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Post by pauls on Jan 25, 2016 18:35:30 GMT -5
I have been searching for 500 Aluminium Oxide in Australia for quite a while but haven't been able to find any, I'm still looking but in the meantime........ In the Spirit of jamesp and his experimenting, I am trying a little experiment with a load that just came out of 600 grit SiC. I can't get 500 AlO here in Oz. but I know from my foundry hobby that fireclay is AlO so put a bit in with my rocks and ran it overnight, this morning the rocks are running in a nice slurry and unbelievably are starting to get a polish, this is just white Kaolin clay that I scooped up from beside the driveway outside the fence of a local clay pit. I didn't expect anything at all to happen and I doubt it would work with soft rocks because of probable Quartz grit contamination, but I am really surprised at what is happening with my Agate and pet wood. Zero cost polishing, what could be better. I will keep you posted about success or failure.
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Post by orrum on Jan 25, 2016 18:44:45 GMT -5
Hey 600 grit will break to 1200 very fast in a vibe and then it will start to polish!
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jamesp
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Post by jamesp on Jan 25, 2016 19:16:10 GMT -5
I have been searching for 500 Aluminium Oxide in Australia for quite a while but haven't been able to find any, I'm still looking but in the meantime........ In the Spirit of jamesp and his experimenting, I am trying a little experiment with a load that just came out of 600 grit SiC. I can't get 500 AlO here in Oz. but I know from my foundry hobby that fireclay is AlO so put a bit in with my rocks and ran it overnight, this morning the rocks are running in a nice slurry and unbelievably are starting to get a polish, this is just white Kaolin clay that I scooped up from beside the driveway outside the fence of a local clay pit. I didn't expect anything at all to happen and I doubt it would work with soft rocks because of probable Quartz grit contamination, but I am really surprised at what is happening with my Agate and pet wood. Zero cost polishing, what could be better. I will keep you posted about success or failure. Kaolin is from felspar weathering pauls. Apparently rich in aulumina. Look up the chemical formulas and description of make-up and you will see the high percentage of aluminum oxide, like 1/3. Truck loads/acres of kaolin in many locations. Not rare. You may be able to run your coarse SiC for two weeks to break it down good and then go straight to kaolin. Aluminum Oxide is a cool finishing abrasive. It just turns into smooth balls, not sure the size matters. Smooth balls that impart a polish. The quartz sand may cause issues with softer rock, probably not agate and wood. I think it tumbles smooth too. Look kaolin on Wikipedia and see it's many uses and make up. Please post results.
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Post by pauls on Jan 25, 2016 20:40:50 GMT -5
I just had a look at the analysis of the clay from the pit. Its 30% AlO around 50% Silica, so it probably would not work with softer materials. Heck if it doesn't work I don't care, I can just go back to standard procedure. The clay is very fine and feels slippery even when dry, a lot like Talc, it makes a really smooth slippery slurry (try saying that rapidly). We'll see how they look after tonight, I can't run the tumbler during the day at the moment, its far too hot.
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jamesp
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Post by jamesp on Jan 25, 2016 22:49:03 GMT -5
Yea that stuff is slicker than a greased pig. Middle Georgia has some of the biggest kaolin pits in the world with serious processing operations.
Maybe they have separated and graded the AIO. It is not worth much in the raw state, has to be processed in some form to be marketable.
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jamesp
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Post by jamesp on Jan 26, 2016 7:20:42 GMT -5
History of kaolin, Huber Georgia. J.M. Huber, one of the largest privately held companies in the US. www.huber.com/about-us/our-history-t1/K-White 7000, a refined kaolin: Ultrafine and superwhite calcined kaolin for the ceramics industry is characterized by high dielectric strength, high fusion point, low water content, and high green strength. It is commonly used in whiteware products, insulators, refractories, and bio-ceramics. K-WHITE 7000 Al2O3 45±2.0% SiO2 52±2.0%" Such refined kaolin is probably the make up of ceramic media used for tumbling. Ceramic media probably serves as giant grit particles that impart a finish. Add AO 500 to rocks and ceramic media, it imparts a 500 finish to the rocks and lesser so to the harder ceramic media. As the AO 500 breaks down the rocks and the ceramic media impart a polish to the softer rocks. Obviously the ceramic media is harder than Mohs 7 rocks, that is why it can be used over and over. Guessing, but I think that is what is going on.
