Best way to drill a hole in a cowry and conical shell?

If you can’t do what you want to do with a Dremel and one of it’s many magical attachments, then I am already out of ideas. Sorry… but, have you tried using the Dremel on a very low speed? .

It’s not that I can’t make the hole. It’s that I’m not sure where to put it. In these cowries and cone shells, the geometry is such that you cannot see the other side of where you drill, and what you are drilling into is not hollow either. I don’t want to crack the shells. I’m not sure if I need to hollow out the shell first before drilling, or if I can just go for it. I’m pretty sure I at least need to do it submerged in water (I got stress cracks on the first shell I did – which was more like an ‘opihi where I could see both sides of the shell clearly), but I’m not sure if this is enough or if I need to start with a tiny needle-sized hole and work up from there or take some other mitigating measure I don’t know about. I only have one bit, and it isn’t needle sized…but I may be able to hunt down a smaller one.

Here is a photo of a cowrie and one of the types of cone shells I have for reference.

So basically, I know the dremel will make a hole in these shells wherever I want it. I’m just not sure how to make the hole without cracking the shells into bits. And I’m not sure where the best place to put the hole is in each case.

The stress cracks might be from drilling at too high a speed, that’s what I was thinking.

I am pretty sure that was at least part of it, as I had it about 10 steps from the max speed. I also didn’t have it submerged in water, and it did heat up quite a bit. It also may have been too large of a hole to start out with…but perhaps going at a slower speed would sort of ‘burrow’ through so that the tip has a chance to make a smaller hole before the whole diameter of the shaft goes through…did that make sense, lol? Anyway, any thoughts on where I should put the holes on these shells though?

You’re trying to make beads/jewelry with them? Are you trying to drill from the inside of the shell or the outside? How are you stabilizing, holding the shell steady as you drill?

Yes :)

I think it would be easier to drill from the outside. I did the first one from the outside.

The first one I did I just held it with one hand while drilling with the other, and took breaks when it started to heat up. Got a clean hole… and the one hairline crack.

I would fashion something to hold the shell in place, you can make something with scrap wood if you don’t have a vise, and if you do have a vise you can fashion something out of scrap wood to put between the metal that won’t harm, crush or scratch the shell. It would probably really help if the shell was immobilized. I don’t suppose you have the drill press stand for your Dremel? That would be helpful too.

Use a vice to hold the shell and drill with a diamond bit at a lower speed.Don’t drill too close to the edge or at a spot that looks too thin.