rockhoundmn
noticing nice landscape pebbles
Member since November 2020
Posts: 75
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Post by rockhoundmn on Dec 14, 2020 17:18:23 GMT -5
Hi everyone,
I've been reading for long enough and still don't have answers so I'm hoping you all can help me out with a few newbie questions.
1. How many tablespoons or cups make up 1 pound of 60/90 silicon carbide grit? I can only find info on how many tbsp or cups to use per pound of rock. But I don't know how many lbs of rock I have as I'm yet to buy scales. I have a 5 lb bag of grit and instructions that tell me to use 1 lb per 3/4 full barrel of rock (Thumler's Model B 15 lb tumbler).
2. Is there an average size of rock that should make up the load? Like 1", 1/2", 1/4", 1/8" or something else?
3. Is it necessary to do cleaning and oil maintenance at each recharge/stage of tumbling. I found an example of someone saying they do it for every 10-12 hours of use (same model as mine) and also wonder what everyone else's scheduled maintenance looks like.
4. What kind of spare parts and quantities do you find you need to keep on hand for unexpected maintenance issues?
Thanks in advance!
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Post by Mel on Dec 14, 2020 17:44:02 GMT -5
When I just had one tumbler (way back) a pound of grit would last me anywhere from 1-3 months. One pound of grit (just measured) is a smidge under 1 1/2 cups. Size of rocks.....use a mixture. Don't worry about ratios too much, just don't jam it full of all bigs or all smalls. Oil & maintenance is more "once a month" thing. I find I rarely need to oil my machines, but your mileage may vary. In a year I've done 2 belt tension adjustments, and oiled one machine once, out of 5 tumblers. The only spare parts I keep on hand for my Lortones are belts, and I get those at a supplier labeled as O-rings for about 18 cents each (keep about 20 on hand...only because they come in a pack of 25). No real issues. I do have one machine that hates them (an ancient, very well used 3A) so I spoiled it with 2 "official" Lortone belts this year. Merry Christmas, you horrible machine My Thumler tumbler got no spare parts this year. Hard to find, expensive to ship. If I was more impatient (it's a spare machine), I'd probably pick up a couple lids/gaskets/belts for it just to make the shipping worth the cost. Hopefully this helps.
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lordsorril
freely admits to licking rocks
Member since April 2020
Posts: 766
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Post by lordsorril on Dec 14, 2020 18:07:36 GMT -5
There are a lot of variables when rock tumbling--you can't control them all--don't bother.
1. The 1 cup of grit per barrel load is just an estimate-feel free to adjust it as your results indicate (I usually add more grit if I'm dealing with an entire tumbler of harder materials).
2. There is no average size loadout to a tumbler barrel. Do keep in mind the properties of the stones you are tumbling: Labradorite is Mohs 6 and can break on impact. Quartz is mohs 7, but, can frost. Imperial Topaz is Mohs 8, but, can shatter. I recommend adjusting the loadouts according to what you are working with--certain materials require more smalls/cushioning at some/all points.
3. I only have Lortones: I wipe off the old oil on the bearings and refresh it weekly, but, I also tend to overload them. I have to tighten a belt every few weeks. I have not lost a Lortone belt or motor after 2.5 years of continuous use on multiple tumblers.
4. I keep 1 spare belt for each model of Lortone use. I also keep at least 1 spare lid gasket per every 2 tumblers I use. I've become adept at using radial tire patches and epoxy to effectively patch the barrel lids quite nicely.
Good Luck!
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Post by stephan on Dec 15, 2020 1:58:12 GMT -5
Quick conversion for tbs to weight on silicon carbide: 1Tbs is 15ccs Silicon carbide has a density of 3.22, so 48grams, or 1.7oz per Tbs So 9-10TBS (not heaped) should be right around 1lb of grit (just over 1/2cup)
To ballpark rock weight, agate and jasper have a density of slightly more than 2.5, so one cup of rocks should weigh about 1.25-1.5 pounds. Very “ish,” but a way to ballpark it.
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Post by rmf on Dec 15, 2020 7:52:16 GMT -5
@rouckhoundmn said, "2. Is there an average size of rock that should make up the load? Like 1", 1/2", 1/4", 1/8" or something else?"
Use a mix of sizes for best results. Things less that 1/4" become too small I don't tumble them. when you crack a rock up uses all the sizes in the ratio provided by the hammer. The largest you want finished add 25% larger in rough since you will loose about 25% of the rock you put in in mud.
Bearing lube should be as needed not after each load. tumbler design will dictate
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Wooferhound
Cave Dweller
Lortone QT66 and 3A
Member since December 2016
Posts: 1,423
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Post by Wooferhound on Dec 15, 2020 10:32:19 GMT -5
Don't worry about the weight. You may have a 3 Pound or a 6 Pound tumbler but this is just the size of the machine, it is Not a requirement when you fill it. Fill your barrel up to 2/3 or 3/4 full so it works properly and do not worry about the weight. Scales are not needed for rock tumbling, but they do help out a bit.
