Mazanec
spending too much on rocks
Member since March 2004
Posts: 355
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Post by Mazanec on Apr 29, 2004 11:42:26 GMT -5
How does the amount of grit used affect results? What if I use 2 ounces or half an ounce instead of one ounce (for example). Are the stones just more or less rounded after the cycle? Does the cycle last 5 or 10 days instead of a week? What changes?
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Post by cookie3rocks on Apr 29, 2004 19:05:52 GMT -5
I use the instructions that came with my grit and for coarse to pre polish it's 1 1/2 onces per pound of rock. I would think the hardness of what you are tumling may affect that though. And now I know that I should mix the grit and water before adding the stnes so it doesn't settle at the bottom of my vibe. Te polish stage gave no instructions I just know I don't need to use as much. ;D
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WilliamC
spending too much on rocks
Member since August 2003
Posts: 416
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Post by WilliamC on May 2, 2004 19:48:00 GMT -5
Greetings All,
It depends on the Mohs hardness of the rock and the sizes of the pieces you're starting with. The hardest rocks I've tumbled so far have been agates and jaspers, which can be a bit harder than pure quartz, or 7 on Mohs scale. Also, I'm tumbling the first stage in a QT12, so I can get up to one fist-sized rock in it. That said, I've got a couple of max pieces of jasper and agate that are taking over 5 weeks in the 60/90 grit, using 2 cups grit per week, with the grit being completely used-up each time, and I'm still not ready to pass them up to 120/220. I've also tumbled same size pieces of verdite (Mohs hardness ~5) and after two weeks using 1 cup grit, with some grit left in the barrel, they are ready 0or 120/220. Even though the verdite is dense and much harder to break than agates/aventurine/jasper (it doesn't seem to want to fracture as easily, it just breaks and pulverizes) it grinds away much easier.
Anyway, for a rock of hardness 6 or better I'd try with two cups grit for one week, and then see if the grit was used-up or not. Adjust downward accordingly, but I'm not thinking to use more than the maximum recommended at one time just so as not to waste it.
WilliamC
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