True Grit
noticing nice landscape pebbles
Member since January 2013
Posts: 76
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Post by True Grit on Feb 28, 2013 14:32:42 GMT -5
These are from my very first tumble with my Diamond Pacific MT-4 vibe tumbler. I'm looking for a reason why these, (and most every stone in this batch), have these cracks, it looks as though each one was hit with a hammer, (these are about the size of a nickel, I'll put a reference in next time). After every stage I would burnish This is the first time using this tumbler so I would then let everything dry so I could weigh. (I just want to see how much is lost at each stage, I'm weird I know). Things were looking great after the pre-polish no cracks I could see. 2 days in the polish I find all these fractures, cracks, you name it, (the picture has 2 rocks I've been watching from the start so I'm pretty sure the fractures were not there going into polish),. I followed the manufactures steps for weight and grit amounts. As each stage went I added ceramic fill to keep the weight right. Then like I said after 2 days in polish I get these chips, cracks, etc. The stones in the pic are emeralds I'm running another batch tomorrow with a bunch of 7's, (not emeralds). I'm thinking should I slow the vibe down? I don't know does anyone have any thoughts, ideas... help? Thank you for your time. Tim Attachments:
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Post by Toad on Feb 28, 2013 14:43:42 GMT -5
What are the stones? If it is fluorite, they are very soft - which I'm thinking is the case since you got well-rounded shapes in a vibe. Sometimes just depends on the quality of the stone as well, maybe they just couldn't take one more round in the vibe - which is a very harsh environment. a few more details would help.
As you suggested - lower speed might help. More cushioning with ceramic or plastic media. Vibes are meant to run full!
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Minnesota Daniel
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Post by Minnesota Daniel on Feb 28, 2013 15:50:25 GMT -5
The rocks are fracturing - smacking into each other with too much force - but apparently only in the polish stage. There could be a lot of reasons why rock might fracture in a vibe tumbler, but the only relevant question in this case is why did it appear to happen in the polish stage and not earlier. First off, were the fractures there all along and just not visible until they were polished? I think you covered that, so what was different in the polish stage?
I assume you filled it the same - rock, filler and water. A vibe tumbler is supposed to work by having the rocks vibrate against each other, not smack. The pre-polish and polish keep the rocks from actually touching each other. They act as a sort of lubricant too, like graphite, except wet. Obviously the pre-polish and the polish were different. Maybe you need to use more polish. What about soap, borax, etc? They enhance the slipperiness, like oiling a (hand) saw, or the oil in a rock saw -- it makes it cut better/faster. I use a UV-10 vibe, not your vibe, but I have at times thought the rocks were making too much of a "clinking" kind of noise, so I added more soap. Powdered dish washing detergent actually. There was an immediate softening of the noise and a visible difference in the movement of the rock. I can see them slide against each other more smoothly. Bear in mind, the polish is right in there still working.
I assume you're using ceramic filler. Maybe when you get to the polish stage you need to use more of the small filler and less of the larger filler. I'm pretty sure you'll be able to see a difference between the two in the way the rock moves in the barrel.
Just some ideas to consider.
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True Grit
noticing nice landscape pebbles
Member since January 2013
Posts: 76
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Post by True Grit on Feb 28, 2013 16:09:40 GMT -5
Thank you, I bet you hit the nail on the head. I remember it was noisy in the polish, but I thought..... That makes sense Daniel (?). Thanks for the education. I was worried about the ceramic in the polish stage but I needed the fill. Next time I'll wait or I may try using some plastic pellets as I move through the stages.
Let me ask this question, what matters more weight or volume ? in a tumble?
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Minnesota Daniel
freely admits to licking rocks
A COUPLE LAKERS
Member since August 2011
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Post by Minnesota Daniel on Feb 28, 2013 16:15:36 GMT -5
Volume. Probably slow it down if you think it might be too light. I think you almost always need to use ceramic filler in a vibe. It helps make it "flow" correctly, not just to fill it up. Try adding a little more soap while it's running if you think it's making too much noise. You'll definitely see and hear a difference.