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gatorflash1
spending too much on rocks
Active in Delaware Mineralogical Society, Cabchon Grinding and Polishing, 2 Thumlers B's and a UV-18
Member since October 2018
Posts: 375
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Post by gatorflash1 on Dec 16, 2020 10:21:32 GMT -5
Hi RH - Welcome to the party! If you are a normal rock tumbling newbie you will have lots of questions about rock tumbling methodology when you first start. I sure did. But then I found a small book called "Modern Rock Tumbling" that I'm now a big fan of, and recommend. It really gives you the steps to success no matter what type of rocks you like to tumble. All you have to do is follow the basic steps. It is an easy read, lots of good pictures and charts, which is to be expected considering the author is an Engineer. The rock tumbling knowledge in this book will save you a lot of time and relieve a lot of frustration. I refer to my copy frequently. It is a good reference book. Here is a link to it and the contents. rocktumbler.com/book.shtmlI look forward to seeing pics of your first batch of tumbles. Good luck!
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electrocutus
spending too much on rocks
Member since October 2020
Posts: 331
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Post by electrocutus on Dec 16, 2020 10:34:32 GMT -5
Hi RH - Welcome to the party! If you are a normal rock tumbling newbie you will have lots of questions about rock tumbling methodology when you first start. I sure did. But then I found a small book called "Modern Rock Tumbling" that I'm now a big fan of, and recommend. It really gives you the steps to success no matter what type of rocks you like to tumble. All you have to do is follow the basic steps. It is an easy read, lots of good pictures and charts, which is to be expected considering the author is an Engineer. The rock tumbling knowledge in this book will save you a lot of time and relieve a lot of frustration. I refer to my copy frequently. It is a good reference book. Here is a link to it and the contents. rocktumbler.com/book.shtmlI look forward to seeing pics of your first batch of tumbles. Good luck! I don't want to hijack the discussion, but does anyone have any leads on how to get the "Modern Rock Tumbling" book in Canada not too expensively? rocktumbler.com does not ship to Canada, and the cheapest used copy I found on Amazon Canada is asking $80. Amazon US will not ship that book to Canada. Does anyone know how I could reach the author to ask about purchasing an e-book version maybe? Thanks!
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Post by Mel on Dec 16, 2020 13:17:01 GMT -5
Hi RH - Welcome to the party! If you are a normal rock tumbling newbie you will have lots of questions about rock tumbling methodology when you first start. I sure did. But then I found a small book called "Modern Rock Tumbling" that I'm now a big fan of, and recommend. It really gives you the steps to success no matter what type of rocks you like to tumble. All you have to do is follow the basic steps. It is an easy read, lots of good pictures and charts, which is to be expected considering the author is an Engineer. The rock tumbling knowledge in this book will save you a lot of time and relieve a lot of frustration. I refer to my copy frequently. It is a good reference book. Here is a link to it and the contents. rocktumbler.com/book.shtmlI look forward to seeing pics of your first batch of tumbles. Good luck! I don't want to hijack the discussion, but does anyone have any leads on how to get the "Modern Rock Tumbling" book in Canada not too expensively? rocktumbler.com does not ship to Canada, and the cheapest used copy I found on Amazon Canada is asking $80. Amazon US will not ship that book to Canada. Does anyone know how I could reach the author to ask about purchasing an e-book version maybe? Thanks! I tried to find his site online when I was looking for a copy, and came up empty. I would say see if your local independent bookstore (or if you have none, McNally or Indigo) can order it in.
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Post by miket on Dec 16, 2020 14:26:22 GMT -5
Hi RH - Welcome to the party! If you are a normal rock tumbling newbie you will have lots of questions about rock tumbling methodology when you first start. I sure did. But then I found a small book called "Modern Rock Tumbling" that I'm now a big fan of, and recommend. It really gives you the steps to success no matter what type of rocks you like to tumble. All you have to do is follow the basic steps. It is an easy read, lots of good pictures and charts, which is to be expected considering the author is an Engineer. The rock tumbling knowledge in this book will save you a lot of time and relieve a lot of frustration. I refer to my copy frequently. It is a good reference book. Here is a link to it and the contents. rocktumbler.com/book.shtmlI look forward to seeing pics of your first batch of tumbles. Good luck! I don't want to hijack the discussion, but does anyone have any leads on how to get the "Modern Rock Tumbling" book in Canada not too expensively? rocktumbler.com does not ship to Canada, and the cheapest used copy I found on Amazon Canada is asking $80. Amazon US will not ship that book to Canada. Does anyone know how I could reach the author to ask about purchasing an e-book version maybe? Thanks! abebooks.com has several copies, free shipping within the U.S.- I don't know what it would cost to ship to Canada. The cheapest copy (used) is $38.95.
