mikeinsjc
spending too much on rocks
Member since June 2010
Posts: 329
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Post by mikeinsjc on Jan 23, 2011 16:29:20 GMT -5
I attend Quartzsite/Tucson every year. And each year I see tons of beautifully polished stones for sale, in large bins that have been fork-lifted and jostled and kicked and manhandled around all the way from Brazil or kingdom come or wherever, and the rocks still look great. Soft stone. Hard stone. Fossils. You name, it shines like my bald head at an Angels game. Like snowflake obsidian that looks better than anything I have ever managed to produce with my carefully graded grit and closely watched tumble times, etc. etc. How is it that poverty-wage peasants in grungy working conditions using beat up cement mixers or 10-ton tumblers full of beach sand or road gravel or industrial waste manage to produce quality tumbled stones, the quality of which continually, from the perpetual questions asked here, seems to elude rock tumbling people here? And me. Maybe we should pitch in and fund a fact-finding trip for someone to go to Brazil, and have someone simply find out HOW IN THE HECK TO TUMBLE ROCKS? These folks have this procedure down, guys. I doubt that the production facilities are filled with retired old codgers with loupes and I-Know-the-secrets-to-tumbling-and-you-don't smirks on their faces, checking each rock for scratches, or running the rough cycle for eleven weeks, recharging every week.
I have the suspicion the whole process is stupid simple. They probably have the Girls from Ipanema cart in pails full of beach sand, throw it into the back of a cement truck sitting up on concrete blocks, and never change it at all. They run it until the rocks shine, and ship 'em.
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Post by Toad on Jan 23, 2011 16:35:30 GMT -5
That's a theory. But don't think it has worked for anyone on this site. Maybe the girls from Ipanema can be bribed to reveal their secrets...
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snuffy
Cave Dweller
Member since May 2009
Posts: 4,319
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Post by snuffy on Jan 23, 2011 16:43:32 GMT -5
An old rock shop owner told me that in Brazil they just use coarse grit, as it breaks down,they save it,dry it,and then use it again in the other stages.Now I'm repeating what I was told by him. I suppose it will finally break down to polish size.
snuffy
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Post by susand24224 on Jan 23, 2011 16:55:00 GMT -5
It is obvious that I need to attend Quartzite so that I can be even more disgruntled with my tumbles.
Thanks for the laugh!
Susan
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marinedad
freely admits to licking rocks
Member since December 2010
Posts: 813
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Post by marinedad on Jan 24, 2011 8:27:09 GMT -5
i feel your pain, after a year of tumbling, non stop, multi tumblers going, i finally had a batch that turned out good from start to finish. i just hope i learned enough from others here i can continue turning out nice batches.
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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 Jan 24, 2011 11:07:10 GMT -5
A friend starts w/generally 80 grit SC, lets it run for about 2 months, then puts in some auto rubbing compound and/ or Spic-&-Span [quantities ukn., secret] that he picks up at garage sales. He runs this for a couple weeks. The rocks don't smell too good, but he does get a good polish.
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Sabre52
Cave Dweller
Me and my gal, Rosie
Member since August 2005
Posts: 20,463
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Post by Sabre52 on Jan 24, 2011 17:45:26 GMT -5
*LOL* It's not rocket science but it is a hobby for the pathologically patient and obsessive individual. Just a few simple rules 1. Tumble stuff of similar hardness, remembering that soft and porous stuff usually won't polish well at all or is extremely difficult. 2. Patience: Run stuff in coarse grind a very long time for good rounded smooth shapes 3. Don't cross contaminate your lots. If you don't have a dedicated barrel for at least rough and fine grind in one and prepolish and polish in the other, it's very difficult to clean the grit from your barrel and avoid contaminating your later stages 4. Always run a good mix of sizes. 5. Use plastic pellets in the last three stages and 6. Fairly long pre polish and polish runs ( at least four or five days in the vibe and as much as two weeks in a rotary for me at least)....Mel
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Post by Jack, lapidaryrough on Jan 24, 2011 18:18:10 GMT -5
And i thought i was doing it wrong, 50 Lbs, rock, 3 Lbs. 60/90 + 3 weeks = 1200 grit in muddy rock soup.
