piobaire
off to a rocking start
I'm failry new to tumbling and always seem to have questions I cannot answer.
Member since September 2018
Posts: 4
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Post by piobaire on Sept 10, 2018 14:57:19 GMT -5
I have a 3 lb Tumbler and would like to know what is the recommended amount of grit to be used for each stage of the process and if you increae that amount of grit weill that improve the end result. I've come across two aricle relating to the amount of water to add to my tumbler, one says just to add enough to cover the rocks and the other article says to only fill the tumbler to 1 inch below the rocks.
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Post by gmitch067 on Sept 10, 2018 17:34:01 GMT -5
I use the following in my 3 lb barrels... works for me:
80 grit Silicon Carbide graded (60-90 ungraded - nothing coarser) - 3 TBS - (I also use 1-2 TBS kitty litter to help generate a slurry thick enough to keep this heavy grit in suspension - do not use kitty litter in any of the finer grade stages... not necessary). Run for a week then clean out and check for desired shape. If not yet at the desired shape recharge with more 80 grit and go another week... repeat until desired shape is attained... could take a month or two of weekly recharges! Obviously this is the stage that requires the most of any particular grit.
It is common to loose a lot of your tumble's mass as the rocks are ground away and old slurry is removed during clean-outs. When you go to the next tumble you will need to add something to bring the level of rocks back up to within an inch of the top... I use small polished aquarium gravel but you can also use large ceramic media or more of your rough rocks. When you add water (all stages) I add enough to reach just a little over the BOTTOM of the top layer of rocks... not enough to cover them totally.
220 grit Silicon Carbide - 3 TBS - 1-week - Mainly you are trying to remove the scratches caused by the previous 80 grit run(s). DRY a few of the rocks after cleaning them. Take a look at them using a small 10X-20X magnifier lens (loup). If you can see smooth places (220) but still see coarser patches (80), run the rocks through the 220 grit stage again. (note: the magnifier lens is pretty much useless for seeing anything finer than 220 grit scratches). At this point - and forward - you should be extra careful in your clean-outs... avoid contamination by coarser grits!
500 grit Silicon Carbide or 600 grit Aluminum Oxide (AO-600) - 3 TBS - 1 week is usually enough for me. I have both types, but I am using the AO grits more and more... very versatile.
1200 grit Silicon Carbide or Aluminum Oxide 1000 (AO-1000) - 2 TBS - 1 week. This is an added (personal) stage that seems to help as a pre-polish... especially on stones softer than Mohs-5. Once again I find myself using the AO grits more than the Silicon Carbide grits.
AO-14,000 Aluminum Oxide polish - 2 TBS - 1-2 weeks - When you do a clean-out, it is OK to reuse the old polish... don't just dump it out... instead, open the barrel and check out a few dried stones. If the shine is not good, drop them back in and run for another week. If after 3 weeks there is still no shine, set them aside in a Ziploc bag and go to another type of tumble. I have had a few of these... disappointing, but maybe something will come up in the future... Oh well... look forward - not back... (Note the rather healthy jump from AO-1000 to AO-14,000! ... NICE! I have many different types of polishes, but have had such good luck using Aluminum Oxide that I have not used any others for the past 8 months. I like+++)
Burnishing Run: After cleaning out the polish, throw the stones back into the barrel; Fill with water (as before) and add some Dawn soap (or Ivory bar soap - 1 TBS of shavings) - I also use 1 TBS of Borax. Run for 4-7 days. This seems to bring out the shine more, and removes a lot of the polish that gets into cracks and pits. I use a water pic to flush out any left over polish (a little overkill... but works for me)
I hope this helps you.
Glenn
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Post by gmitch067 on Sept 10, 2018 21:38:29 GMT -5
Forgot to address one of your questions piobaire ... sorry. You asked if using more grit would increase the amount of grind... Something I really never considered. Good question. It seems that it would, and in the process cause the slurry to become thicker. When I first started this hobby using a new shiny Lortone 3A, I followed the manufacturer's instructions which called for heavier charges of grit: 60-90 - 4 TBS 220 - 4 TBS Pre polish AO-500 - 6 TBS AO polish - AO-14,000 - 6 TBS That seemed to me to be a bit excessive ($$$ ouch!), and I started cutting back (following many posts on the topic by members of this Forum). I have not noticed any difference to the quality of shine using my present formula. Sooo... my focus was on saving a dollar, not speeding up the time it took to finish a tumble. I would rather save the $$$. Lol! BTW... Welcome to the RTH Forum from Northern California!
