jamesp
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Post by jamesp on Dec 31, 2014 4:35:16 GMT -5
This product is much softer the aluminum oxide. Testing it in the rotary on obsidian as the next step after AO 220 in the rotary starting yesterday.
Hoping that it will sand away the 220 surface and break down to a fine polish easier and transfer it to the obsidian in a rotary.
Unlike vibes, the rotary is slow to break down grit. Maybe this softer abrasive will break down quicker for the rotary and still cut rock well.
Plan to try it in the vibe to see if it will reduce those long runs in 500 and 1000 on obsidian and other softer rocks. The only reason for long runs in a vibe to polish softer rocks must have to do with softer rocks are slower to break hard grit down. Where as agate is quick to break the hard grits down and polishes much faster. Guessing that the large doses of ceramic media assist in breaking the hard grit down when tumbling soft rocks. As well a serving as padding. Try tumbling obsidian without media in a rotary using aluminum oxide, good luck. That's my theory any way. Just putting it out there. Will see.
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jamesp
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Post by jamesp on Dec 31, 2014 14:17:52 GMT -5
This stuff is dead clear. Has no color. 24 hours and 220 finish not removed, but big impact in rotary. Started a load of 500 obsidian in the vibe this morn. Same thing, clear.
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Post by captbob on Dec 31, 2014 15:53:38 GMT -5
Once again, I absolutely don't get it. I do understand that you simply like to experiment, but what is your goal? Why do you want a softer abrasive or for it to break down quicker? Each grit / polish has a job to do. And, one needs to allow each the time to do it's job. You wrote: " Plan to try it in the vibe to see if it will reduce those long runs in 500 and 1000 on obsidian and other softer rocks." So, going from 220 to 500/1000 requires long runs to remove 220 scratches? Either allow the 220 to run longer or use a 320 as an intermediate step in between 220 & 500. (I would just allow the 220 time to do it's work.) MY opinion is that the majority of your challenges are due to trying to rush the processes. I really don't understand what an extra day here and there might matter if it means that you don't have to continually go back and rerun grits to fix or improve the run. It's not like you can be trying to come up with some perfect formula, because each load of rock is different and no "perfect formula" will ever exist. I understand the vibe and speeding up the end stages over the time a rotary would take. But, even in a vibe each grit/polish must be allowed it's time. How much time do you figure on saving? (again, just trying to understand) I was rereading the Instructions for vibe tumblers.... thread the other day and connrock speaking of going from a rotary to a vibe to finish wrote - 99.999% of all flaws should be gone before you use the vibe to continue the polishing process. I just sat and looked at that sentence for several moments. Might be the best thing I've seen written here. My intent is not to be obstinate nor obtuse, just
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jamesp
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Post by jamesp on Dec 31, 2014 18:52:38 GMT -5
Once again, I absolutely don't get it. I do understand that you simply like to experiment, but what is your goal? Why do you want a softer abrasive or for it to break down quicker? Each grit / polish has a job to do. And, one needs to allow each the time to do it's job. You wrote: " Plan to try it in the vibe to see if it will reduce those long runs in 500 and 1000 on obsidian and other softer rocks." So, going from 220 to 500/1000 requires long runs to remove 220 scratches? Either allow the 220 to run longer or use a 320 as an intermediate step in between 220 & 500. (I would just allow the 220 time to do it's work.) MY opinion is that the majority of your challenges are due to trying to rush the processes. I really don't understand what an extra day here and there might matter if it means that you don't have to continually go back and rerun grits to fix or improve the run. It's not like you can be trying to come up with some perfect formula, because each load of rock is different and no "perfect formula" will ever exist. I understand the vibe and speeding up the end stages over the time a rotary would take. But, even in a vibe each grit/polish must be allowed it's time. How much time do you figure on saving? (again, just trying to understand) I was rereading the Instructions for vibe tumblers.... thread the other day and connrock speaking of going from a rotary to a vibe to finish wrote - 99.999% of all flaws should be gone before you use the vibe to continue the polishing process. I just sat and looked at that sentence for several moments. Might be the best thing I've seen written here. My intent is not to be obstinate nor obtuse, just Thanks for asking captbob. Let me play devil's advocate and ask, "would you use