process - it may just be the nature of the material you have. Best of luck! I think I agree about the pitting. I grabbed 10 polished unakite rocks from a bag. 7 of them had some pitting or cracking to one extent or another. But they still all look great polished. Maybe you won't get the perfect polish that you would get on something like agates or other rocks, but they still really shine, at least in my opinion. |
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