jamesp
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Post by jamesp on Jan 31, 2017 20:06:42 GMT -5
I use 1/2 cup SiC 30 grit every day or two on 8 pounds rock in rotary. Lots of grit.
Why ?? Because it breaks down. Part of the time it is broken down and ineffective. Half the time it is probably less than 60 grit.
What if:
What if you had say 1/8 cup of 30 grit diamonds in barrel and they never break down which I doubt they will because they are likely indestructible in a rotary. That would mean you have full time dead sharp 30 grit cutting your rocks 100% of the time. No 100 grit, no 200 grit, but full time 30 grit. Makes a big difference.
Will that small amount last for weeks(or months, or forever). I think they will. Diamonds are tough, they don't play. You could just put water in the barrel to dilute the slurry and let the heavy diamonds settle to the bottom. Carefully pour off the top water leaving the diamonds. Add more fresh water and shake the barrel to thin the slurry and again pour the top water off. Till slurry is acceptably thin. Crank her back up.
Question is, will 1/8 cup(synthetic diamonds expensive) coat the rocks enough to effectively grind ? -OR- what is the minimum amount-1/4 cup ? 1/16 cup ?
If 1/4 cup or however much is needed of sharp 30 grit diamonds and they last last 100-200 coarse grinds then it is darn sure worth hassling with recapturing them after the coarse grind. They are in he barrel, you just have to be careful recapturing them.
And if they do not break down your rocks will have serious scratches that would probably require an SiC 30 run w/breakdown to get rid of the deep scratches. But if those diamonds shape your rocks 5 times faster who cares.
A cup is 16 tablespoons. So 4 tablespoons would be 1/4 cup for 8 pounds rock. A 4 inch diamond pad has 30 carats diamond. Diamond weighs 3.5 grams per milliliter. A tablespoon is 15 milliliters. So a tablespoon of diamonds weighs 3.5 X 15 = 52 grams. 1 gram = 5 carats. So one diamond pad has 30/5 = 6 grams of diamonds. 9 pads has a tablespoon of diamonds. 36 pads would be a 1/4 cup of diamonds. 36 pads cost $1.6 X 36 = $58.
You see where I am going with this. If a 1/4 cup diamonds could be had for say $10 and they last forever...and assuming some loss at clean outs....diamonds would be cheap replacement for SiC.
Food for thought.
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Deleted
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Post by Deleted on Jan 31, 2017 20:59:03 GMT -5
I have wanted to buy a kg of diamond grit to test exactly this.
Gotta have a tumbler first!
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jamesp
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Post by jamesp on Feb 1, 2017 0:32:51 GMT -5
A whole kilo ? How about 1000 carats ? ~1/2 pound. May last a long time.
All you have to do is prefect your separation process.
1/4 screen to catch tumbles over a white pan. Rinse well over pan. Pour water off and collect small stuff. Reuse, diamonds will be in there with some trash. Trash won't hurt nothing.
If the rubber in those pads break down in the tumbler I can recapture the 50 grit. 50 is a bit on the small side to see with the eye. 30 easier.
Also, if you had a vibe hopper that could handle the sharp diamonds it may grind rocks fast. 30 grit SiC lasts about an hour or two in my vibe. It is like 60 grit in an hour. What if diamonds lasted for years in the vibe. Vibes are super abrasive crushers. You have a very short time period to get large grit to grind rocks. And vibes are very effective with much less grit. You could probably put a 12 mil plastic bag in the vibe to protect it. Or an EPDM bag. Replaceable PVC pipe..
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ChicagoDave
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Post by ChicagoDave on Feb 1, 2017 8:00:49 GMT -5
Any particular ebay vendors you've worked with before that sell this? I'll run the experiment and see what happens.
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Post by captbob on Feb 1, 2017 9:06:15 GMT -5
You don't think the diamond grit would wear down?
"That would mean you have full time dead sharp 30 grit cutting your rocks 100% of the time.
I'm guessing that they would wear and round, giving you less life than one might imagine.
SiC grit is around a 9 on the Mohs I believe. How long does it last against the rocks? Diamond grit would be a 10 on the scale. Tough and hard! Agreed.
But... you are still pitting something the size of a grain of coarse salt against rocks, Often quite large rocks. Big vs little - hard vs very hard - who wins
Tiny diamonds being smashed by hard rocks hour after hour, day after day. My money is on the rocks & time.