diamond powder on talc?". Would the talc ever breakdown the diamond ? This softer grit is only intended on being used on softer stones. Name obsidian. Hard materials need hard grit and soft materials usually do better with softer grit. Especially if you are depending on the grit to break down to make a smooth transition from one grit to the next. In the case of softer materials, you will may be waiting on an overly hard grit to break down. Solution may be to use a softer grit on softer materials. AO, SiC, Cerium Ox, Tin Ox are all pretty darn hard. Not many people are out there tumbling obsidian with garnet or plain quartz grit. Case in point-obsidian must run longer in AO 500, 1000 and polish longer than mohs 7 quartz in the vibe to get a polish using AO. Why ? Suspicious that the soft obsidian can not break grit down as fast as agate. So maybe time and energy is being wasted. It may or may not be that Mohs 9 grit is slower to break down with mohs 5.5 obsidian. But it is worth a try to use mohs 7 grit. If the softer grit gets the job done faster then all the better. Not rushing, just looking for a possibly more efficient way. Add the issue of a rotary tumbler being slower to break grit down, softer grit may help. Timing has a lot to do with all this. If you are expected to run obsidian 3 days on AO 500 in a vibe and after 1 day the AO500 has done it's finish, great. But is it taking 2 more days for the grit to break down? Is that what is happening ? Don't know. But it could. On the other hand, it may take the softer abrasive 6 days to put a 500 finish on the obsidian. That is possible too. Because it is softer, it may take a long time. That's not good. Who knows ? Lots of questions so try the softer grit. I just resent having to run the vibe longer to get a polish on obsidian than quartz. It is illogical. Makes no sense. Somethings awry. So that is the reasoning captbob. Always had good fortune trying new schnit. Has paid good dividends. Also got a big pile of obsidian to tumble, along w/some other soft rocks.
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Deleted
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Post by Deleted on Dec 31, 2014 21:34:06 GMT -5
captbobKeep in mind he is running glass and agate/corals thru the same processes. His corals come out looking like wet ice. The obsidian not so much. I see here he has noticed obsidians go fast in the early stages but slow down after 200/220, in his system. Trying a softer grit seems to make total sense to solve this specific problem in this specific material. What if he finds that the process is improved by this never before tried method? Many others will benefit. Have you been able to polish obsidian in your tumbler system? Sorry, mine is only worth
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Post by captbob on Dec 31, 2014 23:37:48 GMT -5
Thank you James for explaining what you are trying here. It must have been difficult for you to type slow enough for me to finally understand your goal. Makes sense now. I still think you are rushing things, but I see the purpose of looking for a "softer" grit and the possibility of speeding up the process if it works. Good on ya. Looking forward to your further efforts and conclusions. Scott... where did I miss these "wet ice" corals, can you link the thread please? I've seen some of James' Rios that "wet ice" would be a good name for, and some very nice and interesting looking corals. Just must have missed some corals tho. He has done a great job on coral I have seen, but I don't know if that material can take a shine that I would consider wet ice. On that note, this batch of obsidian that Chuck - Drummond Island Rocks, posted awhile back I would give the wet ice stamp. These may be the finest obsidian I have ever seen. Wonder how he did it. Figure a rotary then a vibe, but what grits and durations? Doubt it was anything out of the ordinary. forum.rocktumblinghobby.com/thread/68028/10-11-obsidian-batchWhatever he did worked. In spades! You asked if I have been able to polish obsidian in my tumbler system. I'm working on my very first obsidian batch right now. I have some set out after 120/220 waiting on more to fill a barrel to move on. And some finishing up a LONG run in 60/90. This is what I started with which is why it has takes so very long. It may well take me until March to finish this obsidian, but I'll bet ya a dollar that it's darn near as nice as Chuck's by the time I consider it done. (I aim high!) Actually, I think it should go pretty fast once this last 60/90 barrel is ready to move on. The pieces I have pulled aside out of 120/220 were only in there a couple weeks before they were ready to move on. 60/90 is where all the real work happens, the rest of the process should move right along. Hopefully! 'Cuz I'm about over mahogany obsidian - too boring looking. Wish I had used snowflake. Will probably break the obsidian up into a few smaller batches after 1000 to try different polishes. That is an experiment that I could run and share the results of. Exact same obsidian in 3 or 4 different polishes. Would interest me anyway. Happy New Year!
