dom92
off to a rocking start
Member since September 2008
Posts: 8
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Post by dom92 on Sept 25, 2008 16:01:52 GMT -5
I've now run two 6 pound loads through my Loretone tumbler. Course 2 weeks, fine 2 weeks, pre-polish and polish 1 week each. Some of the rocks are beautiful, but about half of them get polish in to some of the cracks that I just can't seem to get out and it makes them look awful. The rocks are assorted, some amethyst and some of the Rock Shed's " crushed mixed rock." Initially I started thinking that maybe I just wasn't running them long enough in the course and fine stage, but they're as smooth as they can be, there's just little fissures in some of them that all the tumbling in the world won't remove.
So I guess my question is whether this is due to the types of rocks I'm using or if it's a problem of the polish? I'm not sure of the polish type, but it's the fine white powder that comes with most grit packs. Would running them through a cycle with the borax soap some people use get rid of any remaining polish?
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Post by connrock on Sept 25, 2008 17:33:03 GMT -5
A Borax wash won't hurt but I suspect it's the rocks themselves.
Once those fractures get loaded up it's almost impossible to get it out.The rocks have been taking a pounding for a long time and the grit/polish gets packed in the fractures over and over as the rocks tumble.
In each step of the tumbling process the grit gets finer and then the very thin polish is used.This worsens the problem because the fine grit/polish really packs in the fractures and looks like a white crack.
I took a few rocks just like yours and hit the fractures with a VERY high pressure gun to see if I could cure the problem.
I got the grit/polish out and the rocks looked worse then before having big empty fractures.
It's best to stay away from rocks that are typically fractured and or pitted.Amethyst can kill you if the rough isn't of good quality.The deep purple makes the grit/polish filled fractures stand out terribly.
Another point about poor rough and especially rough with a lot of fractures is that those fractures carry a LOT of grit into the next step and can raise havoc with the load.
Just for the heck of it carefully crack your worst looking rock at one of the fractures and look through a jewelers loup or any magnifying glass and you'll see what I mean.The fracture will be LOADED with grit/polish.
connrock
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dom92
off to a rocking start
Member since September 2008
Posts: 8
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Post by dom92 on Sept 25, 2008 19:20:26 GMT -5
That's what I was afraid of, but I appreciate the advice. At least I know I can toss them out as garden rocks rather than waste more grit and polish on them.
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Post by deb193redux on Sept 25, 2008 19:27:58 GMT -5
I think you need a mix of runing longer in course, and not moving all rocks on to medium (get out those cracks, or break up cracked rocks).
Keep the bad ones in course until they disappear. You will take much more satisfaction form batches that only move well shaped and smooth rock on to higher stages.
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dscratch
starting to spend too much on rocks
Member since June 2008
Posts: 214
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Post by dscratch on Sept 25, 2008 22:02:52 GMT -5
When I run my batches, I pull out the stuff with pits and toss it in a small pail. Then I toss them in some more rough grind. The one exception is when I tumble fire agate. I find it nearly impossible to get the little pits out of those. The polish isn't as noticeable on fire agate so it's not too bad.
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dom92
off to a rocking start
Member since September 2008
Posts: 8
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Post by dom92 on Sept 26, 2008 17:40:17 GMT -5
I think what I may try with my next batch of Amethyst (since it tends to have a lot of cracks that show polish residue so badly) is only run it through the pre-polish cycle and then see if I can polish it up by hand using my Dremel and a polishing attachment. I figure it's worth a try.
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rollingstone
starting to spend too much on rocks
Member since July 2009
Posts: 236
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Post by rollingstone on Sept 27, 2008 2:50:50 GMT -5
Could be a number of things going on, perhaps the rough rock, but I'd have to agree with 193 redux that 2 weeks in coarse is not long enough. I usually go about 6 weeks in coarse for amethyst, cleaning and recharging weekly.
And for the polish that gets stuck in cracks... definitely use a cleaning stage if that is an issue (I use cleaning stages as a matter of course between the various grinding stages). And remember to never let the stones dry out until they are fully polished and cleaned -- any polish that dries will become permanent cement and you will never remove it. If it is kept wet, then a "burnish" with borax or ivory soap has a good chance at removing it.
