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Gadgets, Gizmos, and Dohickeys => Cutting, Grinding, Polishing => Topic started by: nwbeachrocker on January 21, 2017, 11:52:28 AM

Title: Drilling Stone
Post by: nwbeachrocker on January 21, 2017, 11:52:28 AM
Hello,
I'm looking to drill some holes in agate and other rock.  I have seen some examples of cabs on this site with some clean holes, nice beveled edge and all.  I recall seeing a few that Gergis had done.  Any recommendations on the best type/brand/source for drill bits for this?  I've been using some cheap harbor freight diamond coated bits, but would like to invest in something decent.  Cheers
Title: Re: Drilling Stone
Post by: lithicbeads on January 21, 2017, 04:55:18 PM
Any sintered bit works well if well lubricated and a light touch is used.
Title: Re: Drilling Stone
Post by: peruano on January 21, 2017, 05:35:45 PM
The person who said any sintered bit knows his stuff, so there's your answer.  I believe my bits always come from lasco, and while I have broken my share of stones in the drilling process, its a matter of a light touch, patience, a new bit when appropriate, and practice.  I use a Dremel drill press attachment but many small lapidary drills will work as well.  There is a tapered bit that can be used to flare the hole superficially,.   And of course don't allow that stone to slip in the process.  I nest mine on a layer of thick cardboard that when soaked with water does allow the stone to nestle securely, and provides a bit of gap so I don't drill through to the bottom of the container holding the water coolant.  Drill away with confidence, but practice on some slabs before you do your best and final produced cab. 
Title: Re: Drilling Stone
Post by: gemfeller on January 21, 2017, 06:14:08 PM
Maybe I'm behind the times but all my diamond bits from Lasco are plated.  I don't think they supply sintered bits unless it's something new.

Several companies offer sintered tools including Badger, Mountain Mist, Kingsley North, Diamond Pacific, Gesswein, etc.  I'm not sure how cost-effective they are compared to the cheap Chinese plated bits.  If you're careful and aren't doing production work you can make quite a few holes with the disposable cheap ones.
Title: Re: Drilling Stone
Post by: nwbeachrocker on January 21, 2017, 06:35:49 PM
Great info, thanks.  Are we talking about solid shank or core drills here?
Title: Re: Drilling Stone
Post by: gemfeller on January 21, 2017, 06:54:31 PM
My reply concerned solid bits,  except for Badger (both).  Just Google "sintered diamond core drill bits" and you'll get lots of hits.