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lancemountain
starting to spend too much on rocks
Member since March 2017
Posts: 214
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Post by lancemountain on Sept 11, 2018 1:59:04 GMT -5
kitty litter is interesting! I've never used in the rough stage but searching around it looks like it's a common practice
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piobaire
off to a rocking start
I'm failry new to tumbling and always seem to have questions I cannot answer.
Member since September 2018
Posts: 4
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Post by piobaire on Sept 11, 2018 5:03:12 GMT -5
Thanks for all your help. So pleased to have joined this group. Greetings from Nova Scotia, Canada
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Post by gmitch067 on Sept 11, 2018 8:03:26 GMT -5
kitty litter is interesting! I've never used in the rough stage but searching around it looks like it's a common practice The 60-90 and 80 grits are heavy. A good slurry helps it stay suspended and allows it to coat the surface of the rocks to promote a more efficient grind between the rolling stones. Some rocks like feldspar creates a good slurry on their own, but needs a few days to get there. Other rocks, like Agates, produce a very watery slurry. I usually wait until after the first week of tumbling - during the clean-out - to see what type of a slurry is developing on its own before I start adding the kitty litter. Use of a slurry thickener is NOT mandatory... its use is purely a personal choice. There are a lot of really nice member posts on the topic - both pro and con. A recent example of the debate can be seen in the following post: forum.rocktumblinghobby.com/thread/84570/I live in a city with low access to natural clay... so my source of clay is in cheap kitty litter from the grocery store. If you do decide to try kitty litter as a slurry thickener, try to find a type with the fewest sweet smelling crystals as possible... the more basic clay type the better. I always worry that the chemicals might cause a gas reaction inside the tumbler that could blow the lid off. If you notice the bottom of the barrel popping out like a balloon, or the sides scrapping on the metal housing, it is time to stop the tumble and "burp" the barrel - remove the pressure (use a towel over the lid when you open it... keeps the slurry blow-by contained) - then resume the tumble.
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kengmmhm
off to a rocking start
Member since September 2018
Posts: 2
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Post by kengmmhm on Sept 14, 2018 15:15:19 GMT -5
I have a 3 lb Tumbler and would like to know what is the recommended amount of grit to be used for each stage of the process and if you increae that amount of grit weill that improve the end result. [...] I am new to the hobby as well, and have a similar question about what amounts of grit to use in my 3 lb Thumler A-R1, but it's about units and whose instructions to believe. The recipe in the included manual, as well as other sources, uses ounces as the units for measuring grit. Instrad of or in addition to ounces, some sources give the volume in tablespoons ('T' or 'tbsp' or 'Tbsp'). For larger barrels, some sources recommend a certain number of cups of grit, while others give the quantity in pounds. Whether I measure my grit by volume or weight makes no difference to me -- cups, pounds, and tablespoons (all US measures, I have to assume) need no explanation, but I have a big problem when the only unit given is OUNCE. Nowhere I have read tumbling advice from Anyone who bothers to specify which species of ounce they're talking about: 28 GRAM ounces or 30 MILLILITER ounces? There's no way to tell. They all assume the reader reads writers' minds along with their text. Were it the water in the barrel that's being measured, it wouldn't matter at all, of course, but 60/90 SiC grit weighs ~ 1.5 oz/oz with a volume of ~ 0.66 oz/oz! A 50% measuring error is unacceptable. I know it would be too much to ask for the entire populace of a hobby industry to grow some science and employ clearly defined cgs or MKS units (g & ml or Kg & liters), like the civilized world does. Meanwhile, though, if there is a generally agreed-upon rule of thumb, would someone please recommend effective and minimally wasteful grit quantities for a 3-lb capacity Thumler barrel using unambiguous units? I'd be much obliged.