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True Grit
noticing nice landscape pebbles
Member since January 2013
Posts: 76
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Post by True Grit on Feb 28, 2013 16:40:55 GMT -5
Ok, cool. I have a lot to watch for and do going into a second try. I was thinking weight, volume makes sense now. Alright then lets do it again!! Thanks again.
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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 Feb 28, 2013 16:57:17 GMT -5
Including a speed control I think means the tumbler was designed for range of weights. Ceramic filler is lighter than rock. It makes sense to me that if you run a load with a lot of filler you might need to turn it down.
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True Grit
noticing nice landscape pebbles
Member since January 2013
Posts: 76
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Post by True Grit on Feb 28, 2013 17:11:23 GMT -5
I was thinking the same thing. really if you wanted to I guess, you could run all filler with just a single stone/rock in the tumbler. As I start this new batch I'll pay more attention to my volume. how about fill size all the same or mix it up?
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Post by Peruano on Feb 28, 2013 18:04:48 GMT -5
I think you can tell a lot by watching and listening to your tumbler. When properly loaded the stones will roll from the outer edge up and into the center and down like a blender churning up a smoothy. If they sit there and rattle without rolling in a blender like pattern you have too much water, or perhaps too many large stones. If they jump around like popcorn you probably have too few stones, not enough moisture or grit, and need to add filler, ballast, or larger stones. I'd doubt that you did anything drastic in the polish stage as opposed to all the others. I sometimes way my initial batch to see if I'm near my correct capacity, but after that I just let it roll and if I feel thinks are getting violent (or fragile) I add a bit of ballast in the form of ceramic pellets, or rejected stones from the last run (if they don't have large pits and were rejected for being ugly). Your problem may be your stones being too soft, so you may want to run another batch with something with a known characteristic (even quartz will give you a basis for judging your loading and charging technique - but I'd suggest a variety of beach or river pebbles and then you will see who gets damaged, who gets shined, and who becomes fodder for the next run just as ballast. I think your stones have some appeal and maybe you are just in need of another run. I'm always pleased when I get some keepers, and have to remind myself that they all can't turn out premo. Adalante y suerte. Tom
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Minnesota Daniel
freely admits to licking rocks
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Member since August 2011
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Post by Minnesota Daniel on Feb 28, 2013 18:09:09 GMT -5
I think in a vibe a mixture of sizes is less important that filling it with smooth stuff that's smaller than the rock itself. If the objective is to get the most surface to surface contact then I think the smaller sized ceramic would be best. On the other hand, the "flow" of the load as it vibrates might require a mixture of sizes. That I wouldn't know. You might email the manufacturer and ask that question.
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True Grit
noticing nice landscape pebbles
Member since January 2013
Posts: 76
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Post by True Grit on Mar 1, 2013 9:55:36 GMT -5
Daniel, Tom Thank you both for your time and help. My next vibe roll will start today, (very soon really). I wanted to check this post before I start. I'm running these nice and slow to start. I'll keep eye on how the grit holds up. I will pay more attention to the sound as well. I think I know, now, what stones knocking the crap out of each other sounds like. Thanks again. I'll post as things move on. Tim
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jspencer
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Post by jspencer on Mar 1, 2013 22:45:41 GMT -5
The cyclone action discussed is the biggest thing to look for. Without the top on it it will rattle a lot, but if you place your hands on the side of the bowl opening it will steady it as if the top was on it. Keep your eye on a particular rock and see that it goes top to bottom as it goes around the bowl and not just sit on top and go around in a circle. Only spritz it with enough water in your mix to get the movement right, no more. Too much and the rocks ride on top and get banged up and not polished. A good mix of size I think is important too. But if doing quartz rocks they can bang each other up pretty bad with a far range of hardness. Even in rocks of same origin sometimes.
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