sschus87
starting to shine!
Member since November 2015
Posts: 49
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Post by sschus87 on Nov 27, 2015 9:08:33 GMT -5
I am new to this hobby (this is my first post aside from my introduction post) and appreciate all of the answers I have found on here. Your willingness to help newbies in to this great hobby is amazing. That being said, my question is about extra coarse grit. I bought some 60/90 grit to use for my first stage (agates that I am running for 2 weeks in this) but I have seen some people on eBay selling 16 and 30 grit media. Is it worth buying this? Will it cut down the time on the first stage? If I use this do I just skip the 60/90 and move to second stage or does this become a "pre first stage" run?
All help is appreciated!!
Thanks---Steve
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Deleted
Deleted Member
Member since January 1970
Posts: 0
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Post by Deleted on Nov 27, 2015 9:16:13 GMT -5
I've tumbled a few pounds in my day but I'm no expert.i believe those grits will be too course for your barrels.you will suffer premature barrel failure.others will chime in I'm sure Dave
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jamesp
Cave Dweller
Member since October 2012
Posts: 36,159
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Post by jamesp on Nov 27, 2015 9:37:00 GMT -5
I use SiC 30 in PVC barrels. And prefer it over 80 and 60/90 for grinding rate. May wear some barrels faster though. And may break even if it wears the rocks faster. I do not care for 16 grit, it seems to break down in less efficient plates. And 30 was suggested to me by the SiC manufacturer on hard materials like rocks.
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Post by Jugglerguy on Nov 27, 2015 9:48:40 GMT -5
Hi Steve. You can use a more coarse grit, but I wouldn't use 30 grit, and I wouldn't buy it from eBay. I recently switched from 60/90 to 46/70 and I notice a difference. I've heard that it's harder on your barrels, but Drummond Island Rocks has been using it a lot longer and I don't think he's noticed a difference in barrel wear. The Rock Shed sells good grit and so does Kingsley North. I bought 50 lbs of coarse grit from Kingsley North. Don't let the shipping cost scare you. If you ask them, they'll ship it in a large flat rate box ($18, I think). Fifty pounds may seem like a lot, but if you're going to do this much, you'll use it. What most beginners don't understand is that the first stage takes much longer than a week or two. Sometimes it takes months if you have hard, broken stones. Doing the first stage for a set amount of time, like two weeks, isn't a good idea. I prefer to tumble perfect stones, so I keep them in the first stage until every flaw has been removed. Each week, I rinse them off (not into the drain!) and inspect each rock. I remove any rock that has all holes and cracks removed. The rest go back into coarse grind until they're done. I add in more rough rock to make up the volume lost by removing finished rocks and by the decrease in the size of all rocks due to grinding. It's pretty much a perpetual cycle. When I've gathered enough finished rocks, I move those onto the next stage. The hardest part of this hobby when you start is patience. It gets easier as you go. I have two double barrel tumblers running coarse grit all the time. I do a clean out on the larger one every Saturday. The smaller ones get cleaned out on Wednesday. That gives me twice a week that I can see something happening. I do all my finishing in a vibratory tumbler because it's faster and uses much less grit.
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quartz
Cave Dweller
breakin' rocks in the hot sun
Member since February 2010
Posts: 3,341
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Post by quartz on Nov 28, 2015 23:18:03 GMT -5
I run 16 grit very satisfactorily in 12"dia.x12" long PVC barrels. In our 8" set, it doesn't break down near as well, smaller barrels likely worse yet.
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sschus87
starting to shine!
Member since November 2015
Posts: 49
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Post by sschus87 on Nov 29, 2015 0:05:31 GMT -5
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rollingstone
starting to spend too much on rocks
Member since July 2009
Posts: 236
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Post by rollingstone on Nov 29, 2015 1:44:33 GMT -5
Pretty sure blasting grit is just quartz sand, so it would be the same hardness (Moh's hardness 7) as most tumbling materials, so it wouldn't do you any good. Might work for something softer like obsidian or sodalite (Moh's 5). Silicon carbide is I think Moh's 9.1 or 9.3 plus it's very angular and sharp and tends to break into angular and sharp pieces as it breaks down, so it's much superior.
As for your first question, that topic was discussed at length years ago and the consensus seemed to be that 46/70 might hasten things a bit in 6 lb or larger barrels but in smaller barrels it tended not to mix into the slurry very well so was inferior. The even coarser grits you were asking about like 16 and 30 would be even tougher to get mixed into your slurry well. 60/90 has stood the test of time for decades.