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Post by gmitch067 on Sept 15, 2018 1:10:18 GMT -5
My use of "TBS" is meant to mean "tablespoon" kengmmhm and piobaire ... sorry for the confusion. Looks like I should be using "Tbsp" I found this dry measurements conversion chart on the web and thought it might help: (Note: The chart shows "DRY" measurements... Not liquid measurements) 9/23/18 Edit to correct a VERY WRONG chart below piobaire : As aDave and kengmmhm point out in the next posts, this chart's conversions to weight is NOT Correct when it comes to grit measurements. I was so focused on Tbsp and oz conversions (to convert Thumler's use of "oz" measurements to "Tbsp") that I did not consider that grit sizes weigh differently. Apologies.I don't think it matters what type of 3 pound tumbler you are using... Lortone 3A or Thumlers AR-1. The amount of different grits seems a bit high to me. I would suggest starting out as the manufacturer's user's guide recommends and make adjustments as you see fit. The amounts I recommended in the previous posts are my own Thumler recommends (in their AR-1 guide) the following: Coarse (probably 80 grit)- 4 oz = 8 Tbsp Fine (probably 220 grit)- 4 oz = 8 Tbsp PrePolish (probably 500 or 600 grit)- 2 oz = 4 Tbsp Polish (Aluminum Oxide 14,000 grit ?)- 2 oz = 4 Tbsp I hope this helps you. Welcome to the RTH Forum from Northern California! Glenn
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Fossilman
Cave Dweller
Member since January 2009
Posts: 20,688
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Post by Fossilman on Sept 15, 2018 9:30:06 GMT -5
I fill my tumblers 3/4 full with rock, than add grit, than add water till its 3/4 full towards the rocks...Cap and roll...
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Post by TheRock on Sept 15, 2018 13:11:19 GMT -5
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Post by aDave on Sept 15, 2018 22:05:29 GMT -5
My use of "TBS" is meant to mean "tablespoon" kengmmhm and piobaire ... sorry for the confusion. Looks like I should be using "Tbsp" I found this dry measurements conversion chart on the web and thought it might help: (Note: The chart shows "DRY" measurements... Not liquid measurements) I don't think it matters what type of 3 pound tumbler you are using... Lortone 3A or Thumlers AR-1. The amount of different grits seems a bit high to me. I would suggest starting out as the manufacturer's user's guide recommends and make adjustments as you see fit. The amounts I recommended in the previous posts are my own Thumler recommends (in their AR-1 guide) the following: Coarse (probably 80 grit)- 4 oz = 8 Tbsp = 113 g. Fine (probably 220 grit)- 4 oz = 8 Tbsp = 113 g. PrePolish (probably 500 or 600 grit)- 2 oz = 4 Tbsp = 57 g. Polish (Aluminum Oxide 14,000 grit ?)- 2 oz = 4 Tbsp = 57 g. I hope this helps you. Welcome to the RTH Forum from Northern California! Glenn I eliminated the chart from the quote, so it didn't take up too much space. When I saw Glenn's posted chart, skepticism immediately crept in. It's not a fault of his by any stretch. I just had a hard time comprehending equivalents with what was showed. From what I understood, this is supposed to be a dry weight measure comparison across the board. That's where I had issues. Ultimately, my concern was a "volume" measurement such as tablespoon (Tbsp) and how it equates to actual weight. I was under the impression that some "dry" materials might be heavier due to their nature, so the conversion (between volume and weight) might not be a good comparison. With this in mind, I did some testing. On one hand, I ended up being surprised a bit, but on the other, my suspicions were confirmed. (I'll get to a punch line down the road. ) I decided to take a level tablespoon of different grits and weigh them out to see what happened. As an outlier, I also chose table salt to see where this would fall in the scheme of things. These are the results: 45/70 Sic .8 oz 24 g 120/220 Sic .8 oz 24 g 500 A/O .8 oz 23 g 14,000 polish .3 oz 8 g Table Salt .7 oz 19 g While, at the end of the day, the "accepted" values in the chart might indicate that everything is pretty close to being equal when it comes to the conversions; the outlier (polish) says this isn't so. What this says for me is that I am not looking for weight when it comes to grit. And that goes to what I have been doing (and alot of other folks here) when it comes to grit amounts. Many of us, in the smaller barrels generally refer to tablespoons when it comes to grit amount. For those using 3 lb barrels in this thread, IMHO, this is the measurement you should probably refer to. Again, think volume vs weight. That said, I was pretty much astounded with what Glenn posted that Thumlers recommended for grit amounts with a 3 lb barrel. In some instances, I think they are exceedingly high. In other steps, I think they're pretty close. Roughly speaking, my grit amounts really don't match up with the manufacturers recommendations. Until I get to polish, I use 1.3 Tbsp of grit per pound of barrel capacity. Some might argue this is a bit high, but it works for me. In my 4 lb barrel, I'm only using 3 tablespoons (Tbsp) of polish for that stage. For you 3 lb users, do the math for the initial steps. (1.3 Tbsp x 3 = 4 roughly.) For polish, you can probably use anywhere from 2-3 tablespoons. So, piobaire and kengmmhm that's the long answer to use tablespoons as your measure of grit for your sized barrels. I wouldn't worry about weight. That's just me.
