ataraktos
starting to spend too much on rocks
Member since January 2020
Posts: 140
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Post by ataraktos on Jul 28, 2020 13:49:12 GMT -5
Is there any definitive size info on polishes? Mostly I have stuck with the ao polish from TRS since I see folks getting amazing results with that. But I have some TXP and a small amount of cerium, chrome oxide to try.
Anyway, I'm wondering, since polish is just super-fine grit, do I need to worry about contamination with different polishes, in a dedicated (dry) polish bowl? I believe I've read that TXP isn't as fine as aluminum oxide polishes. I don't have much idea at all about cerium or co. How meticulous do I need to be, cleaning the bowl, when I plan to use a different polish?
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Post by aDave on Jul 28, 2020 22:29:18 GMT -5
Based upon a discussion I had with Shawn at TRS, I learned his AO polish is 13,000 (1.5 microns). TXP is also AO, but It is larger - 8,000 (3 microns). I can't tell you about cerium, as I've never used it nor cared to - hence, I've done no research about it.
While I've never dry polished, as far as contamination goes, I'm not sure it's really that much of an issue if you're giving the your bowls a good cleaning. I'd have to believe that even something like TXP should be broken down so much after a stage, it's probably at least as small as new stuff from TRS.
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ataraktos
starting to spend too much on rocks
Member since January 2020
Posts: 140
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Post by ataraktos on Jul 29, 2020 11:51:56 GMT -5
Thanks aDave! I'm completely new to dry polishing stuff but I'm not sure it breaks down as fast as in a wet run ... the claim is it can be re-used multiple times. Or maybe wet polish could be reused too but it's just kind of messy to keep? I reckon I'll be scrubbing the dry bowl meticulously clean, before switching to a different polish.
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Post by greig on Jul 29, 2020 13:14:37 GMT -5
I really like the idea of cleaning the tumbler barrel well between batches. I don't reuse polish because (1) I am lazy and (2) I would want to clean the used polish so there is no contamination transferred between batches. That said, I think you are fine using the same barrel for fine and super fine A/O. FYI - I just recently ordered some 0.5 micron AO. Crazy expensive, but it might be fun to see what it will do...and I won't be buying a new barrel for it.
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ataraktos
starting to spend too much on rocks
Member since January 2020
Posts: 140
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Post by ataraktos on Jul 29, 2020 18:27:38 GMT -5
oh wow, I want to see what that super-fine ao does, too greig ! saving the dry corn cob/polish in a big ziploc to reuse wasn't too much effort for me. but cleaning the bowl - yeah, i'm lazy too and i enviously noted another brand of cheap brass tumbler sells extra bowls for $7. but not my brand.
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jamesp
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Post by jamesp on Jul 31, 2020 5:33:32 GMT -5
Many vibe users use AO 500 to get a polish. Meaning AO 500 must be breaking down to AO 14,000/1 micron to get a nice reflective polish. Many do an AO 14,000 run after the AO 500 and can barely tell a difference in the polish. I use AO 220 to get a nice pre-polish(showing vivid image reflections but not a wet polish) in the vibe. Meaning the AO 220 broke down to the AO 3000 to 5000 range. Then I use AO 14,000 to close the deal quicker than letting the AO 220 break down to 14,000 or smaller. Point being, AO 220 will eventually break down to obtain a fine 1 micron polish. I left these rocks in AO 22 in the vibe for like 12 days. www.flickr.com/photos/67205364@N06/sets/72157681139306525 AO 22 is some big particles. The AO 22 particles did not actually break down to nothing, the particles were still in the vibe but they had assumed a polish themselves. That's right, little tiny polished balls and ovals. By the way most tumbling ceramics we use are like 97% aluminum oxide. Fine chinaware is almost pure aluminum oxide ceramic too. I never tried other finishing abrasives or polishes, just aluminum oxide. But have tried many forms of aluminum oxide like brown/white/black.... cheap sand blasting grades of AO and expensive AO's. They all work the same in a tumbler in my experience. You mentioned particle size contamination. You might be surprised what the allowable particle size variation is in say for example AO 14,000. It is allowable to market abrasives with large variations for an advertised particle size. Inexpensive AO 14,000 probably ranges from AO 2000 to AO 40,000. Check the 'allowable' bell curve data for particle size for the abrasive you purchase. If the supplier will give you this information. If you like to spend money, insist on AO 14,000 with +/-5% particle size variation. Best get your wallet out. Such precision sifted/graded abrasives are used on high precision applications like helicopter propeller shafts where lives are at stake. Tumbling beats abrasives down so much it is a waste to buy +/-5%. This is a benefit of tumbling.