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jamesp
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Post by jamesp on Jan 1, 2015 3:24:49 GMT -5
Had a hard time finding garnet or quartz abrasive in the 500-1000 range. Aluminum oxide replaced garnet abrasives. And it is used on sand paper and grinding wheels almost exclusively. No problem for many applications. You are sanding a piece of furniture from 60 to 180 to 220 to 400 and possibly 600. No grit break down, just stepping thru the grits.
Rock tumbling depends on grit breaking down. It is a unique situation. Most tumble agates and quartz. They do well with hard abrasives.
So I googled softer polishes and had a hard time finding any. Finally found a quartz silica by product. It is some where in the 400-900 size, guessing. A vibe can easily take a rock to a wet shine with that size grit. Hoping that the rotary will break it down fast on soft rocks too.
So it is running in the rotary and the vibe on obsidian for a couple of days now. The vibe should have results here in the next day or two. If not, then its back to the AO.
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Post by connrock on Jan 1, 2015 8:55:52 GMT -5
captbob,,, I wrote a lot of things here and my intent was (for the most part) written to help newbies with their tumbling.Many buy a tumbler, and think that if they follow the manufacturers tumbling instructions,they'll have polished rocks in no time at all. They go through the process and are very disappointed in the results. They may have started out trying to tumble something that is next to impossible to polish,,,,like soft beach stones they and their families collected during a vacation,etc,etc,,,or maybe they just followed the instructions that came with their tumbler??? I any case,,,the most common error made is not roughing their rocks long enough.They are very impatient yet want to see perfect results! This is why I try to instill in their heads that 99.999% of all flaws HAVE to be removed in the roughing stage before going on to the next stages. If they don't do this it's just like restoring an old car and painting over all the dents and rust!
connrock
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Post by captbob on Jan 1, 2015 10:41:08 GMT -5
I understood what you wrote and why. That statement really isn't limited to when going from a rotary to a vibe either. I was struck by it possibly because it so mirrors my thinking. Prolly sittin' there thinkin' "I should have written that!" Not like I can go around saying something I wrote is the "best thing I've seen written here" - shouldn't anyway!
Granted, the imperfection removal percentage stated may be a tad high, but you are getting to the heart and soul of tumbling with that statement. Remove imperfections, polish, move on. How critical a person decides to be on the "removing imperfections" part is up to each individual. But, with tumbling, as with so many things in life; ya get what ya pay for. Different folks are happy with different levels of success - not just involving tumbling.
Pretty sure I've derailed this thread enough. Time to sit back and watch again.
Happy New Year ya'll
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jamesp
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Post by jamesp on Jan 1, 2015 13:59:57 GMT -5
Derailaway. Good info. Happy New Year captbob
Looks like the vibe broke the soft grit down to nothing after 2 days, maybe in one day. Started to polish the high spots, and left pits from 500 on the obsidian. So more quartz grit added in an attempt to remove the 500 pits in the obsidian. Not a clean out, just added more, easy. Looks like mohs 7 grit is on the soft side for the mohs 5.5 obsidian. However, it did remove the 500 pits from the mohs 4 fluorite. So mohs 7 grit on a mohs 4 rock may do fine. Mohs 9 AO works good on mohs 7 quartz and agate in finish mode. So 2+ mohs points may do fine. Mohs scale not linear though, so the relative hardnesses can be very deceptive. A good example is diamond at mohs 10, ruby is mohs 9, but diamond many times harder than ruby. Will try this grit on calcite, celestite, onyx, marble, unakite, some heated rhyolites, felspar.
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jamesp
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Post by jamesp on Jan 2, 2015 6:21:29 GMT -5
Day 2, soft grit, vibe turned down slow. Trying to remove 500 grit finish. Grit has broken down, but too fine to remove 500 finish. May have to add grit daily to grind 500 finish, since it is breaking down to polish sometime after 24 hours. Left stone w/virgin 500 finish, middle stone after 1 day with no reflection, right stone showing signs of polish on high spots telling grit breaking down even with gentle vibe setting. Lower stones started with same 500 finish, 4 days in AO 1000 and 2 days in AO 14,000 at gentle vibe setting So it looks like there is no gain in using the soft grit on obsidian, but may be fine for mohs 4 stones at gentle vibe settings. Added fresh grit yesterday to see if 500 pits are removed on day 3. Likely to take at least 4 days to prep stone for 14,000. So no gain over the AO 1000 4 day run for obsidian. But the grit did break down, that may come in handy for mohs 3-mohs 4 material, a goal I am pursuing. Not bad for 50 cent/pound abrasive. Not an issue for the vibe, but saves money on the hungry rotary.