For many here, clean out day is not on their favorite things to do list. Too much work? Heck, sounds like a lot of folks don't even want to use plastic beads because they are too much work. Your diamond retention procedure would have such folk pulling out their hair.
I do look forward to your experimentation with diamond grit. You sir are the man for the job! Hope it works. If nothing else it should prove to be interesting and entertaining.
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jamesp
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Post by jamesp on Feb 1, 2017 9:14:05 GMT -5
Any particular ebay vendors you've worked with before that sell this? I'll run the experiment and see what happens. I do not. You MUST have sharp diamonds. So communication is important. I bought a packet of 25 grit crystals from China using Aliexpress. Just to tinker with them. They seem way to smooth to use for tumbling. Certain that Ebay has suppliers for 'sharp' diamonds. I think the sharp diamonds are simply crushed crystals. Probably crushed defective crystals. Or made with another process. Crushed/sharp diamonds much cheaper. Let me look at Ebay and see what they got Dave. Ebay is way safer than Alibaba and Aliexpress. American Express senses fraud half the time I purchase through Aliexpress. Sharp(perhaps crushed) diamonds: Round crystals, these will NOT cut rocks in a tumbler as well as sharp:
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jamesp
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Post by jamesp on Feb 1, 2017 9:41:35 GMT -5
You don't think the diamond grit would wear down? " That would mean you have full time dead sharp 30 grit cutting your rocks 100% of the time.I'm guessing that they would wear and round, giving you less life than one might imagine. SiC grit is around a 9 on the Mohs I believe. How long does it last against the rocks? Diamond grit would be a 10 on the scale. Tough and hard! Agreed. But... you are still pitting something the size of a grain of coarse salt against rocks, Often quite large rocks. Big vs little - hard vs very hard - who wins Tiny diamonds being smashed by hard rocks hour after hour, day after day. My money is on the rocks & time. For many here, clean out day is not on their favorite things to do list. Too much work? Heck, sounds like a lot of folks don't even want to use plastic beads because they are too much work. Your diamond retention procedure would have such folk pulling out their hair. I do look forward to your experimentation with diamond grit. You sir are the man for the job! Hope it works. If nothing else it should prove to be interesting and entertaining. Diamond is funny Bob. MOHS scale is very deceptive. Scale is 1 to 10. Yes, diamond is a 10 but four times harder that Mohs 9 ruby. But many times tougher. SiC shatters in a tumbler. It really does not 'wear'. No way a Mohs 7 agate can scratch SiC. Will never ever happen. If Sic did not shatter it would cut and cut. But it is like glass-brittle. Diamond will take a mild hammer blow and not crack. It is almost like metal, mechanical term is 'tough'. Example: King Kong grinder-The matrix wears and releases/exposes the diamonds. But from what I understand the diamonds do not dull or break down even under those extreme pressures. They just fall out of the binding matrix and new diamonds are exposed. Another example: Diamond faced oil drilling bits: They dig 5000 to 10,000 feet thru solid rock. Darn diamonds take this abuse. Don't think a tumbler is in any form a comparison to drilling. Many drill rigs use a drilling action and powerful hydraulic impact devices. They use diamond tips. As far as clean outs. Don't. Just pour some water in the barrel and and drain the top off a few times till slurry is thinned. Shake barrel a bit between water additions. The heavy diamonds will settle lower and not pour out. Yes, at final clean out care must be taken to recapture the diamonds. A rock screen and a pan. Just like capturing gold.
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jamesp
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Post by jamesp on Feb 1, 2017 9:45:54 GMT -5
Vicker scale. But still does not take into account toughness.
Vicker Scale of Actual Hardness: 1: Talc 3: Gypsum 9:Calcite 21: Fluorite 48: Apatite 72: Orthoclase 100: Quartz 200: Topaz 400: Corundum 1600: Diamond
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jamesp
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Post by jamesp on Feb 1, 2017 10:29:43 GMT -5
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Deleted
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Post by Deleted on Feb 1, 2017 18:20:25 GMT -5
I'm in agreement that sharp seems better.
Allow me to explore alternative possibility.
Sharp tips are least tough. Makeing prone to rounding. I don't think rounding is an issue. Plus, starting round may be ideal. Allow me to explain.
In your rather amazing images of tumbled stones. I see rocks that lack scratches but instead exhibit pits.
