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Post by Jugglerguy on Jul 3, 2012 22:35:46 GMT -5
I'm having my first difficulty tumbling and I need some help. I've only been tumbling since December, so I don't have lots of experience. I'm trying to tumble Kona Dolomite and it's been going pretty well so far. I rough tumbled it in a rotary tumbler. No problem there. Then I half filled my Lot-O with Kona and filled it the rest of the way with mixed ceramic pellets. I used 6 tsp. 120/220 SC and 1 tsp Dreft. Since dolomite is soft, I knew I had to shorten up stages but I didn't know how much so I just guessed and did 9 hours. I washed and then did a stage of 500 AO, 2 tsp. Borax, and 1/2 tsp Dreft. I ran this for 11 hours. Then I washed and burnished in 1 tsp Dreft and 2 tsp Borax for 11 hours. At this point I noticed some undercutting on some pieces that had pre existing cracks or had quartz parts, but nothing too serious. I switched to a polishing barrel. I used 2 tsp Dreft and 1/2 tsp 1000 grit. It's been running two days. This morning it looked pretty good, but wasn't shiny yet. Tonight it was much worse. It's hazy whitish looking. It's much darker wet than dry. Wet: Dry: I have two questions. Where did I go wrong? What should I do now?
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Post by Jack ( Yorkshire) on Jul 4, 2012 0:48:08 GMT -5
I have never tumbled Dolomite but other softer rocks thatI have tumbled and have undercut I used a Buffing wheel and Zam
Its not a case of "where did I go wrong " but a simple fact softer material will grind faster than harder
I will leave this thread to be answered by those who are specalised in this field
Jack Yorkshire uk
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Post by Jugglerguy on Jul 4, 2012 6:39:11 GMT -5
Thanks Jack. My son and I have both used Zam to polish this stuff and it has turned out great. I'd still like to be able to have some success with a tumbler. The undercutting isn't really what I'm worried about. Some undercut, but others didn't. I'm much more interested in what made them get all hazy after they were doing pretty well.
Chuck (DrummondIslandRocks) posted a picture of a couple pieces that he did in a mixed batch that looked good. I know that his were done in a rotary tumbler. Is that the difference, or is it possible to have success with a vibratory tumbler too?
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Post by connrock on Jul 4, 2012 8:53:53 GMT -5
Although some people have good results using Borax I don't and haven't used it in quite a few years now. I use only Dreft Powdered Laundry Soap. I found that using Borax,,,especially with rocks that are made up of different hardness within themselves,,,I get exactly what you ended up with. Doing this type of rock can be very tricky and I have never been able to achieve a shine as "solid" as I have with agate and jasper. This rock is very similar to yours and was 1 of the rocks that was part of the 1st rock tumbling competition. You can see that there are a LOT of flaws in it and also parts where the surface has undercutting and overlapping parts where the harder material meets the softer material and is "flaking" off slightly. Although it looks like there is trapped grit and or polish,,,this is NOT the case.There is NO grit or polish in these areas it is only the characteristics of this type of rock. This is an extreme case and why I chose this particular rock to try to show what happens whenthis type of rocks is tumble polished. I should add that these rocks were roughed 8 or 9 times in a rotary and finished in a Lot-O. This is the entire load after polish and as you can see there were a LOT of this type of rock in the load which made it EXTREMELY difficult to polish. You can view the entire load from start to finish,with a small description of how the load progressed,here,,,,, imageevent.com/tcknkk/comprocks2009?n=0&z=9&c=3&x=1&m=24&w=0&p=0connrock
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jspencer
freely admits to licking rocks
Member since March 2011
Posts: 929
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Post by jspencer on Jul 4, 2012 22:20:14 GMT -5
Just my opinion but the time you ran it is not sufficient to do the job. The shortest cycle I ever run is 2 days minimum. Stones that tend to undercut I usually leave them in 500 for 3 days run then prepolish for 2 days and I leave all my loads in polish for 5 days. I also run vibe as dry as I can and still achieve good tumbling action. I am no expert though. Maybe just lucky to this point.
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Post by Jugglerguy on Jul 4, 2012 22:26:10 GMT -5
Thanks for the advice Connrock. It was actually your recipe that I was trying to follow. It's been working well for me so far, so thanks.
I wasn't using Borax when things seemed to go bad, but I had used it in the couple steps before, so maybe the damage was already done and just wasn't evident yet.
I looked at your competition pictures. I had seen these before, but now that I have a little more experience, I learned more rereading it. Those sure ended up nice, considering the flaws in them!
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Post by susand24224 on Jul 5, 2012 0:38:42 GMT -5
One more thought for you and an additional comment. The haze could be caused by mixed hardnesses in your rocks. Do the quartz veins have the haze?
Also, along with Connrock, I have had borax haze very soft rocks. It has worked fine for me on harder rocks, but has caused hazing on fluorite and turquoise.
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Post by Jugglerguy on Jul 5, 2012 6:22:41 GMT -5
I'll have to check on the quartz parts. I know I'm not supposed to tumble mixed hardness rocks, but what about the ceramic media? Why are there no warnings about tumbling soft rock with hard ceramic?
I've got some more Kona still in the rotary in 60/90. I think I'll retumble my hazy stuff in 60/90 and then put it back in the Lot-O with the quartzy pieces pulled out and no borax.
Does everything else sound Ok? Jspencer, I was writing my last post at the same time you were, so I didn't see you reply. I thought that since my rock is soft (Mohs 4) that I should tumble it for shorter times. I usually tumble stuff for a day or two or three in each stage.
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Post by susand24224 on Jul 5, 2012 17:11:15 GMT -5
What I have read about ceramic media is that although it is harder than some rocks, it is considerably less dense so does not cause a problem. I have no idea if this is correct, but I've never felt they damaged any of my softer rocks.
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