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Post by connrock on Jan 2, 2015 9:41:17 GMT -5
It looks like this answers the question of softer grit v obsidian James.We'd never known if you didn't try it,,,thanks. Mohs scale diamond/corundum,,,,I remember reading somewhere that diamond (10) is 10 times harder then corundum(ruby sapphire) (9) but I don't recall where I read that. This leads me to believe that there may be quite a bit of difference in hardness in (for example) a 7 or 7 1/2 on Mohs scale?
I also read (somewhere) that when tumbling obsidian it should all come from the same area as it's hardness differs from one location to another.I posted this some time ago and was (more or less) called a buffoon! LOL Considering that obsidian can be a 5 or 5.5 in hardness and that Mohs scale is not linear,,,,this 1/2 difference in hardness may enter into the equation when trying to tumble obsidian??? Food for thought??? connrock
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brent3369
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Post by brent3369 on Jan 2, 2015 10:11:34 GMT -5
That is a nice shine all right Where does chrome oxide fall as far as hardness compared to other polishes?
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jamesp
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Post by jamesp on Jan 2, 2015 10:36:09 GMT -5
It looks like this answers the question of softer grit v obsidian James.We'd never known if you didn't try it,,,thanks. Mohs scale diamond/corundum,,,,I remember reading somewhere that diamond (10) is 10 times harder then corundum(ruby sapphire) (9) but I don't recall where I read that. This leads me to believe that there may be quite a bit of difference in hardness in (for example) a 7 or 7 1/2 on Mohs scale? I also read (somewhere) that when tumbling obsidian it should all come from the same area as it's hardness differs from one location to another.I posted this some time ago and was (more or less) called a buffoon! LOL Considering that obsidian can be a 5 or 5.5 in hardness and that Mohs scale is not linear,,,,this 1/2 difference in hardness may enter into the equation when trying to tumble obsidian??? Food for thought??? connrock The mahogany sheen obsidian is the hardest I have. the other 4 are sort of in order of being softer, I don't know the names of them. But the softer ones bruise a lot easier when all run together. You are totally correct. Like different rocks. Not a buffon, a genius . The 5 to 5.5 is apparently a lot. But glass ain't no different, many hardnesses in that stuff. I can tell with the mix of glass fillers, some polish, some don't. Someone jumped me about saying coral is 7.5, he can jump all he wants but the shnitt is harder, no doubt. Lot a cab guys will tell you some agates harder than others. Yep, diamond is like 10 times harder than corundum. The mohs scale is all over the place. A controlled grind test it about the best way to compare hardness. I may mix AO 1000 with this grit. To remove the 500 and then feather out in harmony with this softer grit. Am looking at mohs 7.5-8 grit for obsidian. Still fooling w/softer, or just starting. Another grit is 7.5 and rounds to very smooth tiny balls. That one is most interesting for obsidian. This grit petered out too soon with the obsidian. But the real problem is that it is too fine to be a 500 transition grit. Had it been a bit coarser it may have removed the 500 marks and carried on to a quick polish due to it's quick break down.
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jamesp
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Post by jamesp on Jan 2, 2015 10:40:21 GMT -5
That is a nice shine all right Where does chrome oxide fall as far as hardness compared to other polishes? Having difficulty on finding dang hardness comparisons for grit Brent. I think tin oxide is one of the softer ones. It is known for doing well w/softer rocks. Do not know where chrome oxide falls, but have been researching that one.
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Fossilman
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Post by Fossilman on Jan 2, 2015 11:02:47 GMT -5
If it wasn't for our past population experimenting,we wouldn't be as far as we are in this world today..........GIT R DONE....LOL
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brent3369
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Post by brent3369 on Jan 2, 2015 11:24:53 GMT -5
I started in this hobby with chrome oxide for everything. I am running it in the vibe right now and what I'm thinking is that I need to eliminate the course operation from the dolomite and just go with the finer grits. The dolomite I can polish on a buffing wheel straight from raw...lol. It does take an awesome shine, so I will figure out the tumbling thing with it.