Doing the same with a load of Fire agates as i type.
Snuffy, The Brazilian are wright, Why waste time. Though the light weight tumblers it won`t work in, 12 Lb`er or less. using the 60/90 - or 80 grit.
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rockhound97058
freely admits to licking rocks
Thundereggs - Oregons Official State Rock!
Member since January 2006
Posts: 760
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Post by rockhound97058 on Jan 24, 2011 18:54:59 GMT -5
I myself never used anything more than simple terms. I do see folks taking way too much time and effort to tumlble, but then again they use the finished stones for jewelry projects. When I tumbled I used a 12# tumbler - Charge it with 60/90 and let it go 3 weeks 24/7. I never opened it, never re-charged it, never used the dang pain in the arse pellets, etc... After that I washed everything very well. Used the same barrel and charged it with 220 - ran it 7 days, dumped - washed and charged with polish and ran another 7 days. The only major thing I did was keep the material the same. Agate with Agate etc, and I used to tumble alot of slabs, and cut pieces, and avoided the pitted rough stones. I never had any problems, and my stones were nice with a high gloss polish. Then I dump them in rubbermaid tubs and give them away at my booth at shows for the kids as pocket rocks.
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mikeinsjc
spending too much on rocks
Member since June 2010
Posts: 329
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Post by mikeinsjc on Jan 24, 2011 20:04:35 GMT -5
I'll bet lapidaryrough (sorry, don't know your name!) is onto something. The smaller the tumbler, the less action the rock sees, the more you have to nurse it along, and your run times for each cycle take forever. In one rotation of the Brazilian mondo tumblers, I bet the rock probably travels three feet or more, wheres in any tumbler most hobby guys can usually afford the rock probably moves, what, three inches in a rotation? I would bet we would be quite surprised how short their total tumble times are and how fewer grit types they use. I'll bet they use one tumbler and one grit for the entire cycle, and a seperate unit for polish. Bet they never clean any of them.
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mikeinsjc
spending too much on rocks
Member since June 2010
Posts: 329
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Post by mikeinsjc on Jan 24, 2011 20:29:08 GMT -5
Also of interest is that the bins full of rocks are pretty much the same size. I suspect the rough is crushed and screened to a uniform size prior to tumbling. If you think about the physics of tumbling, I would assume the use of a variety of sizes in the load as well as using pellets are meant to better carry the grit to all parts of the load- in effect this is a compensation for the insufficient motion of the stones in small tumblers.
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drjo
fully equipped rock polisher
Honduran Opal & DIY Nut
Member since May 2008
Posts: 1,581
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Post by drjo on Jan 24, 2011 20:50:09 GMT -5
Anyone notice we have no central/south American members?! huh.
196 countries in the world and we've got .... 4?
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Sabre52
Cave Dweller
Me and my gal, Rosie
Member since August 2005
Posts: 20,463
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Post by Sabre52 on Jan 24, 2011 21:09:57 GMT -5
I used to use the 60/90 and let' er roll a long time method too, but I found, without recharging the coarse grind, that the hard rocks, like agate, didn't change shape much after the first week or so. I guess it's a matter of what you want for a finished product. I don't mind preserving shapes on things like pet wood but mostly I prefer smoothly rounded shapes which I've never gotten without several weeks and several recharges of 60/90.....Mel
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Post by MyNewHobby on Jan 24, 2011 22:05:18 GMT -5
RockHound97058 .... Sing it boy!!! I agree 100% ... I have learned this only by trial and error (and lots of my famous DUH questions).
Load the sucker up, let er rip, and when you remember that you have batches running (not a good idea with obsidian), check it, load er back up, and let er rip!
The size of the barrel does not count in my opinion! If you load it up with the proper proportions and similar MOHS and then let er rip .... TADA!!!! a BEEEEEEEAutiful Batch!!!!
I have the patience of a five-year old and thank God I have many parents here to take care of me when I develop a really bad case of the stupids!!!!
Once again ... let's say it together .... Load it up and let er rip!!!!
The most important thing about rock tumbling is ... are you having fun? If not, then step back and learn more about the rocks. Then you WILL start having fun and you will start seeing results.
Once again .... load er up and let er rip!
TADA!