-Don
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agatemaggot
Cave Dweller
Member since August 2006
Posts: 2,195
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Post by agatemaggot on Nov 29, 2015 2:03:28 GMT -5
I believe that Black Diamond grit is the glass slag that is skimmed off the top of the molten steel in foundry furnaces. Does a great job in sand blasting operations but not so much in a tumbler !
Harley
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jamesp
Cave Dweller
Member since October 2012
Posts: 36,159
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Post by jamesp on Nov 29, 2015 7:00:38 GMT -5
Use silicon carbide for coarse grind. It is the sharpest and fastest cutting abrasive for the money. By far most of the tumbling time and grit use is spent in the coarse grind shaping the rocks.
Applying the 220-500 and finer grits takes much less work for the tumbler and time since you are just removing pits from the previous grit. And the 220-500 and finer grits only require one charge of grit to get the required results. Where as the coarse grit usually requires 4-12 grit additions and at least several clean outs to remove sludge build up.
Purchasing grit proportions for a moderate scale is 50 pounds of course, and 5 pounds each for finer grits and polish. The cost to tumble is definitely in the coarse grit usage plus electricity used during coarse grind.
The cost for electricity for my 4 barrel tumbler is over $200 per year. Most of that goes to the coarse grind. More than the cost of the grit per year. So pick the most efficient coarse grit for your tumbler.
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jamesp
Cave Dweller
Member since October 2012
Posts: 36,159
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Post by jamesp on Nov 29, 2015 7:40:54 GMT -5
I will add, since the electric bill is $17/month base charge and actual bill averages $45 the cost for the 1/2 HP motor is more like $300/year. Tumbler on a separate meter and is the only device on that electric meter during the winter so I have a good idea of the cost. At that rate, the cost of a new tumbler barrel is almost insignificant over a 3 year period. My 6 inch PVC barrels cost $65 and last at least 3 years.
So I prefer my fast cutting SiC 30 and a bit of clay thrown in to immediately stick the 30 grit to the rocks. I am not one to wait for a slurry to build up to stick the grit to the rocks.
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Fossilman
Cave Dweller
Member since January 2009
Posts: 20,685
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Post by Fossilman on Nov 29, 2015 9:40:49 GMT -5
Stick with your 60/90 grit...Thumbs up
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jamesp
Cave Dweller
Member since October 2012
Posts: 36,159
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Post by jamesp on Nov 29, 2015 10:09:36 GMT -5
Stick with your 60/90 grit...Thumbs up Nobody likes my SiC 30. Feelings hurt and sobbing. LOL What can I say ?
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Post by mohs on Nov 29, 2015 10:45:23 GMT -5
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jamesp
Cave Dweller
Member since October 2012
Posts: 36,159
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Post by jamesp on Nov 29, 2015 10:47:50 GMT -5
mostly Still love my 30 grit Ed.
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jamesp
Cave Dweller
Member since October 2012
Posts: 36,159
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Post by jamesp on Nov 30, 2015 10:43:14 GMT -5
Another thought, a tumbler barrel may wear out after a certain amount of rocks has been tumbled in it. Regardless of the grit used. If it last 3 years running 60 grit or 2 years running 45 grit to tumble 200 pounds of rocks it is folly not to use 45 grit because of a large savings in electricity. And that seems to be my experience. But do not be fooled, the electricity is the most expensive part. More costly than the grit. A simple comparison is running a 100 watt light bulb full-time, it pulls about .9 amps. Probably the same as a small tumbler.
I was surprised 3 years ago in the winter when my greenhouse fans were turned off and the dedicated power meter was $45-base $17= $28/month for 1/2 HP motor.
I removed the 1/2HP motor and replaced it w/a 1/3 HP motor and slowed the 4 barrels down from 55 RPM to all 30 RPM to save power. Meter says it is still $35/month - $17 base = $18 = $216/year. Grit about $150/year. Less since vibe was added.
1/3 HP motor paid for itself in a few months. That was almost 2 years ago.
So don't be surprised if a small tumbler costs more than one would think.
Power company can tell you how much it costs to run a 1 amp motor full-time. Power costs vary.
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mikeinsjc
spending too much on rocks
Member since June 2010
Posts: 329
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Post by mikeinsjc on Dec 3, 2015 12:47:58 GMT -5
Steve, Don't be concerned about using 60/90. I have been using 60/90 for years in Lortone 12 lb barrels and 40 lb barrels and have yet to wear out a barrel. The thin rubber lids on the 12lb Lortone barrels are another matter. They wear out no matter what grit you use.