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jamesp
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Post by jamesp on Jul 31, 2020 5:39:09 GMT -5
Typical bell curve for allowable particle size. Note Comco is bragging their spread is less. This looks like a graph for AO 60 micron. Note particle size is all over the chart. Particles vary from 10 to over 100 microns, so times 10 variation in lower and upper 10 percent. The advertised size is a joke. 220 grit is the same as 63 microns. 30 grit is the same as 559 microns 60 grit is the same as 254 microns. etc So AO 220 is actually closer to AO 120/220/500. AO 220 +/- 5% should cost about $50/ounce.
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Post by greig on Jul 31, 2020 17:23:51 GMT -5
I found the same chart. Interesting discussion. I was under the original impression that one could reuse polish because AO didn't break down in a tumble at the same rate as SC ... and basically what you start with is what you finish with. Now, it seems there is an argument to reuse polish (after cleaning it) because you have a finer AO after every polish. hmmm
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Post by HankRocks on Jul 31, 2020 18:51:50 GMT -5
I found the same chart. Interesting discussion. I was under the original impression that one could reuse polish because AO didn't break down in a tumble at the same rate and basically what you start with is what you finish with. Now, it seems there is an argument to reuse polish (after cleaning it) because you have a finer AO after every polish. hmmm I have been re-using polish for a couple years now. It polishes well. It does become a bit "slurried"(is that a word) or may be better to say diluted with the material removed from the rocks during the polishing process. This removed material should be extremely fine and in my experience does not seem to diminish the effectiveness of the re-used polish. I do end up putting more of the saved polish in as it also acts as a nice slurry. If I am re-using I am not worried about cost. Even if I tumble for another 20 years I do not see buying any more polish. It does take a little extra effort saving polish. I have a couple reserved buckets that I let the polish settle to the bottom of the bucket, remove the clear water and then dry cake the polish.
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Post by rmf on Jul 31, 2020 21:59:17 GMT -5
check out juxtamorph.com/lapidary-polishing-compounds/Polish Information: Cerium Oxide Our high quality, 85% purity, optically graded cerium, is excellent for polishing glass. One of the best all-purpose polishes. Also used to polish quartz, agate, opal, obsidian, etc Cerium Oxide 3.5 MICRON SIZE Cerium-R Oxide 1.2 MICRON SIZE Linde 'A' Polish A .3 micron alumina powder that is 99.98% pure aluminum oxide polishing powder with a 9 mohs hardness. A super polish for almost any gemstone. Mirco Aluminum: Covington's Gold Label Polish #1 99% pure micro alumina polishing powder. Excellent for vibrating tumblers, lappers, and ultrasonic machines. Great for Petrified woods, Agate, Rhodocrosite, Jade and other stones. Approximate size 2 - 3 microns and a 9 on the MOHS scale. Covington's Gold Label Polish #2 99% pure micro alumina polishing powder. Excellent for vibrating tumblers, lappers, and ultrasonic machines. Works especially well with Leather or Felt. Great for super fine polish on all hard and soft stones. Approximate size .5 microns and a 9 on the MOHS scale. Red Rouge Powder Inexpensive polish powder used for tumbling. Often used with walnut shell to polish brass. A good final polish for glass and obsidian. Also used with felt belt to polish glass and metals. Red Rouge * 3.5 to 5 MICRON SIZE Tin Oxide 99.9% Ultra High purity tin oxide. Over 85% particle size distribution 1 micron or less, and 58% is .37 micron. Excellent polishing on almost any gemstone including hard to polish stones.
