Fossiilized Coral Necklace Tutorial

[Taogem]

Got my vice in the mail today. 

The disappointing part was thinking the small town I live in would have some diamond bits 

Being anxious to get started, I settled reluctantly upon trying some cobalt bits.

I wanted each and every stone to have identical angle for the drilled holes. So I made a sort of jig so that each and every stone would be drilled at the same angle.





Clamped everything down and submerged the vice and stone under water.



Right away, it was apparent that there was no way I was going to be able to get a drill hole started at the angle the stone was set at.

So I brought the clamp up to where the drilling surface on the stone would be 90 deg to the drill bit.



Guess what?

The cobalt bit is not even going to work  :

So I am off to order something up online.... And back to more waiting

[Lavenderfish]

Taogem,

If you haven't already ordered from somewhere and want to use the plated type of bits, Crystalite Triple Ripple diamond drill bits have  a good rep. You can find them at various lapidary supply houses like Kingsley North and Indian Jeweler Supply. IJS will probly have the best prices. I've gotten plenty of bits for drilling and carving from Daniel Lopacki too, has more bur shapes than you can shake a stick at (www.lopacki.com).

If you're certain you'll drill bzillions of holes then you may want to consider using sintered drills. In that case, check out www.mtmist.org They aren't cheap but would last a long time compared to plated.

I mainly drill holes that are 3-10mm, so buy pretty decent diamond core drills from an ebay fellow in Hong Kong (lau*** is his seller name) They're pretty darned good for plated and the prices are good. I also use his diamond twist drill bits for smaller holes after I get the hole started with a round bur. They generally arrive within a week or less too.

Those are just some suggestions & alternatives to help you get started looking. Hopefully helpful and not just making your head spin! 

[Taogem]

Just about right away my head started spinning   

Thanks for all the info and links Carol.

I thought might just start out with a set like this. They are diamond coating on nickel plating.

Get the feel of them and then order up a few similar sized individual bits. Just about everything will be for stringing necklaces and bracelets.

[Taogem]

Well, I sure am open to suggestions.

Not entirely sure that the fossil coral might just be too hard?

Broke two bits trying patiently to drill the first cab.

The pic is out of focus, but you can see the condition of the third bit compared to the point of a new one.

I hardly used any pressure.

Crappy bits, wrong kind of bits???  They are a diamond coated on nickel plating.



Not entirely sure what to do now.

I did get the third bit to work on some softer material ok, but only got half way through the first fossil coral cab.

[Lavenderfish]

Looks like those burs are from one of those 20 or 30 assorted bur sets? If so, yah, those aren't the right ones you need to drill with, they're better suited for carving. Bet'n when the bur ran out of diamond on the end and you kept pushing, bur heated up and plating peeled completely off? Been there!

In the photo I attached, these are some of the different drills I use: Round bur, 0.75 mm drill bit, twist drill bits, core drill (it's 3mm, puts into perspective how small these are)

The small round bur (100-ish grit) is used just to start the hole so the drill bit won't skate around when you start.

Switch next to the first drill bit which is 0.75 mm.  For fossil coral if it's really hard stuff, and I think it is, you might be better to use a 1-1.5mm drill bit so it's a little sturdier.  Since you're using a vise, you can drill all the way thru the stone until you come out the other side. Just be careful when you get close to going completely thru, you'll get a little blow out at the exit point, but will be such a small hole that you'll drill that away later when you countersink as the last step.  Note; I only bear down just a hair for a couple seconds with the bit and flush with water each time afterwards. So you drill, lift out, flush, repeat over & over & over.....

Now you can enlarge the channel you have with the next larger diameter drill bit and keep repeating that process until your hole is as big as you want it.

Another option is to use core drills. The smallest one you can get (that I know of anyway) is generally 3mm and I love using those. When drilling holes into beads that will be lined with siver tubing or will be strung onto a cord, I always use core drills. With these, you can just use whatever diameter of core will cut the final size of hole you need and there's no monkeying around switching bits, etc.

If eventually you have tons & tons of holes to drill and you just don't wanna mess with it or spend the time to do it, I can give you the name of a pro lapidary who does ultrasonic drilling and will do an excellent job for you. :-)

Now your head's gotta be spinning like Linda Blair.....LOL

[Taogem]

That second bit looks looks to have the same flat head like the one I posted a pic of.