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bozod
off to a rocking start
Member since September 2018
Posts: 15
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Post by bozod on Apr 11, 2021 20:34:58 GMT -5
Hi Steve. You can use a more coarse grit, but I wouldn't use 30 grit, and I wouldn't buy it from eBay. I recently switched from 60/90 to 46/70 and I notice a difference. I've heard that it's harder on your barrels, but Drummond Island Rocks has been using it a lot longer and I don't think he's noticed a difference in barrel wear. The Rock Shed sells good grit and so does Kingsley North. I bought 50 lbs of coarse grit from Kingsley North. Don't let the shipping cost scare you. If you ask them, they'll ship it in a large flat rate box ($18, I think). Fifty pounds may seem like a lot, but if you're going to do this much, you'll use it. What most beginners don't understand is that the first stage takes much longer than a week or two. Sometimes it takes months if you have hard, broken stones. Doing the first stage for a set amount of time, like two weeks, isn't a good idea. I prefer to tumble perfect stones, so I keep them in the first stage until every flaw has been removed. Each week, I rinse them off (not into the drain!) and inspect each rock. I remove any rock that has all holes and cracks removed. The rest go back into coarse grind until they're done. I add in more rough rock to make up the volume lost by removing finished rocks and by the decrease in the size of all rocks due to grinding. It's pretty much a perpetual cycle. When I've gathered enough finished rocks, I move those onto the next stage. The hardest part of this hobby when you start is patience. It gets easier as you go. I have two double barrel tumblers running coarse grit all the time. I do a clean out on the larger one every Saturday. The smaller ones get cleaned out on Wednesday. That gives me twice a week that I can see something happening. I do all my finishing in a vibratory tumbler because it's faster and uses much less grit. Was this the Ungraded Silicon Carbide 35/70 45 lb package? I've been using the 46/70 From Fundamental Rockhound Products in my 15 lb Tumbler. How much of a difference will it make?
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Post by manofglass on Apr 11, 2021 21:24:01 GMT -5
I was using 46/70 grit to the last 45 pounds I bought Was 35/70 grit it was still in the bottom of the barrel After a week I will probably run it 3 weeks before I check the barrel again
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Post by As I in does tries! on Apr 12, 2021 1:14:12 GMT -5
Stick with your 60/90 grit...Thumbs up Nobody likes my SiC 30. Feelings hurt and sobbing. LOL What can I say ? Greetings for little tumbler barrels between 1.5lb - 5lb 60/90 or Fixed 80 is good enough, however 6lb barrels and up, the bigger the barrel the more grit it eats, with my 12lb barrels basically up to 44lbs of rock eats a pound of grit per load, heaver grit can be used for quicker results, but remember a 80 grit grain can score a rock up to 3mm (0.12 inch) deep, larger grains the deeper the scores it creates. And with Jame's barrels I would'nt want to lift a filled barrel as it probally heavier than mine!
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Post by Jugglerguy on Apr 12, 2021 21:14:06 GMT -5
Hi Steve. You can use a more coarse grit, but I wouldn't use 30 grit, and I wouldn't buy it from eBay. I recently switched from 60/90 to 46/70 and I notice a difference. I've heard that it's harder on your barrels, but Drummond Island Rocks has been using it a lot longer and I don't think he's noticed a difference in barrel wear. The Rock Shed sells good grit and so does Kingsley North. I bought 50 lbs of coarse grit from Kingsley North. Don't let the shipping cost scare you. If you ask them, they'll ship it in a large flat rate box ($18, I think). Fifty pounds may seem like a lot, but if you're going to do this much, you'll use it. What most beginners don't understand is that the first stage takes much longer than a week or two. Sometimes it takes months if you have hard, broken stones. Doing the first stage for a set amount of time, like two weeks, isn't a good idea. I prefer to tumble perfect stones, so I keep them in the first stage until every flaw has been removed. Each week, I rinse them off (not into the drain!) and inspect each rock. I remove any rock that has all holes and cracks removed. The rest go back into coarse grind until they're done. I add in more rough rock to make up the volume lost by removing finished rocks and by the decrease in the size of all rocks due to grinding. It's pretty much a perpetual cycle. When I've gathered enough finished rocks, I move those onto the next stage. The hardest part of this hobby when you start is patience. It gets easier as you go. I have two double barrel tumblers running coarse grit all the time. I do a clean out on the larger one every Saturday. The smaller ones get cleaned out on Wednesday. That gives me twice a week that I can see something happening. I do all my finishing in a vibratory tumbler because it's faster and uses much less grit. Was this the Ungraded Silicon Carbide 35/70 45 lb package? I've been using the 46/70 From Fundamental Rockhound Products in my 15 lb Tumbler. How much of a difference will it make? I used to get 46/70 from Kingsley in fifty pound packages, but at some point they changed the quantity to 45 pounds. I think it probably fits in a flat rate box better.
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