Trying to cut a glass bottle with a diamond tipped glass cutter, I failed; Any practicable suggestions?

Question

Some glass bottles when cut to the required size, can
be very good utility items.

Answer 1

To cut glass you first score the glass (which you have done), then "run" the score out. When you cut glass, you are basically breaking the glass, and the score "tells" the glass where to break. The break fill follow a good score.

When you score the glass, you are changing the molecular structure (or alignment?) of the glass along the score. However, the score will "heal" over a short time. The glass will go back to it's original molecular structure and all you have is a scratch that is of no use. So you will need a new score line.

The glass bottle cutting kits came with a cutter attached to a stand or jig for scoring along with a tool for running the score. It was a small round weight at the end of a long thin handle that could fit inside the bottle, like a little hammer with a 1/2" diameter head. This is because you have to tap the score from the other surface of the glass.

So, make a new score, at least 3/8" lower than your old one, and find or make a tool that you can use to tap the score from the inside of the bottle (right after you score it). You can try to heat the score, but it's unpredictable.

Answer 2

If your just trying to take the top off it can be done by heating a 'line' all the way around the bottle then touching a cold peice of wire on the same part (the sharp contrast in temperature will cause the glass to 'split' all the way round the heated line) The edges wil still be very sharp so if you have a glass grinder i would suggest taking these edges off straight away after. You'll find it very tricky to get a smooth clean cut with a diamond tip cutter and might be better off using one of them hand held engraving tools if your detirmind to do it that way, but would as other answer suggests pack the bottle with sand 1st to give the bottle more support.

Answer 3

You can find bottle cutters at craft stores. They were very popular a few years ago.

Answer 4

Fill it tight with sand first then cut it