Carving into a rock or stone is interesting, it has a sense of permanence. A few years ago I read an article in Make Magazine on how to carve a stone bowl and it has been lurking in my mind since then. It was much easier than I thought and I’m sure I’ll make more of them, and larger ones.
What I Used
Materials
- A nice stone
Tools
- Angle grinder
- Diamond cutting disc
- Diamond grinding cup
- Hammer
- Chisel
- Marker pen
Protection
- Hearing protection
- Eye protection
- Dust protection
Find a Nice Stone
After a bit of looking around in the yard, I found a stone that I thought would be suitable bowl material, that means not too small and not to large, and most likely round.
Remember that it is more or less impossible to carve out a bowl smaller than the diameter of your diamond cutting wheel. So if you got a 125mm diamond blade it has to be that plus the thickness. Mine were around 200mm.
Splitting the Stone
First, I found a flat surface on the stone where it stood steady and balanced.
Using a marker pen I drew a line around the stone to use as a guide line when cutting. A tip here would be to keep the marker stationary while turning the stone on a lazy susan or something like it, that way you will get nice straight line around it.
While keeping the stone steady and secure (I really don’t want to bend and possibly snap the angle grinder blade while spinning) I cut all around it as deep as the blade went.
Hollowing the Stone
The easiest way to hollow it out that I’ve found is by cutting a grid with the angle grinder. I cut as deep as the disc went.
Keeping everything stable is always important when working with an angle grinder. As mentioned before, I like to avoid snapping a blade, at least while it´s spinning.
So the method I used was; cut a grid, chisel it out, cut a new grid, chisel it out and so on until I was satisfied with the depth.
Grinding
So, now it’s time to grind the lines and uneven surface left by the grid cuts. To do this, I attached the diamond grinding cup. Note: the diameter of the grinding cup must be equal or smaller than the bowl.
There seems to be quite a few styles of the diamond grinding cups, some deep, some convex, all with different abrasive patterns. I’m not sure how this affects the surface, so if anyone reading this has a good explanation, please comment.
It looked pretty disappointing until I cleaned it off with some water.
Polishing?
I didn’t polish my stone bowl, but I might buy a set of diamond abrasive pads to try. There seems to be some cheap ones on Aliexpress as well on Amazon. I might try this on my next stone project. Maybe a birdbath?
Well, the cat is happy.