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jamesp
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Post by jamesp on Aug 1, 2020 5:06:22 GMT -5
HankRocks I think we unknowingly wash AO down the drain every time we clean out an AO run. I found AO 22 particles albiet rounded in the vibe after 10 days. Only because they were big and bright white and dense at bottom of vibe hopper. AO 80-220-500-1000, regardless of size I believe we are washing rounded particles of AO down the drain regardless of size when doing a clean out. Who is looking for such small particles mixed/masked with slurry anyway ? Maybe AO 80 is visible, not 220 and smaller. Yours and others re-use of AO polish pretty much closes the deal - AO don't go away easily like brittle SiC because they are a tough ceramic. I think AO polish and other AO grit sizes wear down more and more but it takes a long time greig. Just like most tumbling ceramics since most of them are 97-98% pure aluminum oxide, they take a long time to wear down too. That is why most tumbling ceramics are 97% fused aluminum oxide(ceramic). It is easy to collect used AO polish, polish makes little slurry. Used AO 500 for example makes a good bit of slurry, not as easy to separate the AO from slurry. AO is a fine rock polishing abrasive at any size since it rounds from any size and then imparts a polish.
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jamesp
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Post by jamesp on Aug 1, 2020 5:16:54 GMT -5
Probably the best polish I ever had was from AO 22. I was shocked when I left this one pound agate in the vibe for 10 days using AO 22 and ended up with this fine polish. This is virgin AO 22 on 1/4" ruled paper. Big particles.
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Post by HankRocks on Aug 1, 2020 7:49:54 GMT -5
HankRocks I think we unknowingly wash AO down the drain every time we clean out an AO run. I found AO 22 particles albiet rounded in the vibe after 10 days. Only because they were big and bright white and dense at bottom of vibe hopper. AO 80-220-500-1000, regardless of size I believe we are washing rounded particles of AO down the drain regardless of size when doing a clean out. Who is looking for such small particles mixed/masked with slurry anyway ? Maybe AO 80 is visible, not 220 and smaller. Yours and others re-use of AO polish pretty much closes the deal - AO don't go away easily like brittle SiC because they are a tough ceramic. I think AO polish and other AO grit sizes wear down more and more but it takes a long time greig . Just like most tumbling ceramics since most of them are 97-98% pure aluminum oxide, they take a long time to wear down too. That is why most tumbling ceramics are 97% fused aluminum oxide(ceramic). It is easy to collect used AO polish, polish makes little slurry. Used AO 500 for example makes a good bit of slurry, not as easy to separate the AO from slurry. AO is a fine rock polishing abrasive at any size since it rounds from any size and then imparts a polish. In my case, I only use 80 AO or 500 AO in the Pre-Polish stage; 80 for the larger rounded material such as Agate or Jasper and 500 for the Pre-form loads and for Ark Quartz. I do keep the washed off slurry separate for later use in the same AO size run. That extra sorting may be un-necessary but it seems to work for me. I have found that for Ark Quartz, 80 AO breaks down much slower and leaves marks that the Polish run can't remove if not run long enough. The molecular orientation in the Quartz Crystal must be the reason for this, the 80 AO survives the collisions between two Crystals, much better than between two agates/jaspers. The used AO run slurry makes a nice add to subsequent runs, instant slurry. Note I am running almost all of the pre-polish runs in a Rotary.
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jamesp
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Post by jamesp on Aug 1, 2020 9:02:58 GMT -5
You might find some of the AO 80 particles in the used slurry HankRocks. Maybe a magnifier would help. If the slurry is put in a jar with water and shaken well the AO 80 particles may lay on the bottom first since AO is quite a bit denser than quartz's and agates.
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EricD
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Post by EricD on Aug 1, 2020 9:42:55 GMT -5
Probably the best polish I ever had was from AO 22. I was shocked when I left this one pound agate in the vibe for 10 days using AO 22 and ended up with this fine polish. This is virgin AO 22 on 1/4" ruled paper. Big particles. "Brown aluminum oxide is not friable, it does not break apart easily and keeps its shape and cutting edge. As it wears it slowly rounds itself out. White, on the other hand, is friable, as it wears it slowly shears apart, which has the effect of creating new cutting edges."
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jamesp
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Post by jamesp on Aug 1, 2020 13:04:10 GMT -5
The AO 22 above looks white in the container EricD. Under magnification is is dead clear go figure.