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gatorflash1
spending too much on rocks
Active in Delaware Mineralogical Society, Cabchon Grinding and Polishing, 2 Thumlers B's and a UV-18
Member since October 2018
Posts: 375
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Post by gatorflash1 on Dec 16, 2020 14:37:34 GMT -5
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Post by Mel on Dec 16, 2020 15:00:29 GMT -5
I don't want to hijack the discussion, but does anyone have any leads on how to get the "Modern Rock Tumbling" book in Canada not too expensively? rocktumbler.com does not ship to Canada, and the cheapest used copy I found on Amazon Canada is asking $80. Amazon US will not ship that book to Canada. Does anyone know how I could reach the author to ask about purchasing an e-book version maybe? Thanks! abebooks.com has several copies, free shipping within the U.S.- I don't know what it would cost to ship to Canada. The cheapest copy (used) is $38.95.
Media mail is usually pretty cheap but Abebooks wants $25 US for shipping + then you're most likely looking at $10-20 CDN in customs. Looks like it's cheaper to just order it via Amazon; free shipping helps soften the blow :\
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Post by amygdule on Dec 16, 2020 15:00:34 GMT -5
Hi everyone, I've been reading for long enough and still don't have answers so I'm hoping you all can help me out with a few newbie questions. 1. How many tablespoons or cups make up 1 pound of 60/90 silicon carbide grit? I can only find info on how many tbsp or cups to use per pound of rock. But I don't know how many lbs of rock I have as I'm yet to buy scales. I have a 5 lb bag of grit and instructions that tell me to use 1 lb per 3/4 full barrel of rock (Thumler's Model B 15 lb tumbler). Thanks in advance! 1 pound of 60 grit is a little over 1 cup in volume. About 250cc I just use a paper coffee cup or a plastic 9 oz cup for a scoop in my 12-15 lb barrels.
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electrocutus
spending too much on rocks
Member since October 2020
Posts: 331
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Post by electrocutus on Dec 16, 2020 16:57:06 GMT -5
Thanks for the link. I bought the ebook - no shipping, no wait!!
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Post by Mel on Dec 16, 2020 17:14:15 GMT -5
Thanks for the link. I bought the ebook - no shipping, no wait!! HOW DID I NOT SEE THIS....shame on me! Bought! Thanks for pointing it out gatorflash1 and electrocutus .
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rockhoundmn
noticing nice landscape pebbles
Member since November 2020
Posts: 75
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Post by rockhoundmn on Dec 16, 2020 23:06:07 GMT -5
Thanks again for the help everyone!
Just bought myself the e book for Christmas.
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rockhoundmn
noticing nice landscape pebbles
Member since November 2020
Posts: 75
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Post by rockhoundmn on Dec 17, 2020 7:41:04 GMT -5
It's so easy to read I have already finished the rotary tumbling section of the book and learned so much! I've seen it mentioned often and definitely am glad I bought it. I expect I'll be referring to it often.
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gatorflash1
spending too much on rocks
Active in Delaware Mineralogical Society, Cabchon Grinding and Polishing, 2 Thumlers B's and a UV-18
Member since October 2018
Posts: 375
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Post by gatorflash1 on Dec 17, 2020 16:14:21 GMT -5
Hi All!
Glad you found the book. To answer the original question: a tablespoon of grit is about 1oz +/-, a tablespoon of polish is 1/2 oz. The amount used per pound of rock varies depending on they type of rocks and tumbler. A rotary usually takes more than a vibratory tumbler because it isn't quite as effective. I just wrapped up an 18lb batch in my vib using Cerium Oxide.
Happy Holidays!
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Post by Bob on Jan 19, 2021 10:58:01 GMT -5
This is sort of a tangent but also related. I converted tablespoons to cups years ago, and throw 1/2 cup of grit or polish in the 6lb barrel, 1 cup in the 12lb barrel, 2 in the 20lb, and 4 in the 4 40lb. It seems close enough and works well.
What would happen if we went overboard or underboard? Has anyone ever tried it to see what happens? I'm going to take a guess, but this is only a guess.
If batches usually are just right after a week (a timing which I kind of like also) wouldn't using too little grit merely mean the batch would get done sooner because the grit would be worn out sooner? Or would the grit still "last" a week just a lot less grinding would happened?
Is the reverse true? What if I threw in 2 cups (twice normal) of coarse grind grit in a 12lb barrel? Would it grind twice as much rock off in a week so would not be a waste of money? Or would the grit last longer than a week?
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rockhoundmn
noticing nice landscape pebbles
Member since November 2020
Posts: 75
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Post by rockhoundmn on Jan 19, 2021 23:04:51 GMT -5
Love the ideas and questions floating around here. If I could figure out how to reply to all of them on my phone using quote feature, I would. Please just know I'm reading and absorbing every reply and am very grateful!
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