learn2turn
noticing nice landscape pebbles
Member since February 2011
Posts: 77
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Post by learn2turn on Apr 2, 2011 20:28:47 GMT -5
Does anyone have some rules of thumbs, pictures even better, for when rock is ready to go to the next step?
I'm a beginner now trying some batches of cheap mixed tumble rough.
The batch I have in the rotary has been in 60/90 grit almost two weeks and hasn't gotten very smooth or rounded at all.
I have some small rock I started in a toy tumbler in the first two grit stages. I don't know if it's gotten enough of the second stage to go 500 pre-prolish. It's got kind of a matte satin finish.
I have some beach stones in the vibe in 120/200. They started round enough. I just need to know how smooth they have to be to go to the next step.
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blr2449
has rocks in the head
Can I retire now?
Member since January 2011
Posts: 554
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Post by blr2449 on Apr 2, 2011 21:04:56 GMT -5
I just checked mine today, too, after almost 2 weeks in the coarse grit. The edges and corners are starting to round out, but nowhere near where they should be.
I also noticed the slurry was watery with not much left on the bottom of the barrel. So I added more of the coarse grit and started them back up. Will probably let them run for another 2 weeks. It's a barrel full of agate, so it might more than 2 weeks.
I usually check them every week to see if more grit needs to be added.
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MikeS
fully equipped rock polisher
Member since January 2009
Posts: 1,081
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Post by MikeS on Apr 2, 2011 21:39:44 GMT -5
It all depends on what kind of material you are tumbling, and how smooth or rounded you want the finished stones to be. Some people like to leave lots of the natural shape on the finished stone, others like a more perfectly rounded end product. Harder material obviously usually takes longer than softer materials. As a good rule of thumb, check them every 10-14 days or so, try to tumble off all the sharp edges that may scratch other rocks in the later stages, and keep tumbling them until you are satisfied. I've had batches I've kept in the coarse grit for 2 months, and others I was happy with after only 10 days....
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Post by susand24224 on Apr 3, 2011 1:13:51 GMT -5
I agree with MikeS that how rounded the rocks are is a matter of personal taste. But, in 60/90 at minimum be sure the surface of the rock is smooth (no small pits or cracks). Grit can get stuck in these and ruin the batch in a later stage.
I have had agates go for months in 60/90, so I wouldn't worry about two weeks.
For later stages, I'm not as sure how to tell you how to know when they are done. They just feel different to me, which I know doesn't help much. Most of the hard work is done in 60/90, though, so if you run your next stages 7-10 days you likely won't go too far wrong. Two other things you can do to be sure: (1) save a rock or two out of 60/90. With a magnifying glass or loupe compare the tiny little scratches on the 60/90's that you didn't put into the next stage with the ones you did. You should be able to see the difference in the size of the scratches, and *all* of the 60/90 scratches should be gone. (2) If you are tumbling Mohs 7 rock (most mixed "kits" are primarily Mohs 7), after 500 grit you can slightly dampen the rough side of a piece of leather and put some polish on it. If you rub the rock vigorously over the polish for a minute or so, it will polish if it is ready for the polish stage.
Hope this helps.
Susan
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learn2turn
noticing nice landscape pebbles
Member since February 2011
Posts: 77
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Post by learn2turn on Apr 3, 2011 7:15:50 GMT -5
Okay, so the 60/90 stage is mostly when satisfied with shape. I think the batch I have in 60/90 now is really watery. Maybe I should pour some water off? Add another teaspoon of grit.
It's the next steps that I need to learn more about.
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Post by tntmom on Apr 3, 2011 14:04:27 GMT -5
Does anyone have some rules of thumbs, pictures even better, Hi Learn2turn, You mentioned that pictures might be helpful. For a general idea, here is some agate that I started in 60/90 on February 24th. Here are the same pieces 5 weeks later. As you can see, they are beginning to take on a smoother more rounded shape but are still full of pits. These rocks are going back in for at least another month or until I see no pits at all. Hope this helps! ~Krystee
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learn2turn
noticing nice landscape pebbles
Member since February 2011
Posts: 77
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Post by learn2turn on Apr 3, 2011 16:30:47 GMT -5
These are some Puget Sound beach stones I bought off ebay for about $11 for 5lbs shipped. They been in the vibe in 120/200 for a few days. I took them out and washed them to check them. Actually, they look really great, much better than the photo. Only one or two of them have tiny low spots that are a bit rough. All the rest are very smooth. I'm thinking I'll do another few days 120/200 just for good measure and then go onto the next step. I selected from the stones I bought about 1/2 with few or no ridges or pits so I didn't have to do a 60/90 step in the rotary first. I had the vibe just sitting their so I wanted to try to do something with it.
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stefan
Cave Dweller
Member since January 2005
Posts: 14,113
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Post by stefan on Apr 3, 2011 18:13:37 GMT -5
You got the general idea. Very rarlywill you encounter a rock that running to long will actually do any harm. Sometimes my rocks will run months in course. I run 2 week cycles for all the other stages. There really is very little actual grinding past the 120/220 stages. You are basically just removing the previous stages scratches
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Post by Jack ( Yorkshire) on Apr 4, 2011 9:47:31 GMT -5
Hi STAGE ONE,
I run my rotary for 6 days it is a home built on and runs at 42 RPM , at day 6 the grit is out so I was up and add another charge of grit for another 6 days
I used to run longer and more grit until I experemented and ended up with this method , this system works well for ME every one has there own method and through time you will also have yours
Keep a record as you go and then you will see and know which method or adatives worked the best for you
Just keep asking , as they say on here the only dumb question is the one that isent asked,
We all started out once and all made mistakes
Jack Yorkshire uk
Ps from stage Two in the Lot"O" Vibe
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