If so, and if it is diamond like the ones I used, then wonder what will keep it from wearing the diamond off the end as I did?

I did make a starter hole with a pointed/tapered bit. Then got about a 2 mm bit to start a-ok. It just would not last.

Yours are all diamond as well, right?

Is it expensive to have something sent in to be sonic drilled?

Will they do just a few, or do we have to send several at a time?

Thanks for the help Carol 

[Lavenderfish]

Hard to say re: reasons for diamonds wearing away or not cutting after a short time. Keeping a bit from heating up too much and constantly flushing the swarf away are about all you can do to help it last longer. Maybe too, that hard-as-nails agate is gonna require more than one bit to make it all the way thru the bead. Sintered drill bits would hold up better for those tough jobs like agate & jasper like you will probably want to do.

Re: ultrasonic drilling, Jason Penn is who I'd recommend for that and his number is 877-988-2737. He can do a few if you want and the price goes down if you have a larger number of pieces to do. You'll like Jason, he's a nice guy & a very good lapidary. Can't remember what the price was last time I asked him but don't think it was that much.

[Taogem]

i found a ultrasonic drilling unit. At 3800.00 will have to be added to the wish list.

I would like to do a few more drilled stones for necklaces and bracelets. These bits I have will probably be ok for drilling from front to back on a flat stone.

These side to side holes are a different story.

Will call Jason first thing tomorrow. Sure would like to finish these.

Wonder if I will be able to send him a finished cab instead of these preforms?

Thank you for the number Carol 

[Taogem]

I went ahead and tried the number today even though it is Sunday.

Jason answered. Very pleasant and helpful.

After talking with him it became apparent that in fact fossilized coral and the like is very difficult to drill. Especially when getting up to half inch long holes.

He explained that the sonic drilling is really the easiest and most practical drilling method for these harder and long hole projects.

A little pricey at .40 per mm. Works out to about 4.00 a cab. The bracelet stones were going to be double drilled so could be strung.

Thinking will just send in the necklace pieces and finish up the bracelet so those pieces will end up being used in a series of bezel settings.

Will not be able to use the center piece that had picked out for the necklace. Can't even sonic drill the distance. So sending off a narrower preform to be drilled and will figure out a design when returned.

[Lavenderfish]

Tao, Been meaning to ask you if you you ever got all the holes drilled for your necklace pieces either by hand or by sonic method?  How did it turn out?

[Taogem]

As I hang my head down low.......

No.

I did not send them off to be drilled with the sonic equipment.

I am torn between thinking that I would get the 5.00 it costs for each cab to be drilled back out of the price I would like to see the piece priced at.

I sorta had planned on pricing the finished necklace at about 30.00.

That would more than double if I send them off to be sonic drilled.

So....., I am just going to finish these stones so they can be used in linked bezel type settings.

Even though I had no luck with drilling this very hard Fossil Coral, I don't foresee the same problem with a lot of other much softer minerals. I have tried on a few without any problems.

To help me overcome feelings of defeat on this particular set  , will start another thread or pick up here with a different mineral "drilled" necklace or bracelet set.

[Taogem]

After Carol suggested to try drilling through some Jaspers earlier today, I said would give the bits a second chance.

Guess what?

Drilled right on through a couple of quarter inch thick Jaspers without a problem.

Now my motivation to start up with another necklace or bracelet set has returned. 

I noticed as well that the tip / flat end of the bit does not show any wear like in the pics above from tryong to drill the fossilized mineral.

Most excellent!!

[Lavenderfish]

Woo Hoo!!!! I'm so Happy  to see that cloud of discouragement over your head go poof! Will look forward to Plan B

[Taogem]

Ok, another successful step.

Since had to work with softer mineral in order to even think about drilling sideways or lengthwise, I decided to pick up where I left off with the Fossil Coral and go with Malachite.

So here I am ready to start in on some nice drilled preforms.  I was able to cut the cabs to 24 mm wide. The length of the coated part of the drill bit was about 13 mm. So it worked out ok drilling from both sides of each preform.

[Taogem]

Well, I have many more drilling experiences to go through before making claim to job well done !  :

Realized that the holes were not drilled exactly straight on most of these. Two of them were ok and managed to salvage a couple more by reshaping the cabs.

Don't even ask me what the brass beads and cheap chain are about !    Was just playing around with my few and proud drilled cabs 

Back to the drawing board...