leo
off to a rocking start
Member since August 2009
Posts: 6
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Post by leo on Sept 6, 2009 21:20:42 GMT -5
I'm pretty new to tumbling with a whopping 3 batches under my belt (3lb Lortone). I've not been unhappy with my results (I promise to post pictures soon), but as a scientist I want to know more. Apologies if these have been answered repeatedly, I didn't find them, maybe I'm not asking the right questions. Anyways, - Grit composition - I've been using the Rock Shed starter pack; SiC for rough, AlOx for (pre)polish. I've guessed that SiC is pretty standard for rougher grits, but I've heard differing things about Tin Ox and CeOx for polishing. Do these give a finer polish? are faster? better for certain stones? just a status symbol?
- Recharging - I've figured out that the rough (60-90) stage can take longer than the stock 7 days and the grit can break down and needs to be recharged. When you recharge, do you flush the barrel and start over w/ new water and grit, or just add fresh grit to the slurry you have?
- I'm starting to reuse the fine (AlOx) polish. I save the slurry, dry it at low (180F, 82C) temp in a convection oven until the H2O is gone then use a 3:1 mix of old:new polish for the next batch. Any problems with this? Can I do the same w/ the prepolish AlOx?
- I know that I shouldn't have only larger stones in a run, especially w/ a small tumbler like mine. Would adding plastic pellets be a good substitute, or do I really just need to have smaller stones in there?
I appreciate any insight people can give, this board and its members have already been a great help (and inspiration, I'm already designing my own tumbler design in my head). |
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MikeS
fully equipped rock polisher
Member since January 2009
Posts: 1,081
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Post by MikeS on Sept 6, 2009 21:45:15 GMT -5
Hi
Certain polishes are more suited for different materials and/or different polishing techniques. Cerium oxide is well suited for materials like quartz and glass, and is a decent polish for use on a leather wheel, but it doesn't always polish some other materials well. Tin oxide is pretty much suitable for most materials, but it is also more expensive than most polishes. Aluminium Oxide is a good all around polish, and tends to be the one you see most commonly used.
Recharging...I tend to rinse my rocks off when I recharge the coarse grit, because the slurry will slow the grinding action down.
On reusing the AO, personally I wouldn't mess with it for a number of reasons...one, it might be contaminated with small particles of rock that will scratch your next batch, leaving a more dull finish on them. Two, AO is pretty cheap, I'm not sure the money you'd save in the long run would be worth the time it takes to recycle it.
A good filler for both rotory and vibe tumblers alike are those plastic tile spacers you can get at any hardware store. They are cheap, durable, and easy to find.
Hope this helps...
Mike
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Post by johnjsgems on Sept 7, 2009 15:06:33 GMT -5
If you had a dedicated polish barrel you could keep using the polish until it no longer polished. A good grade of polish should require no more than two teaspoons of poilsh in a 3 lb. drum. After 5-7 days I don't think the polish would be too useful. Tumble grade Al Ox polishes run $5-$8 a lb. and submicron Al Ox $15-$20/ lb. After you build your monster tumbler you might want to reuse grit if it still looks useable. If you go the plastic route you have to dedicate plastic to each step as it embeds with grit so can't be mixed in other steps. You can also use gravel, ceramic media, rock scraps, etc. In the old days standard cerium was the polish for agates, jaspers, and many others. Tin worked etter on more types of rock. The Al Ox polishes available now will likely replace many of the others as they (in sub-micron range) cover a wider range of rock second only to diamond polishes.
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rockdewd
has rocks in the head
Member since October 2007
Posts: 605
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Post by rockdewd on Sept 9, 2009 12:27:39 GMT -5
When I wash out tumblers I put the barrel in the slop sink that drains out into my back yard or another sink I can roll out to the front yard on warm days. It all depends on which yard needs to be watered.
I place the barrel in a smaller plastic tub in the sink or under the drain of my frontyard sink (need to take pictures next time I wash out tumblers). I run water into the top of the barrel and pick the rocks out one by one. This is so the remaining 60/90 grit settles to the bottom of the barrel and what washes out is caught in the secondary plastic tub.
This way gives you a good idea of how the grit is breaking down and how much you need to add plus it conserves grit. This will only work with 60/90 grit. The finer grits flush away too quickly.
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