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Post by Jugglerguy on Jan 10, 2015 11:04:06 GMT -5
I've seen that picture a few times, but I'm sure not tired of seeing it! I have to say that I don't notice much difference between my rocks before and after polishing because they come out pretty darn shiny after 2-3 days in 1000 grit and borax.
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tkvancil
fully equipped rock polisher
Member since September 2011
Posts: 1,546
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Post by tkvancil on Jan 10, 2015 11:19:26 GMT -5
I'm kind of in the same place Jugglerguy is. Meaning that my first kit came with 80 sic, 240 sic and 600 sic which worked well in the rotary so that is what I've always used. I added AO 1000 to my rotary efforts when doing my first batch of Labradorite. Rock Shed and RTH members recommended it so I went with the voice of experience. I can say that in the rotary the 1000 did give an almost shine I never saw with the sic 600 as a prepolish. The 600 did a fine job for agates and hard stuff, always got a good shine with Rock Shed AO polish after. The obsidian batch I did last was telling. Followed Krystee's recipe with the exception of sic 600 instead of AO 500, it was what I had. The 600 made a very smooth surface but did not make a shine after 96 hours. I added the next step with AO 1000 which did give a shine. It may well be that the sharp edges of sic vs. the more rounded break down of AO is the reason. I have entered this years world tumbling competition. I will purchase some AO 500 based on Drummond Island Rocks posts showing his excellent shine coming out of 500. Don't have a ton of vibe experience. Currently running my fourth batch. It is a mix of agate, jasper, quartz, chert and unakite. Did 24 hours in 240, then 24 hours in 600, both sic. No shine yet but none expected. Everything is currently running in AO 1000 which after 24 hours has began to give a surface that reflects light. I'll let this go at least 72 hours, letting the surface quality determine if more time is worthy. I did find this interesting ... I did a burnish after the 600 using borax. Two 2 hour cycles to get the rocks as clean as I wanted them to be. There was a definite improvement. Rocks that reflected no light had a matte type shine which could be seen if oriented to the light source correctly. As mentioned earlier in this thread borax could be a "prepolish" itself.
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Post by Jugglerguy on Jan 10, 2015 12:32:44 GMT -5
Ken, in my vibe, I usually let the rocks run for 2-3 days in each stage. I know that three days is probably overkill, but then I think about Krystee's recipe that goes for five days. It may be that the softer rock takes longer to break down the grit as James has theorized. Anyhow, after two to three days in 500 AO, my rocks are usually quite shiny.
I'm still wondering if there is a difference in a rotary tumbler. RollingStone's rocks are just so shiny and he uses SC.
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jamesp
Cave Dweller
Member since October 2012
Posts: 36,169
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Post by jamesp on Jan 10, 2015 14:17:57 GMT -5
Good to hear those w/Lotto-O vibes converse. It is an apples to apples comparison to some degree. Machinery varies from one to the next.
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tkvancil
fully equipped rock polisher
Member since September 2011
Posts: 1,546
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Post by tkvancil on Jan 10, 2015 18:33:20 GMT -5
I actually have a thumlers and am still in the learning process. Each batch is getting better and I hope this current one is a step up.
Rob, I think I agree with James on the point of softer rocks taking longer to break down grit. Seems logical. I remember doing feldspars in the rotary. After 10 days I could see a little bit of 600 not broken down. Never saw that when rolling agate for 10 days.
Pure speculation but perhaps sic would work best in the rotary. It's a less aggressive process than vibratory.
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jamesp
Cave Dweller
Member since October 2012
Posts: 36,169
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Post by jamesp on Jan 10, 2015 19:56:32 GMT -5
The only grinding operation that simulates tumbling that I could find is lapping. In many cases lapping abrasive is used till it breaks down, and the part being lapped ends up with a finer finish as the abrasive breaks down.
If tumbling gypsum or talc with AO, I doubt AO would ever break down.
On a series of cab wheels there is no breakdown, you just use a lot of steps, and diamond abrasive that hardly ever breaks down.
I wonder if finishing obsidian to a polish is any different than agate on a set of cab wheels.
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Post by broseph82 on Jan 11, 2015 2:37:04 GMT -5
Keep these covos going! I can only improve by reading such
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jamesp
Cave Dweller
Member since October 2012
Posts: 36,169
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Post by jamesp on Jan 11, 2015 7:41:37 GMT -5
Keep these covos going! I can only improve by reading such Don't expect any over night miracles Jimi. Takes time to try new stuff in the tumbling biz.