I wouldn't bother with the Dremel polishing of each stone, unless you have tons and tons and tons and tons of idle time on your hands. :-)
-Don
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dom92
off to a rocking start
Member since September 2008
Posts: 8
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Post by dom92 on Sept 27, 2008 8:14:06 GMT -5
I understand what everyone is saying about giving it more time in the first stage. The problem was/is, that I was losing so much of the rock after two weeks, it was going to disappear. For instance, I started out with some pieces of amethyst that were maybe half the size of my thumb. At the end of two weeks in the course grind and two weeks in the fine, many of them were now the size of peas (and yet still had cracks in the them). Basically I don't think I could have ground them much more, because once a crack disappeared another one emerged. I think I just had poor quality amethyst for this batch.
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Post by deb193redux on Sept 27, 2008 15:03:11 GMT -5
yes, sounds like lots of macro-crystal in the amythest. the only way you get that kind of reduction in two weeks is from breakage not abrasion.
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Post by Jack ( Yorkshire) on Sept 28, 2008 4:06:55 GMT -5
Hi Dom62, Can I ask about your load ? Is it all big rocks or do you have a good cross section of rocks especialy small for getting into the cavity concaves ? As others have said a longer time in the first 4 to 6 weeks at least with Agates. But with fractures and holes  they just hold grit till they get you over to the polishing cycle --- then they let go Grrrrrrrrrrrrrrrr Have a good day Keep at it you will suceed Jack Yorkshire UK |
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Post by LCARS on Sept 28, 2008 12:38:31 GMT -5
I'm going to reitterate on a good point that Don made.
DO NOT let the rocks dry out between pre-polish-polish stages.
This makes a big difference when doing the final wash cycle with borax/ivory after final polish. Most of the material in the cracks will come out in a final burnish cycle if it hasn't previously dried.
This takes some extra effort and forethought betwen stages. I just dump my whole load into a collander with a plastic basin under it to recover the slurry and then immediately put it aside and rinse the rocks in the collander, keeping them submerged in another basin until putting them back in the barrel. Also, do not use too much polish. I find that 1/2-2/3 tsp/lb is plenty, less excess compound to get stuck in the cracks.
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dom92
off to a rocking start
Member since September 2008
Posts: 8
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Post by dom92 on Sept 29, 2008 1:21:13 GMT -5
Hi Dom62, Can I ask about your load ? Is it all big rocks or do you have a good cross section of rocks especialy small for getting into the cavity concaves ? As others have said a longer time in the first 4 to 6 weeks at least with Agates. But with fractures and holes they just hold grit till they get you over to the polishing cycle --- then they let go Grrrrrrrrrrrrrrrr Have a good day Keep at it you will suceed Jack Yorkshire UK I had one 3 pound barrel with all amethyst, and one 3 pound barrel with mixed rock. The amethyst and mixed rock were all about the same size, no more than 1/2" diameter on any of them. I'll definitely follow everyone's advice about not letting the rocks dry between cycles. I'll see if that helps me the next time around. |
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Post by Jack ( Yorkshire) on Sept 30, 2008 7:50:45 GMT -5
Hi Dom 62,
3lb barrells are SLOW I used them when starting , then used 6lb paint tins what a difference
Its the weight of the stones that make the difference, I then got a 6lb Lortone which I use now befor Vibing them in the Lot"O" to a finish
In the 3 LB barrels give them some more time in the first stages if you want a good finish it can be done but it takes a lot more time , and when you start polishing You just havent got the time !!!!!!! Paitience Patience !!
Have a good day
Jack
Yorkshire UK
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tombodc
noticing nice landscape pebbles
Member since August 2008
Posts: 88
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Post by tombodc on Sept 30, 2008 18:36:05 GMT -5
do not use too much polish. I find that 1/2-2/3 tsp/lb is plenty, less excess compound to get stuck in the cracks. 1/2 -2/3 teaspoon per pound? Really? Sorry if that is a newb question. I was figuring on using 2-3 table spoons in my 1.5# barrel... |
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