Author Topic: Opals, Burrs and rotary tools  (Read 18747 times)


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Opals, Burrs and rotary tools
« on: October 25, 2013, 04:43:08 PM »
Hi All

Looking for some advice..

I have just started getting into lapidary recently, after years of picking up rocks.

Cabbing has been fun and I do enjoy it however, like many, I am fascinated by opals.

I have some boulder opal I am wanting to polish but the use of wheels is no really working for me.

I am looking for some advise on what sort of tools to get to start cleaning up some of the stones and removing the ironstone in the face of the stones i have. I have read some stuff, but thought here would be a good place to ask the questions i have.

I am looking at a dremel type tool, my queries are:
Is spending money on a dremel worth it? I saw a cheaper one at the local hardware, but wasnt sure of the quality.
Anything special i need to make sure about when purchasing a rotary tool for stone work?
Can they be used near water safely?
Do the out of the box attachments work ok to polish/clean stones or would I be better off buying some proper diamond burrs? What grits would you recommend?
Also, any brands of burr that are superior to others?

Other questions about how to actually do it come to mind also.. Do you submerge the stone and polish with the burr int he water? Or just wet the stone, then polish and wet again as required?
Any advise on how to keep the stone still in when using the tools on it?

Anyone have links to any good instructional resources on using the rotary tools and use on stones?

Thanks in advance for taking the time to read/reply  beers


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Re: Opals, Burrs and rotary tools
« Reply #1 on: October 25, 2013, 09:39:17 PM »
Best choice for you would be to find a local lapidary club that has members who work with Qld opal or opal in general and get their advice and help. :)
I try to take one day at a time, but sometimes several days attack me at once.


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Re: Opals, Burrs and rotary tools
« Reply #2 on: October 28, 2013, 11:49:07 AM »
I agree with JIMMYjerry, find a lapidary club. In the meantime I have a Dremel and a el cheapo which works much the same. The el cheapo is lighter and therefore in some cases easier to use but basically much the same.
The dremel is only of use for small pieces or areas, for larger stones you need bigger wheels or you end up with a lot of uneven dents impossible to polish.
In the meantime try glueing wet & dry to paddlepop sticks and use them. Use 240.320, 600,1200,2000 and finish with diamond grit on leather. I will warn you that you will probably spend all day doing what will take half an hour using lapidary club machines plus free advice.


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Re: Opals, Burrs and rotary tools
« Reply #3 on: October 28, 2013, 02:28:25 PM »
Thanks for the answers. I am in a lapidary club and have asked a few of the people about it, but havent been able to get much info. Most of the people there use wheels, and I used them also.

 I just have a few bits of opal with small bits of ironstone etc in them that I was hoping to remove without grinding off the actual opal.

Thought I might get some advise on tools and burrs in here if anyone uses them.


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Re: Opals, Burrs and rotary tools
« Reply #4 on: October 28, 2013, 03:59:07 PM »
Sounds like you want to free-form carve the boulder opal rather than cab it.
Might be an idea to ask among the club's carvers rather than the cabbers.



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Re: Opals, Burrs and rotary tools
« Reply #5 on: October 28, 2013, 05:13:37 PM »
I use a Dremel and it is a great starting device for carving. Get the hand piece extension as well then suspend the Dremel above your workstation and use the hand-piece to carve, that way the motor is kept well away from the water and when the hand piece dies from rust and rock muck you only have to replace it.

The grinding stones that come with the Dremel are too coarse to use on most stone, they also wear really quickly. Diamond burs are the way to go, Aussie Sapphire has great and very cheap starter kits of 20 or so burs that are great to start with while you work out which burs are most useful and you can then buy better quality if needed from there. Opal is soft on burs so they will last forever if used solely on opal.

Opal will shape pretty quick by hand with wet and dry as suggested. You can also cut up a 220 grit grinding wheel and make sanding sticks, these are really excellent and much faster than wet and dry strips.



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Re: Opals, Burrs and rotary tools
« Reply #6 on: October 18, 2022, 05:00:34 PM »
Hate to dredge up an old topic but I don't think I can find the info I'm after.

When it comes to using a dremel to carve opal, what sort of speed should I be setting it to?

Slightly different question to follow, can I use the same burrs/Nova points on sapphires that I would use on opals? Or should I have a different set for that for that?



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Re: Opals, Burrs and rotary tools
« Reply #7 on: October 18, 2022, 06:50:18 PM »
I would start on a lower speed until you get the hang of it. Less speed means slower to make a mistake and your remove less material. As you become more proficient you can then increase the speed. In regard to the burrs, I person ally wouldn't have thought it would make any difference, however I understand there are some clubs that keep certain ginding and sanding wheels for opal only. My thoughts are that if it's cleaned properly, it shouldn't make any difference but then I only facet sapphire and cabochon opal.
Common sense isn't exactly common


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Re: Opals, Burrs and rotary tools
« Reply #8 on: October 19, 2022, 10:01:18 AM »
Thanks Bucket, I was planning on starting slow for that exact reason. I guess I should have asked is there such a thing as "too fast"?

I guess the better bet would just be to buy a second set of burrs for the sapphires and keep them separate!


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Re: Opals, Burrs and rotary tools
« Reply #9 on: October 19, 2022, 03:15:57 PM »
My experience with rotary tools and burr-speed is a little counter-intuitive.

I usually let my Foredom handpiece rip, using it at high speed for many jobs. The slower you go, the greater the chance of the burr gripping suddenly, then doing a circumnavigation around your piece leaving a deep trench, whilst you stand there and watch helplessly like some sort of slow, dim-witted observer. I have worked mostly with precious metals, rather than stone carving, but the ideas are the same, lol.

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Re: Opals, Burrs and rotary tools
« Reply #10 on: October 19, 2022, 08:42:59 PM »
"is there such a thing as "too fast"
Might be for opal as heat will probably crack it easier than sapphire. Just a thought.
« Last Edit: October 29, 2022, 09:16:20 PM by RoughCreations »


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Re: Opals, Burrs and rotary tools
« Reply #11 on: October 29, 2022, 02:47:27 PM »
I watched this episode during the week. You might find it useful,,,


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