vance71975
freely admits to licking rocks
Member since September 2022
Posts: 760
|
Post by vance71975 on May 12, 2023 14:42:22 GMT -5
I know there is a point of too much grit. My question is, does it cut any faster if you add more than the 1 tablespoon per pound of rocks? Logically I would think more grit = more surface area contact = faster cutting. Not sure if that pans out in reality however. Like, would 4 tablespoons per lb cut faster than 1? Thoughts?
|
|
|
Post by tims on May 12, 2023 16:32:19 GMT -5
My guess is that at some point you'd get quite a bit of grit on grit action vs grit on rock, where your grit is breaking down by grinding against other grit instead of contact with the rocks. The standards for grit usage are always estimates but i assume over time they've been adopted for efficiency as well as efficacy, so going heavier on grit might get you faster grinding action at the cost of using much more grit, and i'd say give it a try if you don't mind burning through extra abrasive to test the theory. I'd also guess that using the "normal" amount of grit and just keeping it fresh would work faster than overloading grit, but this is just me pondering while being slightly distracted by the phrase grit on grit action.
|
|
vance71975
freely admits to licking rocks
Member since September 2022
Posts: 760
|
Post by vance71975 on May 12, 2023 21:15:31 GMT -5
My guess is that at some point you'd get quite a bit of grit on grit action vs grit on rock, where your grit is breaking down by grinding against other grit instead of contact with the rocks. The standards for grit usage are always estimates but i assume over time they've been adopted for efficiency as well as efficacy, so going heavier on grit might get you faster grinding action at the cost of using much more grit, and i'd say give it a try if you don't mind burning through extra abrasive to test the theory. I'd also guess that using the "normal" amount of grit and just keeping it fresh would work faster than overloading grit, but this is just me pondering while being slightly distracted by the phrase grit on grit action. Yep something to play with for sure. I have a bunch of Brown Agates that will be a pretty good test medinum, nice and hard and slow to cut!
|
|
dshanpnw
freely admits to licking rocks
Member since December 2020
Posts: 884
|
Post by dshanpnw on May 14, 2023 8:42:29 GMT -5
You always ask the good questions. I wonder about this almost every time I charge a barrel and lately I have been adding about two to three TBS extra per twelve pound barrel which is not that much more to make a difference and I really like trying to stick to the recommended 1 TBS per pound. I'm thinking that it depends mostly on type of rock and sizes of all the rocks.
|
|
|
Post by Starguy on May 14, 2023 10:21:09 GMT -5
…I'm thinking that it depends mostly on type of rock and sizes of all the rocks. That’s smart. Smaller rocks would have more surface area. More surface area would increase the contact plane between rocks, requiring a little more grit. Larger rocks would have less surface area in contact with each other. I think that standard tumbler recipes probably bracket the ideal quantity of grit. It’s hard to say how much playing around with the recipe could be done before the grind suffered. I don’t think about it too much anymore. Well, maybe a little when I’m holding a bag of tin oxide.
|
|
|
Post by Pat on May 14, 2023 10:39:55 GMT -5
Your logical question brings to mind the day my husband told me about “cooking” his TV dinner. Directions said something like cook for 30 minutes at 350 degrees.
He figured that was 15 minutes at 600 degrees. 😀 Hmmm….😄
|
|
|
Post by Rockoonz on May 14, 2023 14:37:30 GMT -5
What we discovered was that Lortone and Thumler also sell grit, and half of what they call out on their tumbling recipe seemed to make little or no noticable difference. Something a little more substantial like the big chunks-o-grit jamesp uses or the roughly 1/8 inch garnets Elizabeth uses for spacer/filler to help carry the grit into the nooks and crannys. You can also get the SiC pellets that are recommended for the Lot-O machines, basically action is what you're looking for more than anything.
|
|
vance71975
freely admits to licking rocks
Member since September 2022
Posts: 760
|
Post by vance71975 on May 14, 2023 20:59:28 GMT -5
Your logical question brings to mind the day my husband told me about “cooking” his TV dinner. Directions said something like cook for 30 minutes at 350 degrees. He figured that was 15 minutes at 600 degrees. 😀 Hmmm….😄 ROFLMAO now that is funny. Please dont let him cook anymore!
