johnnymac1969
starting to spend too much on rocks
I Like A Rolling Stone
Member since January 2016
Posts: 139
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Post by johnnymac1969 on Mar 12, 2016 0:22:58 GMT -5
After running out of patience with 80 grit (in a Lortone 33B), I recently started using 46/70 for Stage 1. Can I go straight to 120/220 for Stage 2, or should I spend a few days after 46/70 with 80?
Thanks for any and all advice!
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Post by pauls on Mar 12, 2016 5:51:44 GMT -5
Yep, go straight to 120/220. grit breaks down and the longer you leave it the finer your original grit becomes.
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Post by orrum on Mar 12, 2016 9:39:41 GMT -5
I put in 46 70 and then roll it for a month b4 changing grit and sorting rocks. I am thinking it makes my grit go farther and cheaper. I have three 12 pounders, two 6 pounders, a 4 pounder and two double lortone for 3 pound barrels that I put long PVC barrels in so I use a lot of coarse gtit. Then I go to the Loto for my other stages. Welcome to tumbling, I luv it!!!!
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doublet83
starting to spend too much on rocks
Member since March 2016
Posts: 118
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Post by doublet83 on Mar 12, 2016 9:44:10 GMT -5
Doesn't the grit break down pretty quickly and become less effective after a while? Can you really use the same coarse grit for a month (without it slowing down the shaping process a lot) I've been adding new coarse grit every week at 1tbsp per pound of rock.
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Fossilman
Cave Dweller
Member since January 2009
Posts: 20,687
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Post by Fossilman on Mar 12, 2016 9:52:32 GMT -5
No grit doesn't break down quickly,but it does break down in a period of time...I can use the same slurry on a couple different tumbles,after that,than I add grit to the slurry..... You can always tell by what your material looks like in a weeks time,when you pull the barrels for inspections... After awhile,you will know,just buy looking at the slurry,if the grit is enough.....
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jamesp
Cave Dweller
Member since October 2012
Posts: 36,175
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Post by jamesp on Mar 12, 2016 10:08:33 GMT -5
I use SiC 30 and have no problems going to 220 after a week. Maybe a 3 pound barrel will not break down that fast, mine are 6 inch barrels. Bigger grits like 30 and 46 are brittle and break down fast in the first few days. And after a week 120/220 should bridge the 80 gap.
Not a lot of difference between 30 and 46. 120 mixed with 220 is effectively 120, coarsest grit dominates. Look at the ranges, 30 at a low of 595 and 46 at a high of 420. Single sized grits are allowed ranges, and sold accordingly. 46 has a low of 354 and 120 has a high of 125. I would say your 46 is done in a week and ready for 120/220 with no problems.
80 is slow, 46 faster and 30 yet faster in coarse grinding.
30-595 to 707 46-354 to 420 80-177 to 210 120-105 to 125 220-53 to 74
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jamesp
Cave Dweller
Member since October 2012
Posts: 36,175
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Post by jamesp on Mar 12, 2016 10:29:31 GMT -5
Doesn't the grit break down pretty quickly and become less effective after a while? Can you really use the same coarse grit for a month (without it slowing down the shaping process a lot) I've been adding new coarse grit every week at 1tbsp per pound of rock. Yes, add each week. Coarse grit is well worn after a week and loses it's effectiveness. Unless there is too much water or rocks in your barrel. Or you are tumbling very soft rocks that do not break coarse grit down as fast. if you are getting a fair slurry after a week you are guaranteed the grit is breaking down.
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doublet83
starting to spend too much on rocks
Member since March 2016
Posts: 118
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Post by doublet83 on Mar 12, 2016 21:10:15 GMT -5
Yeah, I guess the coarse grit basically becomes a finer grit after a week? So it still has some shaping power but much more limited than new coarse. I generally just dump the new coarse in the existing slurry thinking that maybe there's some fine grit in the slurry that's still doing some work.
I figure with the price of grit being fairly cheap if you buy in bulk, I would just add a full amount of grit each week while reusing existing slurry. If it produces a faster shaping process, you end up saving money on electricity, and wear and tear on your barrels. No idea how much time I'm saving tho by putting in all that grit each week vs being conservative with the grit additions, which some people seem to prefer.
I also ended up using the extra coarse 30 grit, thinking maybe it would be faster, but with limited experience, I'm not sure what difference it makes.
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