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Post by snowmom on Jan 11, 2015 8:35:57 GMT -5
love learning through what information others can offer... great thread!
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jamesp
Cave Dweller
Member since October 2012
Posts: 36,169
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Post by jamesp on Jan 11, 2015 8:53:04 GMT -5
love learning through what information others can offer... great thread! Nothing but a bunch of lowly rock grinders snowmom.
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Post by snowmom on Jan 11, 2015 9:03:57 GMT -5
my kind of people!
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tkvancil
fully equipped rock polisher
Member since September 2011
Posts: 1,546
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Post by tkvancil on Jan 11, 2015 10:05:55 GMT -5
love learning through what information others can offer... great thread! Nothing but a bunch of lowly rock grinders snowmom. Don't let James fool you snowmom. We're all rocket scientists.
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Post by broseph82 on Jan 11, 2015 11:08:51 GMT -5
Keep these covos going! I can only improve by reading such Don't expect any over night miracles Jimi. Takes time to try new stuff in the tumbling biz. Oh I'm not expecting miracles, but if you do all the work a head of time for me then I don't have to waste time, grit, or rocks to get my achieved results?
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tkvancil
fully equipped rock polisher
Member since September 2011
Posts: 1,546
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Post by tkvancil on Jan 13, 2015 12:40:02 GMT -5
Just got a new lortone tumbler. Their manual says 60/90 SC, 120/220 SC, AO pre-polish (grit size not specified) and then AO polish.
SIC is for grinding and AO is for shining?
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Post by captbob on Jan 13, 2015 12:44:29 GMT -5
Kinda... The coarser AO can be used in the grinding stages, although AO might be considered a less aggressive grind than SiC in the same grit - like 220 or 500.
I sure would use a step between the 120/220 and the pre-polish tho.
What type of tumbler did ya get!
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Post by Jugglerguy on Jan 13, 2015 13:30:14 GMT -5
Ken, congrats on the new tumbler. I have two Lortones and I like them.
I like your explanation of SC for grinding and AO for polishing. Not that I disagree with Bob, but I think generally that is a good way to sum it up.
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nwbeacher
off to a rocking start
Member since August 2018
Posts: 2
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Post by nwbeacher on Aug 14, 2018 0:54:21 GMT -5
This is a wonderful thread, thanks for all the data.
My wife and I are excitedly getting into rock hounding with our kids picking up pretty and sparkly pebbles off the beaches here in the San Juan Island area. We got a MiniSonic vibe from Craig's list with a 5 step set of grits. They only read, "60/90," "120/220," "400," "Prepolish" and "Polish."
I called the guy that sold it out of a gem shop in Idaho. A super nice guy who might be the same age as the agates we're plucking off the beach. Anyway, he was able to tell me the polish is a "CPP Aluminum" and the pre-polish is "Crematious Earth" Which I can only assume is a tripoli or diatome product as you seem to be expressing in the posts above. The gentleman said it was cheap and seemed to have properties to grind at about 600 grit. So far we like it.
I've been pulling my hair out wondering why I can't find any info on this stuff on the internet and am so glad to be getting this figured out. It seems there are a lot of synonyms that make things tricky, or perhaps some of these names are brand names. I may be too old myself to be trying to learn new tricks. It's almost as bad as the latest update to my phone...
Cheers!
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Post by grumpybill on Aug 14, 2018 6:59:40 GMT -5
Welcome to the forum, nwbeacher . Lots of knowledgeable helpful people here, and with your sense of humor you'll fit right in. To add my (limited) experience to the discussion: When the local rock shop was doing away with their tumbling grits, I bought the remaining stock at a great price. It included SiC in 400 and 600 grit. I've used both with hard stones in a Lot-O vibe after the 220 stage and the only difference I've noticed between those and 500 AO is that the batches with SiC need a bit more attention to keep the slurry wet. This indicates to me that SiC cuts away more rock than AO. I'm still developing my obsidian recipe, but have already decided that SiC is inappropriate after the 220 stage. For man-made glass I find that a shorter run time (no longer than 36 hrs. per stage) using AO 500/1000/polish works best. I get too many micro fractures if I run longer.
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