|
|
|
Post by Pat on May 14, 2023 22:11:53 GMT -5
Ok!👍🏻
|
|
jamesp
Cave Dweller
Member since October 2012
Posts: 36,154
|
Post by jamesp on May 16, 2023 10:03:32 GMT -5
What we discovered was that Lortone and Thumler also sell grit, and half of what they call out on their tumbling recipe seemed to make little or no noticable difference. Something a little more substantial like the big chunks-o-grit jamesp uses or the roughly 1/8 inch garnets Elizabeth uses for spacer/filler to help carry the grit into the nooks and crannys. You can also get the SiC pellets that are recommended for the Lot-O machines, basically action is what you're looking for more than anything. That big SiC around 3/8" in size does not breakdown well Lee. It does start out sharp and cuts quick for a while. Especially if using quadruple doses. After a while it rounds smooth like the rocks and is way less effective at cutting. The fastest cutting I have ever experiences was adding half doses of SiC 30 or 40 or 50 or 60 every two days at higher rpm(60 rpm for 6" barrel for instance). But, you must do a total clean out after a week due to over thick slurry(or earlier for soft rocks). The 30-40-50-60 is sharp and breaks down unlike many of the 3/8 inch SiC particles. That was my findings for step 1. On the contrary, for polish(and finishing steps) less is better. i.e. just enough polish(finish abrasives) to get the polish(finish step) completed. Finishing steps are completely opposite of the cutting step. Two different worlds. More seems merrier when cutting. I was surprised at how small a dose of polish would polish rocks in a vibe(not sure about small polish doses in a rotary). If I quadrupled the dose of polish it took about twice as long to finish the polish step as you will not get a high polish until ALL the polish is broken down. Seems like higher doses of polish take longer to break down... Super high polishes do not happen at 14,000 grit sized polish, only after 14,000 has broken down to 50,000 to 100,000 grit do you get a killer wet polish. These numbers are typical of cab polishes I believe. Note that the (modern)Lot-O instructions say to use tiny doses of polish where as the 40 year old Vibrasonic instructions suggests 8 times more polish per pound of rocks. I use the 1/8 Lot-O dose in my Vibrasonic with great success. Using polish for a slurry thickener is not a path I chose, use Borax or sugar for a slurry thickener, not polish itself. Anyway, that's my 2 cents.
|
|
jamesp
Cave Dweller
Member since October 2012
Posts: 36,154
|
Post by jamesp on May 16, 2023 10:11:28 GMT -5
To test 14,000 polish breakdown, take stones that have been polished in a vibe for 3 days to a dead wet polish. Take those stones and run them for 2 hours in 14,000 polish and the stones will NOT be very polished(polish removed) at 2 hours because the 14,000 has not had time to break down to 50,000 to 100,000. That is how it works with polish.
Tumble polishing(and finish steps)have a great advantage in that the process of tumbling physically breaks down abrasives to many smaller intermediate sized abrasives.
|
|
|
Post by Rockoonz on May 16, 2023 10:33:31 GMT -5
jamesp agreed, the smalls are more to create gaps between the pieces being polished to carry the grit in, it just facilitates the grind. Our coarse recipe has been to begin with about half the coarse grit called out by the lortone/thumler instructions and have the garnet smalls and after a week/10 days/when we remember to check the slurry, and if all is in order add about half the amount of 60/90 and run for roughly a month. At that point most will skip stage 2 because the broken down 60/90 already became 120/220 and move from the 40# drum to 2 15# drums, and the rest will go 1 weekish each stage and a bit may finish with Elizabeths preforms for Guitar picks, earrings and tumble cabs in the UV 10 vibe units. Our 1st AZ batch will start in late July if things go as desired, mostly for the clubs rock show in October.
|
|
|
Post by velodromed on May 16, 2023 20:45:08 GMT -5
To test 14,000 polish breakdown, take stones that have been polished in a vibe for 3 days to a dead wet polish. Take those stones and run them for 2 hours in 14,000 polish and the stones will NOT be very polished(polish removed) at 2 hours because the 14,000 has not had time to break down to 50,000 to 100,000. That is how it works with polish. Tumble polishing(and finish steps)have a great advantage in that the process of tumbling physically breaks down abrasives to many smaller intermediate sized abrasives. In these two posts you explained a lot about the polishing process to me, things I have been wondering about in the back of my mind for quite awhile, but didn’t know how to express. Much appreciated!
|
|
jamesp
Cave Dweller
Member since October 2012
Posts: 36,154
|
Post by jamesp on May 17, 2023 14:58:06 GMT -5
This is an 18 pound load that ran for 30 days at a fast rotation speed. It ran for 4 weeks with a clean out at 2 weeks. Both clean outs were very heavy slurry. It ran with same 3 pounds of large silicon carbide for the whole 4 weeks. Note how the 3/8" to 1/2" silicon carbide chunks have become smooth. Better if they were beaten(crushed a bit) with a hammer to sharpen them for re-use. These were hammer broken rocks, not rounded creek pebbles at 4 weeks:
|
|
|
Post by Mel on May 24, 2023 14:41:04 GMT -5
Instead of more grit, what about something like kaolin clay to help bond the grit to the rocks? I know jamesp uses (used?) that a fair bit. There is also something called Old Miser which claims to help make the grit more effective.
|
|