jamesp
Cave Dweller
Member since October 2012
Posts: 36,553
|
Post by jamesp on May 29, 2017 23:23:44 GMT -5
I asked myself, how do I speed up the coarse grind on larger agate/Mohs 7 tumbles in the 1 to 2 inch range ?
felspar based clay slurry thickener- I add a heavy felspar based clay that increases the weight of the liquid in the tumbler. It simply increases the specific gravity of liquid to help 'float' the heavy coarse SiC particles to the rocks. A carrier. It is slick and increases lubrication. Increases cohesive forces between the rocks essentially sucking the rocks together increasing grind forces.
good application for clay slurry- Most of the time I want to run bigger rocks with no smalls. Bigger rocks being 1-2 inches. No 1/2" and 3/4" rocks. When running larger 1 to 2 inch rocks without smalls it can be difficult for a watery slurry to circulate the grit without thickener. If you have 50% smalls and 50% larger rocks by weight then 50% of the grit is likely being used on the small rocks. If you add grit weekly then it is going to take twice as long to do the bigger rocks-thinking 50% of grit goes to smalls, 50% of grit goes to large. If 100% of all contact grinding is big rock to big rock then all grit and all grinding is only done on the big rocks. Not shared with smalls. Best use of time and grit if bigger is your target. But a thick slurry best be maintained. That would be the primary coarse grind. Then add say 25% smalls during the last couple of coarse grit additions to reach divots and concave spots for the secondary coarse grind.
side note- If you coarse grind with 50% ceramic media and 50% rocks you are wasting grit and grind time on the ceramic media. Resources within your barrel being wasted.... That makes no sense. Why waste grit and time on ceramic media ? Never use ceramic media in coarse grind. It just beats your grit down, and wastes grinding space in your tumbler.
real world experience-
Without a doubt, 100% barrel fill of 1-2 inch agates/Mohs 7 rocks is a fast coarse grind. All resources within your barrel is dedicated to them. But tricky to do without a thicker than water slurry.
|
|
|
Post by coloradocliff on May 29, 2017 23:30:34 GMT -5
Be curious with what you come up with Jim. Don't know where you get the time for all you do but am looking forward to seeing how this goes and your final recipe. Have lots of big Montanas and no where to go..
|
|
jamesp
Cave Dweller
Member since October 2012
Posts: 36,553
|
Post by jamesp on May 29, 2017 23:31:05 GMT -5
Floating high in the heavy water of the salt rich Dead Sea
|
|
|
Post by coloradocliff on May 29, 2017 23:36:39 GMT -5
Maybe a high Viscosity slurry. Would oil carry the grit and cushion ?
|
|
jamesp
Cave Dweller
Member since October 2012
Posts: 36,553
|
Post by jamesp on May 29, 2017 23:40:09 GMT -5
Be curious with what you come up with Jim. Don't know where you get the time for all you do but am looking forward to seeing how this goes and your final recipe. Have lots of big Montanas and no where to go.. That is an old finding Cliff. Because I used to target collect semi-round corals in the 1-2 inch size and roll them. They were sorted by size on the river bar. Easy to fill a bucket with them. Using SiC 30 they were a fast coarse grind. A tough rock like river worn 1" to 2" Montana's would be a great candidate for dedicated grit/grind in a common 6-8 inch barrel. 3 inch ones may bruise if tumbled against each other in a common 6 to 8 inch barrel... After 2.5 inches those corals would have slight frosting on the edges.
|
|
|
Post by wigglinrocks on May 29, 2017 23:42:03 GMT -5
Your brainstorm makes perfect sense James .
|
|
|
Post by coloradocliff on May 29, 2017 23:43:59 GMT -5
Be curious with what you come up with Jim. Don't know where you get the time for all you do but am looking forward to seeing how this goes and your final recipe. Have lots of big Montanas and no where to go.. That is an old finding Cliff. Because I used to target collect semi-round corals in the 1-2 inch size and roll them. They were sorted by size on the river bar. Easy to fill a bucket with them. Using SiC 30 they were a fast coarse grind. A tough rock like river worn 1" to 2" Montana's would be a great candidate for dedicated grit/grind in a common 6-8 inch barrel. 3 inch ones may bruise if tumbled against each other in a common 6 to 8 inch barrel... After 2.5 inches those corals would have slight frosting on the edges. Thanks Jim.. Size is important.. The words men hate to hear most..
|
|
jamesp
Cave Dweller
Member since October 2012
Posts: 36,553
|
Post by jamesp on May 29, 2017 23:54:18 GMT -5
Maybe a high Viscosity slurry. Would oil carry the grit and cushion ? Look up 'colloidal slurry' Cliff. That is what industry uses. It is simply cheap felspar based clay. Felspar clay is by nature microscopic flat platelets(colloidal). It is mined here in Georgia on a nuclear scale. It is what is used in paint to keep the ink in suspension. Drop a 10 pound flat rock in a clear deep lake and watch how long it takes to sink. Drop a 10 pound round rock and watch it sink many times faster. Rotary tumblers do very well with colloidal slurry when using big SiC particles like SiC 8-16-30. Kaolin clay up close:
|
|
|
Post by coloradocliff on May 30, 2017 0:02:22 GMT -5
Interesting, surface area and friction for the different rate of descent? Kaolin clay is super slick and makes such nice fine pottery too.
|
|
jamesp
Cave Dweller
Member since October 2012
Posts: 36,553
|
Post by jamesp on May 30, 2017 0:32:51 GMT -5
Interesting, surface area and friction for the different rate of descent? Kaolin clay is super slick and makes such nice fine pottery too. Yep. And in a moving situation it never settles, stays suspended. Nothing like a full body immersion at the kaolin mine. Out of world experience.
|
|
|
Post by coloradocliff on May 30, 2017 0:52:09 GMT -5
Warm mud ummmm Throw a cement vibrater in on the other side of the pond of warm clay..Ahhhh What if it hardens in private parts? hehehehe
|
|
|
Post by youp50 on May 30, 2017 4:19:29 GMT -5
The clay holds the grit in suspension, only to be broken down when caught between the rocks.