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Post by Jack, lapidaryrough on Jan 24, 2011 23:39:28 GMT -5
picasaweb.google.com/lapidaryrough/MyDocuments?authkey=Gv1sRgCLaE_Kq5kYKVQg#5565983332756028658A Close up of my home made tumbler, with a Ohio gear reduction box, geared to 16.5 RPM. This the one i use 60/90 in, Now i do a clean out to sort material that needs to go to next step. I have been running 35 Lbs, fire agate pre-windowed and cut for tumbling. though i dump in holley blue, garnets 4-6mm in size, and about 10 lbs. bruneau. in tumbler is about 50 lbs. of material. all size`s fro 1/4 minus to 2 inch material. And i wash the mud and recover the grit to, i use it for the next 60/90 load with fresh grit. The Vibra tumblers i use for the 220 grit and the polish phase`s. Now size does matter i don`t use small hobby equipment, most of my lapidary shop was built by myself our a bought use equipment from friends that. The taller the drum on a tumbler, better the action and the tear drop of the materials fall from th top to the slope of fall. And the RPM, Most important to run the RPM to the edge of the high speed. Just at the point that your not tossing the material forward. Jack Cole - lapidaryrough Oregon
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Post by Jack ( Yorkshire) on Jan 25, 2011 3:13:03 GMT -5
Hi Mynewhobby, Sorry to disagree but I have proved this in my own tumbling experiance, Mynewhobby you said quote [glow=red,2,300] The size of the barrel does not count in my opinion! If you load it up with the proper proportions and similar MOHS and then let er rip .... TADA!!!! a BEEEEEEEAutiful Batch!!!![/glow] I Would say from experiance and observation that it does as from what is happening inside the barrel 1 - In a small barrel (1 1/2 lb) the weight of the stones in the mixture is very little compared to even say a 4 1/2 lb barrel 2 - I found the grinding a lot better in the bigger barrel (4 1/2 lb) due to rock weight (a simple experiment trying to grind a rock , when grinding use varing presures you will soon find more presure = more rock removed ) This is what Jack Cole above says " Taller the drum ECT - - - - - Here is a link to a BIG old Australian tumbler (Lightening Ridge) img.photobucket.com/albums/v357/john-edward/2010/DSCF0233.jpgHave a good day Jack Yorkshire uk
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mikeinsjc
spending too much on rocks
Member since June 2010
Posts: 329
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Post by mikeinsjc on Jan 25, 2011 11:22:09 GMT -5
Jack, I totally agree on drum size. This is why so many hobby tumblers end up in thrift stores. The bottom line in polishing effectivness has to be total motion of the stones. This is why vibratory tumblers work quicker than rotary. The motion of the rock is different- oscilliatory in a vibrating machine, whereas the motion of a rock in a rotary resembles the graph of a ramp function-rising and dropping, rising and dropping. The net total movement of the rock, for machines of approximately the same size, is greater in a vibratory machine.
So, that said it seems the most effective tumbler you can use is one in which the drum diameter, not necessarily overall volume, is greatest. The greater diameter will impart more motion to the rock, reducing the need for measures that are meant to enhance delivery of the media to all parts of the load. These measures are required not to enhance the final shine as much as making up for the shortfalls inherent in tumblers imparting minimum motion to the rocks by their design. Buy big!
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Post by Jack, lapidaryrough on Jan 25, 2011 11:30:25 GMT -5
Been told for decades SIZE Do`s matter.
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snuffy
Cave Dweller
Member since May 2009
Posts: 4,319
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Post by snuffy on Jan 25, 2011 13:07:09 GMT -5
I know from my own experience that the larger barrels work so much better. I've got from the 3a,acouple ce's, couple of 45c's,2 Lortone 12 lb ers.There is a huge difference between them, the 12lber's get the rock done so much quicker. On mine, I usually recharge coarse weekly up to 3 times with coarse.On the last recharge, I let it go 2 weeks,the grit breaks down.Then I move to 3 days 1000 in my Lot-o,then 3 days polish.
snuffy
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Post by MyNewHobby on Jan 25, 2011 13:55:06 GMT -5
Good Morning! Thanks for all the information. There are a number of things here that I did not know. I do hope my batch is not a complete disaster. As Always!!
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