This seems to indicate that when the stone "falls" onto one under itself the grit is trapped between and cuts that divot we see in your pics. Rounded stones are naturally tougher for their shape. They may literally last forever in a tumbler.
It could be SiC is better in this arrangement. Simply due to the fracture that happens may literally explode into that divot.
Just spit balling. Nothing conclusive. Just ideas. Wish I could join in the hunt.
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Post by melhill1659 on Feb 1, 2017 19:04:43 GMT -5
Ok so I'm not mechanically inclined nor a math major. I need to pop a bc and take a nap now...
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jamesp
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Post by jamesp on Feb 1, 2017 19:06:33 GMT -5
I'm in agreement that sharp seems better. Allow me to explore alternative possibility. Sharp tips are least tough. Makeing prone to rounding. I don't think rounding is an issue. Plus, starting round may be ideal. Allow me to explain. In your rather amazing images of tumbled stones. I see rocks that lack scratches but instead exhibit pits. This seems to indicate that when the stone "falls" onto one under itself the grit is trapped between and cuts that divot we see in your pics. Rounded stones are naturally tougher for their shape. They may literally last forever in a tumbler. It could be SiC is better in this arrangement. Simply due to the fracture that happens may literally explode into that divot. Just spit balling. Nothing conclusive. Just ideas. Wish I could join in the hunt. The first roll with the pads should jar diamonds out of the pads. Time will tell if they get dull or crack. Rate of development of dirty slurry should be the judging factor. I hear you about the pits. IMO, the grit is rolling between the rocks to do the perfectly pitted texture. Mud slurry reduced bouncing to about zero and seems all movement is a sliding action. Vicker's test. Where a precut tip is forced into a rock and the depth of divot is measured. Is it a deformation or a fractured hole in hard rock, no idea. No idea if blunt is better than sharp. Lot of theory. Hardness and toughness of materials is a fine line. Under all conditions I think grit staying full size and sharp has to be best situation.
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Deleted
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Post by Deleted on Feb 1, 2017 19:10:13 GMT -5
Jim, I love these brainstorming sessions. I learn so much from you. And sometimes I get to be devils advocate and ideas just flow. It is fun. Thank you! jamesp
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jamesp
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Post by jamesp on Feb 1, 2017 19:11:04 GMT -5
Ok so I'm not mechanically inclined nor a math major. I need to pop a bc and take a nap now... Math OD ? Only a bc ?
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jamesp
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Post by jamesp on Feb 1, 2017 19:11:55 GMT -5
Jim, I love these brainstorming sessions. I learn so much from you. And sometimes I get to be devils advocate and ideas just flow. It is fun. Thank you! jamespEasily amused ? Tumbling complicated, never know.
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Deleted
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Post by Deleted on Feb 1, 2017 19:17:55 GMT -5
I just love thought experiments.
I dont have the luxury of getting my hands dirty. But, I do have lots of windshield time to grind out these little thought experiments. Am pleased you let me play in your playground.
I am at a lake in the middle of the Mojave Desert (google Helendale, Ca) and there are anout 5000 sea gulls 50 yards from my car. I'm waiting for my trainee to get here so we can go sell some windows.
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Deleted
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Post by Deleted on Feb 1, 2017 21:34:41 GMT -5
Ok so I'm not mechanically inclined nor a math major. I need to pop a bc and take a nap now... Math OD ? Only a bc ? BC?
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Post by melhill1659 on Feb 1, 2017 21:46:29 GMT -5
BC powder, it's basically aspirin in powder form. That was a joke by the way. Can't take the stuff 😂
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jamesp
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Post by jamesp on Feb 2, 2017 5:50:46 GMT -5
Southern mothers were about to wear you out when she mentioned a bc. "Y'all are going to make me take a nerve pill !!" "If I have to take a bc !!" Short for "I'm getting ready to kick you kidz's arses" Standard deep southern colloquial at it's finest. Gotta explain this stuff to them there Calyfornyns melhill1659. Don't let Scott fool ya, he is a whole lot smarter than he looks.
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jamesp
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Post by jamesp on Feb 2, 2017 6:04:46 GMT -5
I just love thought experiments. I dont have the luxury of getting my hands dirty. But, I do have lots of windshield time to grind out these little thought experiments. Am pleased you let me play in your playground. I am at a lake in the middle of the Mojave Desert (google Helendale, Ca) and there are anout 5000 sea gulls 50 yards from my car. I'm waiting for my trainee to get here so we can go sell some windows.
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