I am unable to wrap my mind around the 'cohesive action sucking the rocks together'
Someone else posted, with graphs, how SIC was essentially broken down after three days. I also note that you ad grit daily. Balancing speed of grind with the desire to not waste grit I charge, ad grit for the following three days, run it out to a week and repeat until I am satisfied or discard the stone. Have you found clay to increase the time grit is 'useful'?
|
|
jamesp
Cave Dweller
Member since October 2012
Posts: 36,553
|
Post by jamesp on May 30, 2017 4:35:13 GMT -5
Warm mud ummmm Throw a cement vibrater in on the other side of the pond of warm clay..Ahhhh What if it hardens in private parts? hehehehe
|
|
jamesp
Cave Dweller
Member since October 2012
Posts: 36,553
|
Post by jamesp on May 30, 2017 5:09:58 GMT -5
The clay holds the grit in suspension, only to be broken down when caught between the rocks. I am unable to wrap my mind around the 'cohesive action sucking the rocks together' Someone else posted, with graphs, how SIC was essentially broken down after three days. I also note that you ad grit daily. Balancing speed of grind with the desire to not waste grit I charge, ad grit for the following three days, run it out to a week and repeat until I am satisfied or discard the stone. Have you found clay to increase the time grit is 'useful'? If in a hurry to coarse grind I will add SiC 30 for instance everyday for 5-6 days with a good viscosity clay slurry. After 5-6 days of adding daily I let it run 2-3 days just to make sure the 5-6 additions have broken down completely. Nothing was removed. Water is ADDED if the viscosity gets too high, and grit was added. So I end up with 5-6 grit additions and all grit reduced to nothing in 8-9 days. Then I do a clean out and refresh the tired clay. And back to the 5-6 daily addition thing and 2-3 day after run. Keep in mind the SiC 30 looks like this after 12 hours with the colloidal clay: This subject 'cohesive action sucking the rocks together'. 1) Put gravel in wheel barrow. Do it backward, add needed water to make concrete. Take hoe and rake water and gravel. Note ease to rake... Now add 92 pound bag of portland cement and rake till it has a nice thick slump. Note difficulty to rake.... -or- Look at concrete slump test. Why does the wet concrete stand in a cone shape ? You remove the slump cone and measure the drop in the standing concrete. So if you have a sticky/suction due to slurry in your tumbler barrel the grinding forces between the rocks increases. And the use of electricity goes up because the tumbler motor has to work harder to roll the barrel with sticky slurry. And the higher grind forces grinds rocks faster and breaks the grit down faster. Or you can simply stick two rocks together with a sticky slurry then that proves their is a suction force. Add that force many time per day and it adds up.
|
|
jamesp
Cave Dweller
Member since October 2012
Posts: 36,553
|
Post by jamesp on May 30, 2017 5:22:58 GMT -5
Have you found clay to increase the time grit is 'useful'? youp50- not. Adding grit daily just increases rate of using grit along with increased grind rate. The cohesive forces make a big impact on grind rate. It uses grit faster too. Push hard on sand paper it last less time than pushing softly on sand paper. One takes longer than the other but the end results probably about the same.
|
|
|
Post by youp50 on May 30, 2017 5:23:35 GMT -5
Thanks.
One of the things I have observed in daily adding of grit, is the same rocks tend to be on the open end of the barrel.
|
|
jamesp
Cave Dweller
Member since October 2012
Posts: 36,553
|
Post by jamesp on May 30, 2017 5:38:42 GMT -5
Thanks. One of the things I have observed in daily adding of grit, is the same rocks tend to be on the open end of the barrel. I do not recall that happening. But would notice as I try to remember the condition of those top rocks and slurry thickness every time barrel is opened. That trend would bother me. I would question the mixing action.
|
|
Wooferhound
Cave Dweller
Lortone QT66 and 3A
Member since December 2016
Posts: 1,432
|
Post by Wooferhound on May 30, 2017 7:57:35 GMT -5
I flip my barrels a coupla times everyday to keep that from happening.I started doing this when I noticed some marbles becoming Flat-Sided.
|
|
Fossilman
Cave Dweller
Member since January 2009
Posts: 20,709
|
Post by Fossilman on May 30, 2017 8:54:14 GMT -5
When I run agates,I usually put in one huge agate (Fist size),in the barrel and fill in around it with the small agate,different sizes and shapes.....Most of the time I never shape any rocks that I tumble.. (Mother nature made them that way),I will roll them that way,plus the slab ends,I just through them in too... Now yes,I go through the course grit fast and need that thicker slurry.... I like the method,you speak of James..... It would save on some coin.....
|
|
lookatthat
Cave Dweller
Whatever there is to be found.
Member since May 2017
Posts: 1,360
|
Post by lookatthat on May 30, 2017 11:23:13 GMT -5
Questions, questions, questions... Would a thick slurry cushion the rocks too much, negating some of the rock+grit+rock impact?
|
|