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Post by pauls on Jan 26, 2016 15:58:05 GMT -5
After about 36 hours in the Kaolin slurry the rocks have taken a reasonable prepolish all over. Kaolin clay a reasonable prepolish but I don't think its going to progress to a proper wet look polish, I think I will throw in a bit of Cerium with the slurry and see what happens, its an experiment after all.
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jamesp
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Post by jamesp on Jan 26, 2016 20:03:04 GMT -5
Processed kaolins may do the polish. Raw kaolin probably has too many size variations and impurities. I have come close to a polish with clays. Graded abrasive probably hard to beat at the polish level. Interesting stuff non the less.
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Post by mohs on Jan 26, 2016 20:17:46 GMT -5
what was the substance that started the ceramic wars around the 17th century ? something China was using that the rest of world (especially England or Italy) wanted to know the secret of.
don't mean to hijack the thread but since you guys are doing the research figured you'd find it interesting...
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jamesp
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Post by jamesp on Jan 26, 2016 20:37:16 GMT -5
what was the substance that started the ceramic wars around the 17th century ? something China was using that the rest of world (especially England or Italy) wanted to know the secret of. don't mean to hijack the thread but since you guys are doing the research figured you'd find it interesting... It was china clay and their process using really high temps. China had been doing the ceramic thing way long ago. I think Europe was all about porcelain until trade started w/the far east. I have a mechanical engineering degree from Georgia Tech. I remember walking by the School of Ceramic Engineering. The school is still there. Apparently research and development of ceramics is a big ticket item in modern day life. Glad that pauls tried the kaolin. Hope it works for his pre polish.
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Post by Deleted on Jan 26, 2016 23:02:57 GMT -5
what was the substance that started the ceramic wars around the 17th century ? something China was using that the rest of world (especially England or Italy) wanted to know the secret of. don't mean to hijack the thread but since you guys are doing the research figured you'd find it interesting... It was china clay and their process using really high temps. China had been doing the ceramic thing way long ago. I think Europe was all about porcelain until trade started w/the far east. I have a mechanical engineering degree from Georgia Tech. I remember walking by the School of Ceramic Engineering. The school is still there. Apparently research and development of ceramics is a big ticket item in modern day life. Glad that pauls tried the kaolin. Hope it works for his pre polish. I think the new world was all "ceramics" while the east had the secret process for the highly desirable "porcelains". Maybe I suck.
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jamesp
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Post by jamesp on Jan 27, 2016 4:37:55 GMT -5
It was china clay and their process using really high temps. China had been doing the ceramic thing way long ago. I think Europe was all about porcelain until trade started w/the far east. I have a mechanical engineering degree from Georgia Tech. I remember walking by the School of Ceramic Engineering. The school is still there. Apparently research and development of ceramics is a big ticket item in modern day life. Glad that pauls tried the kaolin. Hope it works for his pre polish. I think the new world was all "ceramics" while the east had the secret process for the highly desirable "porcelains". Maybe I suck. The Chinese material is referred to as porcelain. Terminology is complicated, as was their process, engineer would call it ceramic composition. Porcelain materials were mixed in like pottery stone making it a hybrid. Kaolin was a major component. "" Materials[edit] Chinese porcelain is mainly made by a combination of the following materials: Kaolin - essential ingredient composed largely of the clay mineral kaolinite. Pottery stone - are decomposed micaceous or feldspar rocks, historically also known as petunse. Feldspar Quartz[5] "" China such a big country they had many high tech porcelains/ceramics. Formulas beyond much modern technology. Wiki: en.wikipedia.org/wiki/Chinese_ceramics
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Post by pauls on Jan 27, 2016 5:18:43 GMT -5
Cooler here today, so ran the tumbler all day. This morning I emptied a bit of the slurry out as it was a bit thick and because I thought I had reached the end of the road with the experiment, I added about half a teaspoon of Tin Oxide, tonight things are starting to happen, they are starting to shine. I wonder If I jumped the gun in pronouncing the experiment over, or is a teeny tiny bit of Tin is doing the trick?
