I recommend drilling softer sedimentary rocks (sandstone, limestone, etc). When scouring the beach for rocks, these tend to be well rounded. Those that are not rounded are probably harder igneous or metamorphic rock and are likely to break apart while drilling or even break your drill bit.
Materials Needed:
- High speed rotary tool (I have a large, used drill press), but I've read that a dremel tool works well.
- A small (2mm diameter) and large (10mm) hollow, diamond-tipped coring bit.
- Plastic container to hold water so you can drill your stone under water (I use an old dog bowl). Drilling underwater cools off the bit and which will speed up your drilling and keep your stone from over heating.
- Adjustable wrench to hold your rock in place while drilling.
- Goggles
- Small sedimentary rocks
Directions:
1. Put on your goggles and choose which rock you'd like to drill.
2. Attach the small coring bit to your rotary tool.
3. Using your wrench, firmly hold the rock inside your container, just beneath the water. You are about to drill into the side of the rock (not into the face). This takes some practice. My rocks kept popping out at first, but I've since learned how to hold them steady.
4. Turn on the rotary tool and hold it perpendicular to the edge of the rock. Press firmly but gently. Do NOT rotate the hand holding the rock or else the rock will crack. The water will become cloudy, but that's fine. Continue to push firmly until the bit cannot drill any further.
5. Rotate the rock and drill a small hole into the opposite side.
6. Remove the small coring bit and insert the large coring bit into your rotary tool.
7. Now, using your wrench, hold the rock beneath the water, and slowly drill into the face of the rock until the coring bit pops through the other side.
8. Put the wrench aside. With the rotary tool still turned on, hold the rock steady in your hands while you press the coring bit firmly against the sides of your hollowed out rock to sand off any rough edges.
9. Rinse your rock in water, and that's it!
That's it! You may choose to throw your rocks into a tumbler, but I prefer the raw, rough look.
3. Using your wrench, firmly hold the rock inside your container, just beneath the water. You are about to drill into the side of the rock (not into the face). This takes some practice. My rocks kept popping out at first, but I've since learned how to hold them steady.
4. Turn on the rotary tool and hold it perpendicular to the edge of the rock. Press firmly but gently. Do NOT rotate the hand holding the rock or else the rock will crack. The water will become cloudy, but that's fine. Continue to push firmly until the bit cannot drill any further.
5. Rotate the rock and drill a small hole into the opposite side.
6. Remove the small coring bit and insert the large coring bit into your rotary tool.
7. Now, using your wrench, hold the rock beneath the water, and slowly drill into the face of the rock until the coring bit pops through the other side.
8. Put the wrench aside. With the rotary tool still turned on, hold the rock steady in your hands while you press the coring bit firmly against the sides of your hollowed out rock to sand off any rough edges.
9. Rinse your rock in water, and that's it!
That's it! You may choose to throw your rocks into a tumbler, but I prefer the raw, rough look.
































