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Post by Hard Rock Cafe on Jun 30, 2009 19:38:33 GMT -5
The below advice pertains to my experiences with a Thumler's Ultravibe UV-18, but should apply to all tumblers of similar design (not the Lot-O).
I've learned the hard way that if the bowl is under-loaded, I will get a matte finish on the rocks. If the rocks are bouncing up and down instead of churning, your vibe is under-loaded. Even if they are mostly churning, but they're bouncing up and down at the top of the cycle, then your vibe is still under-loaded. The rocks are essentially acting as little ball peen hammers and creating micro fractures in the surface of the rock. Through a magnifier, it looks a little like the surface of an orange or a golf ball, but on a much smaller scale.
It is very difficult to over-load my vibe. In fact, I've had it so full that the rocks of rubbed against the lid, but still polish fine.
Key indicator: the rocks will look great wet, but dry them off and you'll see the matte surface.
In my experience, it helps to have ceramic pellets to top off the load, but you could probably use plastic pellets, tile spacers, or small pieces of rock (which is what I plan to do on my next run). I have several pieces of chert/flint that I had planned to cut, but turned out to be too fractured. So, now I'm breaking them up into pellet-sized pieces.
Hope that helps somebody.
Chuck
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Post by Bikerrandy on Jun 30, 2009 20:18:58 GMT -5
This is true!! One of the things that I do to help my polish stage is dump a load of finished rocks from one of the previous batches in the vibe to ensure that the rocks are filled to just above the stripe on the bowl. I've heard of people using marbles too.
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Post by johnjsgems on Jun 30, 2009 20:54:05 GMT -5
Guess I'll stick with ceramic media. I lost my marbles a long time ago.
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Good Vibrations
noticing nice landscape pebbles
Overanalysis leads to Paralysis
Member since May 2009
Posts: 91
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Post by Good Vibrations on Jun 30, 2009 21:44:25 GMT -5
That's funny John, I lost mine too..... I filled my vibe to the point that the pellets jumped over the edge when I took the lid off. This may be causing slurry to leak out though too. I'm still trying to find out what the right level is.
When I first start a new grit cycle, I watch with the lid off for a couple minutes, and it seems like it takes the rocks a minute or so to start their churning motion (up the outside & down towards the middle). At first they just rotate in a horizontal circle.
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Post by mohs on Jun 30, 2009 21:47:16 GMT -5
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Post by Hard Rock Cafe on Jul 1, 2009 12:31:54 GMT -5
Yes, it does take a little while for the rocks to settle into the right rhythm.
Me, too, John, although I think I have a real (antique) aggie or two around somewhere.
Chuck
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Post by MyNewHobby on Jul 2, 2009 16:19:08 GMT -5
Still being on my first vibe batch and checking everyday (now in the final polish) I have found some that have that matte.
However ... I have finally gotten the batch to do the "roll" thing. Up the side and down into the middle.
Mostly, the ones I am getting the matte on are usually the picture and some red jaspers.
Thanks for this tip ... I think that I need to add this to my notes as I am still such a beginner.
As always
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Post by MyNewHobby on Jul 2, 2009 16:21:03 GMT -5
Oh .... another question ...
Does this issue also apply to the burnishing process?
I wonder due to the fact that I think more water is to be used with the borax. As I watch periodically, I see the water jumping up and down just as you have described as a "ball peen".
As always
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Post by Hard Rock Cafe on Jul 2, 2009 20:45:02 GMT -5
With burnishing you usually have a lot of water (compared to grinding or polishing) so it is not usually a problem, although I suppose it could be. I'd be less concerned about the water jumping up and down than the rocks hammering against each other.
Chuck
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Good Vibrations
noticing nice landscape pebbles
Overanalysis leads to Paralysis
Member since May 2009
Posts: 91
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Post by Good Vibrations on Jul 2, 2009 21:39:03 GMT -5
With burnishing you usually have a lot of water (compared to grinding or polishing)... Chuck Oh really? I missed that info somewhere along the line here. I wonder if that's why my second batch got all banged up in the Borax. The only water I added was sprays from the squirt bottle. I did use the ceramic pellets though. Thanks for starting this thread Chuck, and thanks for asking 'another question' Julie, - it's definitely helping me! |
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firstrune
starting to spend too much on rocks
Member since January 2009
Posts: 156
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Post by firstrune on Jul 3, 2009 16:36:06 GMT -5
Chuck, another great piece of advice to tuck away with getting the vibe right.
Thank you for this!
Bonnie
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Post by Jack ( Yorkshire) on Jul 4, 2009 1:38:03 GMT -5
Good advice Randy
I always fill up , then run and fill up again running(stage2) and as I go through the stages they do grind "off" and there is more room in the container,
So I would say start really full so you will end up with a full load
Its a good Idea to add polished rock to fill up as Randy says if you do loose too much load
jack
Yorkshire uk
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Post by connrock on Jul 4, 2009 6:50:11 GMT -5
I've never run a vibe other then the LOT which has a rubber barrel that has nothing in the center to deflect the rocks back into a rolling motion as I see other vibes have.
It seems to me that the action is totally different between the 2 different types of units and I think with all the new people we have starting out with vibe units this should be taken into consideration.
There seem to be some common basics with all units and 1 is to try to keep the barrel as full as possible either with rocks or other media.I personally don't like all rocks in my pre and polish stages.I use a LOT of ceramic media in both stages and have had some very good results doing this.
One thing about the LOT is that the more water you use the more gentle the action will be.This type of gentle action works very well when doing obsidian.It is suggested by the manufacturer that when doing obsidian one should cover the rocks with water which is usually a BIG no no with a vibe.
However he manufacturer has done it's home work on this one and it works great.
I guess what I'm trying to say here is that when we are giving help to others here it should be understood that what works for one brand unit "may" not work for another.
If I had the money I would buy a brand "X" ;D so I could make comparisons for all!!
Good luck and D O N O T give up!!
connrock
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Post by Hard Rock Cafe on Jul 6, 2009 11:28:31 GMT -5
Good point Tom. I've modified the original post.
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