hoganflagle
having dreams about rocks
Member since April 2007
Posts: 62
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Post by hoganflagle on Oct 22, 2008 18:20:08 GMT -5
I have been kicking around the idea of attempting to rotary tumble shaped stones now that I seem to have grasped the basics of tumbling. I have a Workforce tile saw that I was going to attempt to cut some slabs then trim them into hearts. I was thinking of trying it out on Agate first before moving to Amethyst. I would eventually like to try to tumble some Moonstone pieces that are cut as crescents but think that may be a challenge as it appears that Moonstone in general is structured with fracture lines that may not cooperate.
Anyone have any success in doing shapes and what do you do different than when you do a standard rotary tumble? I assume you would use more plastic beads, and much smaller like material?
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Post by Michael John on Oct 23, 2008 0:37:16 GMT -5
Do 3/8" slabs. When you cut the shapes, GENTLY go around the edges with the side of the blade, near the blade edge where there's diamond, to just dull the sharp edges. That will help prevent chipping in the rough tumble stage. Any pieces that look like they might be fractured and break, leave them out. A broken piece could contaminate your slurry and send you backwards in the tumbling process. Don't leave them in the rough stage too long ... better to go longer in the second stage if needed. Always use plenty of pellets.
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Post by Jack ( Yorkshire) on Oct 23, 2008 2:18:04 GMT -5
Hi
As above
Also you can work out how sharp (Or soft) a edge you want as to how long you put them into the grit and at what stage
I use the Vibe now and that is quite helpfull
I would be VERY carfull when doing the Amythyst I had a disaster batch once due to fracturing and to fast a speed
I find the vibe is better (Lot "O") 3 1/2 lb model
have a good day
Jack
Yorkshire UK
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pebblepup
has rocks in the head
Succor Creek Thunder Egg
Member since July 2008
Posts: 515
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Post by pebblepup on Oct 23, 2008 10:56:47 GMT -5
When I do shapes and cabs I roughly shape the piece with a grinding wheel and 100 grit SC expando drum. Then I jump to 400 grit tumbling. For the most part this will give you a good finish before starting the polishing steps and retain the desired shape. I have had a couple of pieces that got stuck on other rocks and the shape was distorted.
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hoganflagle
having dreams about rocks
Member since April 2007
Posts: 62
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Post by hoganflagle on Oct 23, 2008 18:10:49 GMT -5
Thanks for passing on the tips and experiences. I plan on incorporating the advice. Will pass on how things went in about 2-3 months as I have to finish some current tumble loads while cutting and shaping the candidates.
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Terry664
fully equipped rock polisher
Member since March 2005
Posts: 1,146
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Post by Terry664 on Oct 24, 2008 23:00:58 GMT -5
I have done shapes using a WF and bench grinder, sometimes using a grinder. But I mostly use the WF, I use side of blade to smooth. I have done hearts, crosses, dolphins, butterflies, elephants, turtles, etc. I usually do 30-60 small pieces along with rather smooth and round rocks, filling barrel to about 1/2, then fill with plastic pellets to just below Lid. By the time I get to pre- polish I have no rocks with cracks, crevices, or vugs. I did some swords that were very thin, I have only broke about 4 pieces in tumbling. Also I would practice your hearts on something like granite, it is wonderful to work with. My basic formula is 120/220 with shapes very smooth and rounded rocks, run 1 week, but I check after 3 days. Then 120/220 with pellets, 1 week. Then 600 with pellets 1 week, pre-polish 2 weeks, then polish 2 weeks. Until I get to pre polis I check and see if any need touch-up shaping with Diamond Dremel burrs.
Terry
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Post by Bikerrandy on Oct 25, 2008 22:01:59 GMT -5
You'd be so much better off tumbling shapes in a vibe!! I got mine from Shawn...... www.therockshed.com |
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