Help!

In a vibe, 220 is the coarse grind. There are three stages in a vibe.... 120/220, 500, and polish. Also, there should be rapid movement of the rocks. If they slow down, use a spray bottle full of water to get them moving again. If this doesn't get them moving, it could be due to too much slurry. In this case, time to re-charge. To me, it also sounds like it's time to move to the 500 grit stage.
Oh, one more thing, the vibe should be filled to more than half, but not quite 3/4 full.

You think? They still seem a little to scratched from the coarse grind to move to the 500 step.

I don't have a vibe - so take this with a grain of salt - but you said you were using 1 1/2 Tablespoons of grit per pound, 3 pounds total. Does that mean you used 4 1/2 Tablespoons of grit in the vibe? I was under the impression that vibes needed less grit per load than rotaries....

Also, I have to wonder about the plastic pellets. I have never used anything but ceramic.

The grit on the bottom usually occurs with too much warter or with too big rocks w/o enought small filler. In other words the grit falls down through the spaces. You want a thin slurry that washes away if you spritz the rock, but which then recovers the rock in a second or so. If you art much thicker than that, likely too much grit.

Given that the vibe is optimized for the weight of a full barrel, I would venture to say that if 30% to 50% of you barrel is full of light-weight plastic, then you might not be getting very efficient vibration. Ceramic helps give the proper weight in addition to serving as small filler.

In a rotary the pellets are about cushioning and not so much grit carrying. In a vibe they are about grit carrying and weight. Not really about cushioning at all - except that an underweight barrel may vibrate too much and cause problems.

As a lot-o user I had a similar problem for a similar reason...too much water.
Once my barrel is full, I fill it with water, then turn it upside down and strain out every drop of water I can. Only occasionally have I then had to add a few drops of water to get everything moving.

Clear out your barrel every 24 hours when using 220 and repeat the process. I run my rotary tumbled rocks for 2 days in 220 (changing the grit and clearing the barrel after 24 hours).

After 12 or so hours I usually add about a 1/4-1/3 of the red lid full of water just to get things moving again.

Mike

I always sprinkle until I see the right appearance of grit clinging to th edamp rocks. I find it varies a bit with the size of rocks and ratio of rock and ceramic.

Back when I started, I did go more or less by the guidelines given by the Rock Shed. they recommend 2 tablespoons for the 120/180/220 - or whatever is used for course. For medium (500f) and polish, they use only 1/2 teaspoon - a big step down.

www.therockshed.com/instructions1.html#Lot-O-Tumbler

I tend to put closer to a full teaspoon of 500, but I hav eto spray a little more water in about 2-4 hours. Who knows, maybe I was wasting grit.

RockShed seems to recomend proportionately more for the Thumler UV-10. I would expect about 4 tablespons, but they say 6oz, which I think is between 5 and 6 tablespoons. Depends on the grit size because a tablespoon of 120 weighs more than a tablespoon of 220.

Bottom line - if you get a thick cream that cannot be spritzed away for a second, then you have too much grit, or it is time to change it. (Ground rock makes mud which thickens even the proper amount of grit.)

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Since you say the batch needed very little filler/pellets, I jus tcaution you that the range of sizes of the rock is kinda important. Perhaps you have a good range of sizes. When I started I did mostly shapes cut form flat slabs and they wer all about the zise of a quarter or larger. I found I need between 40% and 50% ceramic because of all the flat surfaces. I was surprised.

It is very easy to underestimate the importance of the small rounded pea-gravel sized rocks. They really charge the load.

The plastic pellets may be doing this job, I just cna't say fo rsure. RockShed flat out says they are not recommended, but does not explain.

deb193redux,
I think I have a good enough size mix on this batch of rocks. This batch was busted with a hammer and I pretty well threw every little piece into the rotary, so what I put in the vibe ranged from a couple of millimeters up to a couple of centimeters in size.

Jack,
Sent you an e-mail.

Lee