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jamesp
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Post by jamesp on Jan 27, 2016 6:38:42 GMT -5
Cooler here today, so ran the tumbler all day. This morning I emptied a bit of the slurry out as it was a bit thick and because I thought I had reached the end of the road with the experiment, I added about half a teaspoon of Tin Oxide, tonight things are starting to happen, they are starting to shine. I wonder If I jumped the gun in pronouncing the experiment over, or is a teeny tiny bit of Tin is doing the trick? I run AO 500 right thru till Mohs 7 rocks are polished. 4 days. Have added AO 14,000 polish at beginning of day 3 and had the same polish after 3 days as I did 4 days of AO 500. Never had a problem adding polish to broken down AO 500. I think you would have to run the kaolin on a longish trial to find out. Only way to know. AO 500 improves daily till the end of day 4 and then little change occurs(in my vibe). Regardless, if your kaolin got you thru pre-polish mission accomplished. You may not get rain in Australia like we do here in Georgia. Here, the rains wash a very fine silt into kaolin pits. We used to jump in the ponds where the silt collects quite a few feet deep. My guess would be that that silt is free of large particles in many situations. The finest of the finest particles. Planning on getting a couple of 5 gallon buckets of that silt next trip to the pits. May do well as a fine polish. See the silt in the water that has washed off the slopes
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Post by pauls on Jan 28, 2016 16:10:15 GMT -5
Still going still getting shinier, though its fairly slow. The protruding bits of agate are really shiny the flat spots not so much, more time would probably eventually do it.
I would say if you are looking for something to use to thicken up your slurry in the final stages and prepolish then this is a good option, due to the variability of the clay probably not so much for polishing. I have shown that clay from this pit will polish hard stones, eventually, no saying what other Kaolin sources are like.
Paul
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jamesp
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Post by jamesp on Jan 29, 2016 6:00:47 GMT -5
Still going still getting shinier, though its fairly slow. The protruding bits of agate are really shiny the flat spots not so much, more time would probably eventually do it. I would say if you are looking for something to use to thicken up your slurry in the final stages and prepolish then this is a good option, due to the variability of the clay probably not so much for polishing. I have shown that clay from this pit will polish hard stones, eventually, no saying what other Kaolin sources are like. Paul I do use the back yard red clay for a slurry thickener for a SiC 30 grit coarse grind in the rotary pauls. It is just kaolin with 5-10% iron oxide making it red but it is high in alum ox. After 2 weeks the SiC has completely broken down and it appears the clay has given a slight shine. As if tumbling with a fine grit and a coarse grit at the same time. Not a normal practice mixing abrasives. Small abrasives break down much slower that coarse abrasives, like polish can be reused because it is stubborn to break down. So tumbling with a coarse and a fine abrasive at the same is probably doable. After shaping a batch of rocks with 6-7 coarse grit changes I once let the last 30 grit charge and the clay run for 4 weeks in the rotary and had a decent shine. In that 4 weeks I think all the sub standard clay particles were beat down. AO 1000 in the vibe polished them in a hurry. Proving the long 4 weeks had them close to polish ready. Most efficient labor wise is 2 weeks with the last charge of SiC 30 with clay and then 4 days in AO 500 in the vibe to a polish. That has been repeatable. The 220 step totally redundant. IMO, the long run in the tumbler is better at crushing large particles than doing multiple steps involving clean outs where you may miss larger particles. i.e. Let the tumbler do the work. It works 24 hours a day and is efficient at breaking grit down.
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