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EricD
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Post by EricD on Aug 1, 2020 16:28:23 GMT -5
The AO 22 above looks white in the container EricD . Under magnification is is dead clear go figure. I was mainly suggesting that as white AO it should not round, instead it should break into smaller cutting pieces with sharp edges over time.
Perhaps you got something entirely different? Maybe the forces in your vibe were not brutal enough to fracture AO 22? I suppose that is yet another thing to be considered when choosing a grit size.
The effect of it sure was brilliant!
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jamesp
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Post by jamesp on Aug 1, 2020 16:43:26 GMT -5
The AO 22 above looks white in the container EricD . Under magnification is is dead clear go figure. I was mainly suggesting that as white AO it should not round, instead it should break into smaller cutting pieces with sharp edges over time.
Perhaps you got something entirely different? Maybe the forces in your vibe were not brutal enough to fracture AO 22? I suppose that is yet another thing to be considered when choosing a grit size.
The effect of it sure was brilliant!
Like silica aluminum oxide exists in so many forms and is complicated. I have spent time researching it and most of the literature is high tech and quickly goes over my head. It gets real expensive when made into microscopic balls. Surface finishes that are involved in life support machinery often require precision aluminum oxide abrasives. Our kaolin clay is one of the larger sources for it. Chinese mastered ceramic containers long ago, the clay they used is china clay. Fine china is apparently made out of it. Our ceramic media may be the same ceramic as fine china is made of. It is common in aluminum ores. If 'aluminum oxide abrasives magnified' is searched many forms can be seen in images.
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EricD
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Post by EricD on Aug 1, 2020 16:49:13 GMT -5
I was mainly suggesting that as white AO it should not round, instead it should break into smaller cutting pieces with sharp edges over time.
Perhaps you got something entirely different? Maybe the forces in your vibe were not brutal enough to fracture AO 22? I suppose that is yet another thing to be considered when choosing a grit size.
The effect of it sure was brilliant!
Like silica aluminum oxide exists in so many forms and is complicated. I have spent time researching it and most of the literature is high tech and quickly goes over my head. It gets real expensive when made into microscopic balls. Surface finishes that are involved in life support machinery often require precision aluminum oxide abrasives. Our kaolin clay is one of the larger sources for it. Chinese mastered ceramic containers long ago, the clay they used is china clay. Fine china is apparently made out of it. Our ceramic media may be the same ceramic as fine china is made of. It is common in aluminum ores. If 'aluminum oxide abrasives magnified' is searched many forms can be seen in images. With such wide variety I guess it's important to have a supplier that knows much more than I do about the different types and grades, and their performance in the end use(s) they are advertised for.
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jamesp
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Post by jamesp on Aug 1, 2020 19:39:52 GMT -5
Like silica aluminum oxide exists in so many forms and is complicated. I have spent time researching it and most of the literature is high tech and quickly goes over my head. It gets real expensive when made into microscopic balls. Surface finishes that are involved in life support machinery often require precision aluminum oxide abrasives. Our kaolin clay is one of the larger sources for it. Chinese mastered ceramic containers long ago, the clay they used is china clay. Fine china is apparently made out of it. Our ceramic media may be the same ceramic as fine china is made of. It is common in aluminum ores. If 'aluminum oxide abrasives magnified' is searched many forms can be seen in images. With such wide variety I guess it's important to have a supplier that knows much more than I do about the different types and grades, and their performance in the end use(s) they are advertised for. A neighbor worked as a district salesman for Washington Mills. He rarely had samples of silicon carbide but he was always loaded up with a plethora of 5 to 10 pound cans of aluminum oxide samples from AO 22 to AO 50,000. Colors were browns, white, grays and black.. Some were for military applications, some for industry, some for product mixes. Some of it was $2/pound and some $50/ounce. I ran it thru the tumblers over the years only respecting the grit size and never noticed much difference in them other than they acted like the grit size they were listed as. I know buy AO 500 and 14,000 from the Shed and the others(mostly AO 220) from the Abrasive Armory on EBAY. The Abrasive Armory's AO is always white.
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