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Post by tntmom on Nov 22, 2010 0:22:58 GMT -5
I know I've read about this somewhere here, but for the life of me I can't find it. I've been playing around and learning how to do small cabs by hand with a dremel. I've found a method that works great for me. I cut with a 40 grit diamond bur, grind and shape with a diamond wheel. Takes about an hour. Then I'm stuck. Regular burs in smaller grits gave me a hard time, skipping and gouging making deeper scratches than what I started with. I have diamond paste in 1200, 8000, and 14000. I used them, ignoring the scratches, and loved the felt burs! They work really quick too, less than 5 minutes per grit. I found Jade Carver from an old post here that sells the diamond compound starting at 120 grit up to 50k. I will be placing my first order with him tomorrow for the lower grits. But.... because I am a very impatient person, I am wondering if there is a way to make my own paste with tumbling grit? I tried making my own paste with just water and grit but as soon as I turned the dremel on it just flew off everywhere. What do I use as a binder? The diamond paste is oil based and creamy, Is there a way to make my own temporarily with silicon carbide grit while I am waiting for the real stuff?
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drjo
fully equipped rock polisher
Honduran Opal & DIY Nut
Member since May 2008
Posts: 1,581
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Post by drjo on Nov 22, 2010 4:42:24 GMT -5
Nothing wrong with a Dremel if you've got the time (some here are using wet/dry sandpaper ), is it a variable speed? Try a wax with a felt or cotton buff. Even the paste will fly off if spun too fast. You can make wheels from wood and Masonite or wrap a piece of chamois around an old bur too. I liked to clamp the Dremel to the bench and hold the stone (sometimes dopping it). Dr Joe .
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Post by johnjsgems on Nov 22, 2010 10:09:32 GMT -5
I knew an old timer that made polish laps for his facet machine by coating a wood disc with neutral shoe polish and sprinkling with diamond powder. Should work on hard felt bobs also. A lot of carvers use the wood skewers from the grocery store with diamond also. Not sure how well it would work with silicon carbide.
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Post by Hard Rock Cafe on Nov 22, 2010 14:45:31 GMT -5
I applaud your dedication, but if your time is worth anything to you, you might want to start saving your pennies for a true cabbing machine (grinder).
As Dr. Joe alluded to, you may be able to slow down. You can do the calculations to find the surface feet per minute on the face of your bobs or diamond bits to find the proper RPM setting. OR, you can just slow it down and see if you still get good results. It may be counter-intuitive, but Yorkshire Jack uses diamond bit drills in his Dremel at the slowest setting and gets good holes with longer tool life.
One last tip: I assume you're doing your grinding and sanding under water, or you should be. A flex shaft will allow you to do that without worrying about getting the motor wet.
Marie (superioragates) used to do Dremel cabs (don't know whether she still does), so she would be a good resource for you.
Hope that helps! Chuck
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Don
Cave Dweller
He wants you too, Malachi.
Member since December 2009
Posts: 2,616
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Post by Don on Nov 22, 2010 15:04:17 GMT -5
I think you could mix the grit with petroleum jelly and get good results. I used a dremel for carving fire agates and work the different grits over the stone with bits made from wooden dowels. I'm using all diamond paste though. Getting a perfectly smooth finish to the dome with this method would be challenging I think.
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Post by tntmom on Nov 22, 2010 21:52:08 GMT -5
Funny, I DID try petroleum jelly last night mixed with grit. Worked OK, but very messy, not something to do inside the house. Grit flew. Yes I have a multi pro variable rpm dremel. Using the slowest setting...I think it's 15k. I had a mess to clean up and then froze my hands off washing them outside in freezing weather because I had grit all over them. I called David Jade Carver today, ordered the paste (120, 220, 325, 600, 4000, 20000, 50000) and more felt burs. I already have 1200, 8000, 14000. He is charging me $4 a syringe. He is also sending me (for free) wooden dowels with something on them, that he said I should play around with. I got lost a little in the conversation but, apparently, wood and hand doing stones work well together. Will update when I receive my order. Nice guy, for such a small order, he spent 20 minutes asking questions to figure out what I needed. I was impressed with his help for me, a newbie!
Hopefully this works out!
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Post by jakesrocks on Nov 22, 2010 22:25:07 GMT -5
I have a friend that uses KY jelly instead of petroleum jelly. He swears by the stuff, and gets beautiful results.
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Post by johnjsgems on Nov 22, 2010 23:33:50 GMT -5
We're still talking about rocks, right?
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drjo
fully equipped rock polisher
Honduran Opal & DIY Nut
Member since May 2008
Posts: 1,581
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Post by drjo on Nov 23, 2010 7:50:56 GMT -5
I used a large clear (kinda) plastic tub set on it's side to work in and contain the over-spray. (At one point I put a clear plastic sheet on the opening and cut holes in the sides for my hands to go thru, but that was when I was using a slurry to polish with) Cleanable/reusable, a cardboard box works too, but lighting is difficult.
Dr Joe
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Post by jakesrocks on Nov 23, 2010 9:44:05 GMT -5
We're still talking about rocks, right? Yep. He works with Fairburns and TeePee's, and keeps a tube of KY on his work bench. Says it's a great lubricant for drilling rocks too. Don
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