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jamesp
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Post by jamesp on Jan 2, 2015 15:26:20 GMT -5
I started in this hobby with chrome oxide for everything. I am running it in the vibe right now and what I'm thinking is that I need to eliminate the course operation from the dolomite and just go with the finer grits. The dolomite I can polish on a buffing wheel straight from raw...lol. It does take an awesome shine, so I will figure out the tumbling thing with it. You may have to vibe tumble that one with corn cob or rice hull padding. I have some kona dolomite I need to try. I will post my attempt.
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39don
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Post by 39don on Jan 4, 2015 0:42:37 GMT -5
It looks like this answers the question of softer grit v obsidian James.We'd never known if you didn't try it,,,thanks. Mohs scale diamond/corundum,,,,I remember reading somewhere that diamond (10) is 10 times harder then corundum(ruby sapphire) (9) but I don't recall where I read that. This leads me to believe that there may be quite a bit of difference in hardness in (for example) a 7 or 7 1/2 on Mohs scale? I also read (somewhere) that when tumbling obsidian it should all come from the same area as it's hardness differs from one location to another.I posted this some time ago and was (more or less) called a buffoon! LOL Considering that obsidian can be a 5 or 5.5 in hardness and that Mohs scale is not linear,,,,this 1/2 difference in hardness may enter into the equation when trying to tumble obsidian??? Food for thought??? connrock You are correct. It's according to which hardness scale you are using ie, a 10 point or a 100 point. 10 point scale = ruby and sapphire are a 9 and diamond is 10....... 100 point scale = ruby and sapphire are a 2 and diamond is 100......... The only thing harder than ruby and sapphire is man made boron carbide and it is 27 on the 100 point scale. I have the 100 point scale in one of my rock/gem books but it's too late tonight for me to start looking. I'll try to locate it tomorrow. I did find a Moh's scale = 10 point scale.... hardness of the mineral The hardness of the mineral is measured for comparison with the represented of the ten classes of the Mohs scale (Friedrich Mohs, German mineralogist, Germode 29/1/1773 - Agordo 29/ 9/ 11839). In her a material of a certain class is grazed from those of the following classes and grazes all those of the preceding classes. In the absolute scale of the hardness (of Rosiwal), this is express in resistance to the abrasion measured in proofs from laboratory and attributing to the corindone the value 1000. Also for the Knoop scale the values of hardness are absolute, and they depend on the depth of the signs engraved on the mineral one from a special utensil with point of diamond, with which a force standard is practiced Mohs Rosiwal and Knoop scale mineral MOHS talc or graphite--------- 1 gypsum or sulfur--------- 2 calcite------------------ 3 fluorite----------------- 4 apatite------------------ 5 orthoclase or feldespar-- 6 quartz------------------- 7 topaz-------------------- 8 corundum----------------- 9 diamond------------------ 10 mineral ROSIWAL talc or graphite-----------------------0.03 gypsum or sulfur-----------------------1.25 calcite--------------------------------4.5 fluorite-------------------------------5 apatite--------------------------------6.5 orthoclase or feldespar----------------37 quartz---------------------------------120 topaz----------------------------------175 corundum-------------------------------1000 diamond--------------------------------140000 mineral KNOOP talc or graphite----------------------1 gypsum or sulfur----------------------32 calcite-------------------------------135 fluorite------------------------------163 apatite-------------------------------430 orthoclase or feldespar---------------560 quartz--------------------------------820 topaz---------------------------------1340 corundum------------------------------1800 diamond-------------------------------7000
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jamesp
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Post by jamesp on Jan 4, 2015 7:25:24 GMT -5
Strange, the Viking instructions suggest rice hulls for padding when using other abrasives on obsidian. From some technical writing: "The high concentration of opaline silica on the outer surface of the rice hull also establishes the effective hardness of the rice hull at roughly the same values as reported for opal (6 on the Mohs scale). However, due to the presence of lignin within the rice hull, this hardness is tempered with flexibility and elasticity." Opailized rice hulls ?? LOL
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