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kengmmhm
off to a rocking start
Member since September 2018
Posts: 2
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Post by kengmmhm on Sept 16, 2018 15:28:08 GMT -5
My use of "TBS" is meant to mean "tablespoon" kengmmhm and piobaire ... sorry for the confusion. Looks like I should be using "Tbsp" ['TBS' used in place of either the standard 'Tbsp', or the formerly(?) standard 'T' ('t' meaning teaspoon), is not a problem. Indeed, Glenn, I quoted piobaire's post only because my question was similar and I wanted to maintain thread cohesion. Your reply to piobaire's query was quite clear. The confusion, to reiterate, stems not from nonstandard abbreviations, but from the ambiguous use of the two different units that are both named 'ounce'.]I found this dry measurements conversion chart on the web and thought it might help: (Note: The chart shows "DRY" measurements... Not liquid measurements) [I hope I'm not casting personal aspersions here, but this chart is bogus. Specifically, where it converts volume (cols 1-4) to weight ('lb', col 5) and mass ('g', col 6), the chartmaker completely ignores the specific gravity and molecular weight of what is being measured. One Tbsp of soap flakes does not weigh anywhere near 14g, and neither does 1 Tbsp of lead shot -- or milled silicon carbide.
I just reweighed some 60/90 grit, and found that the weight:volume ratio in my previous post, 1.5 oz/oz, was low. My apologies. The mass of 2 Tbsp (1 oz by volume) of grit is not 28 g (1 oz by weight), as the table above claims, but in fact weighs 52 g: 1.9 oz/oz. Ignoring this fact is not a minor error.
IOW, if a writer says to use 1/2 oz of grit / lb of barrel capacity, then since 'lb' means weight, I have to assume that the stated 1:2 ratio of ounces to pounds in the recipe means weight:weight, unless the counterintuitive volume:weight is specified. I would be wrong, though, and into my 3 lb barrel would go 42 g (1.5 oz) of grit, only 1/2 of the intended 78 g (weight of 1.5 fl oz).]
I don't think it matters what type of 3 pound tumbler you are using... Lortone 3A or Thumlers AR-1. The amount of different grits seems a bit high to me. I would suggest starting out as the manufacturer's user's guide recommends and make adjustments as you see fit. The amounts I recommended in the previous posts are my own Thumler recommends (in their AR-1 guide) the following: Coarse (probably 80 grit)- 4 oz = 8 Tbsp = 113 g. Fine (probably 220 grit)- 4 oz = 8 Tbsp = 113 g. PrePolish (probably 500 or 600 grit)- 2 oz = 4 Tbsp = 57 g. Polish (Aluminum Oxide 14,000 grit ?)- 2 oz = 4 Tbsp = 57 g. [Based on what? They don't specify fluid ounces, but you are nonetheless assuming that to the author, 1 oz = 2 Tbsp, and not 28 g (28.35, but w/e). If you're correct, then the amount of SiC grit, at 52g/oz (26g/Tbsp), that you're loading into your barrel is nearly twice what you think it is. In real life, Coarse - 4 oz = 8 Tbsp x 26g/Tbsp = 208 g Fine - 4 oz = 8 Tbsp x 26g/Tbsp = 208 g PrePolish - 2 oz = 4 Tbsp x 26g/Tbsp = 104 g Polish - 2 oz = 4 Tbsp x 26g/Tbsp = 104 g
Since they sell the stuff by the pound and not the pint, that works out really well for them.]I hope this helps you. [ :-\ ]Welcome to the RTH Forum from Northern California! Glenn [I just noted that Thumler's AR-1 guide also recommends the following, for 12 and 15 lb capacity barrels: Coarse - 1 lb Fine - 1 lb Prepolish - 1/2 lb Polish - 1/2 lb
So unless Thumler is saying to measure grit by volume into smaller barrels, and by weight for bigger ones, I think I'll go with the less weighty avoirdupois ounces.
