I've been trying my hand at etching glass with my Dremel 4000 & a Flex Shaft. I've been experimenting with different diamond bits and speeds but my edges always come out chipped.

I use a water drip system I sort of invented to keep the dust down and to keep the bits and glass cool.

The glass I'm practicing on is from a candle, so it's pretty thick.

If anyone could give me some tips, I'd really appreciate it. It would also be really helpful if anyone could share links to some good bits. Searching Amazon gives me hundreds of results and they mostly seem to be the same thing.

Thanks in advance!

some of the edges are just me being new at this, but you can clearly see actual chips in the glass

  • Welcome to the community, Brandinomite! Can you provide images of the drill bit you are using. There are tons of different bits to use on a Dremel. Glass drill bits, diamond drill bits, or rotary bits. Depending on what you are trying to achieve.
    – Lyssagal
    Commented Mar 3, 2021 at 18:57

2 Answers 2


It's hard to diagnose without seeing the bit you used, but here are my ideas:


The line in the center of your image has only one chipped edge on one side. That implies that the problem either arises at the side where the tool starts touching the glass or leaves the glass.

If you turn the glass (or the tool) so that the rotation of the bit is parallel to the line you're etching, the chipping might still occur, but it won't be visible because it'll be part of the line.


The bit you're using might be too coarse for glass. Of course the bit needs some grain to be able to etch glass at all, which would be visible as bumps under the microscope. When one such bump touches the glass, it breaks tiny parts of it away. High grain bits have a lot of tiny bumps, which break the glass away evenly like a chain saw would cut a block of ice evenly. With lower grain these bumps get bigger and fewer, chipping away chunks of glass like an ice pick would chip a block of ice.

Uneven rotation

I've made the unfortunate experience that bits sometimes won't be centered properly in the collet. You can have the same effect if the shaft of the bit is slightly bent or if the stone of the tool (if it has one) isn't centered. As a result, instead of a constant grinding you get a tool that jumps over the surface like a miniature jackhammer.

  • An additional thought on orientation: hold the rotary tool not only parallel with the line, but so that the rotation has the bit enter the line at the outer edge of the line. The chipping is likely from abrasive particles on the bit catching the glass on the way out. If the bit rotates in the direction that it exits on the inside of the line, most of the chipping should be hidden as part of the line. It may also help to do the grinding completely under water, like in a small basin. Use a flexible shaft to avoid getting water inside the tool, and blow out the shaft when done.
    – fixer1234
    Commented Mar 10, 2021 at 22:21

Most common would be a rotary bit. This one would be specifically for glass carving: Amazon link
The bottom row would be the fine detail tips, would be beneficial to wanting to carve out small detail.

Brand wise, you really can't go wrong with a rotary bit. I have been in the tool industry for about five years. Yes, you can get really high quality rotary bits. They will last a long time. Dremel would be a medium range quality of rotary bit. Which would be recommended to a hobbyist, or even a professional.

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