hbonly
off to a rocking start
Member since December 2012
Posts: 7
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Post by hbonly on Dec 10, 2012 18:47:11 GMT -5
Hi. Some "basic" questions. I bought a used Ultra Vibe UV-18 for tumbling my Lake Superior agates. My first batch, I did not go long enough on the first phase, the 120-220 grit. I only went 24 hours. This left my agates a little more pitted than I would have liked. Question 1; can I, or should I, redo these rocks from square one? I did go all the way through burnish stage and they look ok BUT, where the pits are, there is gray (I assume it is grit) matter in the pits. I don't mind the pits but how do I clean them so they grit is gone? Should I redo them? Can I?
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herchenx
Cave Dweller
Member since January 2012
Posts: 3,360
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Post by herchenx on Dec 10, 2012 18:55:45 GMT -5
welcome hbonly
I use a UV10 and it works great, but I always pre-round the stones either in a rotary tumbler or on a diamond wheel. In any case, there are no pits in my stones before I move them to 120/220 in the vibe. Any pits or cracks carry grit.
There are a couple important things with tumbling in general - one of the cardinal rules is make sure that no grit carries from one stage to another. To ensure this, pit-free and crack-free stones are very important. If you don't want to wait for a rotary to do the job, a wheel or some sort of grinding tool are required.
I have deliberately left pits in some stones because I want the look, but in those cases I hand-wash each stone and burnish the batch to make sure there is no grit.
I also use a separate barrel for the final polish stage - again to ensure no grit is carried into the polish stage.
You can of course always restart as long as you don't mind the wait.
I have superior agates that I have been tumbling all year on and off. They take weeks or months in a very full load in the rotary tumbler to get them smooth without cracking them worse. Post some pics of what you have if you can.
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Minnesota Daniel
freely admits to licking rocks
A COUPLE LAKERS
Member since August 2011
Posts: 891
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Post by Minnesota Daniel on Dec 10, 2012 19:23:04 GMT -5
First, welcome. Second, that's a lot of Lakers! Third, follow Biker Randy's instructions for the vibe tumbler -- 4th thread from the top.
You get rid of the pits with 60/90 grit in a rotary tumbler, or as John suggests, with a diamond wheel. It takes a long time in the 60/90 to get the pits of a Laker smoothed out. Don't move the load to the vibe until it's ready for the 120/220. In this case, the pits need to be shallow enough for you to accept.
Sometimes I use a Dremel tool with a diamond burr to round out the bottoms of pits so I can at least clean the grit and polish out of the them, if they're too deep to grind off completely. Some Lakers have so many deep pits that they aren't good candidates for tumbling. I set those aside until I can face polish a good side, assuming there is one, with a flat lap, which I don't own yet.
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Post by Hard Rock Cafe on Dec 10, 2012 19:38:16 GMT -5
Good advice from John and Daniel. I also start my Lakers in a rotary, but use a UV-18 for every step after that.
You can spray the pits out with high pressure, either from a dry cleaning gun or a hose with a cap that has a very small hole in it. Or you can go after them with a brush.
Chuck
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hbonly
off to a rocking start
Member since December 2012
Posts: 7
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Post by hbonly on Dec 10, 2012 20:56:56 GMT -5
Thanks for the replies! I'm not sure that I want to rotary tumble them as I really appreciate their original form, but will do better getting rid of most "pits" on my subsequent batches. My wife Terry and I have been finding a lot of Lakers up near Moose Lake, The Agate Capitol of The World, in Minnesota. The largest Superior agate in the world at 108 lbs. is on display at a bank in Moose Lake. They also have "Agate Days" once a year, where they line Main St with 400 to 600 agates mixed in with other rocks and quarters and just let the people go at it. Check out Moose Lake Agate Days on Youtube. Another question, if I have only about 1/2 of my UV-18 full, should I add some of the ceramic pellets I got from Shawn at The Rock Shed to enhance the tumbling?
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herchenx
Cave Dweller
Member since January 2012
Posts: 3,360
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Post by herchenx on Dec 10, 2012 21:00:14 GMT -5
yes definitely fill the vibe. In the UV10 I fill it to the top edge of the center volcano thing before I start it, ceramic works well.
Moose Lake Agate Days sounds awesome.
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Minnesota Daniel
freely admits to licking rocks
A COUPLE LAKERS
Member since August 2011
Posts: 891
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Post by Minnesota Daniel on Dec 10, 2012 23:42:32 GMT -5
You must fill the Ultra Vibe tumblers or they won't work at all. It will likely damage the rocks if you don't. Fill to at least 1/2 inch from the top of the cone.
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