KenG.] Followup (later that day...):
Interpreting Thumler's sloppily written recipe that puts "4 oz" of grit in a 3 lb barrel as M. (mass) -- 4 x 28.35g (1 oz) = 113.4g OR V. (volume) -- 4 x 2Tbsp (1 oz) = 8 Tbsp
and applying the measured density for 60/90 grit of 26g/Tbsp gives the amount of grit to add for each pound of barrel capacity: M. -- 38 g 1 1/2 Tbsp V. -- 69 g 2 2/3 Tbsp
The above "M" value, while many consider to be on the high side, is much more in line with the majority of rules of thumb for the coarse stage, which seems to hover near 1 Tbsp/lb. Accordingly, I just started tumbling ~ a pound of mixed moonstone and apatite in a 3 lb barrel with 4 1/2 Tbsp of 60/90. I'll see in a few days whether I should have doubled it.
Conclusion: The world would be an easier place to live in if those who tenaciously hold onto the clumsy, imprecise, antiquated Imperial system would at least clearly and consistently identify which species of ounce they're referring to, or come up with 2 different names for the 2 different units, or better yet... {remainder of exercise is left for the student}
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Wooferhound
Cave Dweller
Lortone QT66 and 3A
Member since December 2016
Posts: 1,426
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Post by Wooferhound on Sept 16, 2018 17:55:31 GMT -5
More grit is faster grinding Less grit is slower grinding It's your choice . . .
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braat
spending too much on rocks
Member since December 2016
Posts: 350
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Post by braat on Sept 16, 2018 19:02:37 GMT -5
More grit is faster grinding Less grit is slower grinding It's your choice . . . Your comment made me rethink things....I've always thought I was using less grit than I was "supposed" to (2 TBSP weekly in a 12 lb Thumler) but I never really worried about it as my pile of finished stage one rocks is getting bigger because my pre-polish and polish barrels are only 3 lb Thumlers (I skip stage2/220 ). So maybe I could even cut back to 1 TBSP? If I ever thought I needed to increase overall output (no reasons yet) I'd get a Lot O and I'm guessing I'd have to readjust the stage one grit dosage upwards. Anyways right or wrong that's my theory...
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Wooferhound
Cave Dweller
Lortone QT66 and 3A
Member since December 2016
Posts: 1,426
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Post by Wooferhound on Sept 16, 2018 19:44:08 GMT -5
Personally in stage 1, I use 3/4 cup grit in each of my two 6 pound barrels and get great results. But in cleanout, I have a grit recovery system that saves anything bigger than 500 grit.
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braat
spending too much on rocks
Member since December 2016
Posts: 350
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Post by braat on Sept 16, 2018 20:13:02 GMT -5
I forgot to say I also add 2 1/4 cups dried stage one slurry weekly so maybe that's speeding things up some too..
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victor1941
fully equipped rock polisher
Member since November 2011
Posts: 1,992
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Post by victor1941 on Sept 16, 2018 21:34:22 GMT -5
I think the discussion on weight vs volume is very interesting in trying to get the correct ratio for grinding and/or polishing. The machine I use is a Thumler uv-18 vibe for flat preformed or domed cabs. My goal is to remove the scratches and then polish the cabs. I agree with Wooferhound that going light on the grit doesn't serve much of the initial purpose when trying to remove scratches of nonuniform depths. I prefer to have extra grit and run the cycle until the grit is used. Sometimes I need two cycles in coarse grit before moving to the next stage when working with Montana, Brazilian, and other really hard material. I usually skip the coarse grit on softer material or add these cabs toward the end of the cycle or the next cycle. I load the machine by balancing the cab weight-volume and small media until the barrel is full and add the Thumler recommended grit or polish for my machine.
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Wooferhound
Cave Dweller
Lortone QT66 and 3A
Member since December 2016
Posts: 1,426
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Post by Wooferhound on Sept 17, 2018 7:27:15 GMT -5
I've come across two articles relating to the amount of water to add to my tumbler, one says just to add enough to cover the rocks and the other article says to only fill the tumbler to 1 inch below the rocks. Less Water is Faster Grinding More water is Slower Grinding It's your choice . . .
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