As you learn how to cut a wine bottle and practice this combination of science and craft, it is important to understand the differences between cutting glass that is flat or rectangular compared to cutting round surfaces such as wine bottles.
Even cutting a curve or a circular shape on a flat surface is relatively easy in comparison. Scribing or scratching a good line on a flat surface, then lightly tapping on the opposite side is a standard way of making a flat cut on glass.
However, when trying to cut bottles in this traditional way it is more difficult to scribe the good line needed. One thing that makes it harder is rotating the bottle smoothly while holding the cutter. Not only that, but bottle glass can sometimes be thicker one place than another.
Of course, using the tapping method means getting inside the bottle somehow. With all of this in mind, the traditional way is generally still considered the correct way. A few well-thought-out preparations can certainly make the task go more smoothly.
Use a standard glass-cutting tool
A standard glass-cutting tool like the one that would be used for windows will work well, if used in combination with a couple of other items. There are a couple of ways to hold and turn the bottle. One is with a specially designed piece of equipment that holds the bottle gently but firmly at both ends and allows the bottle to be rotated manually.
Of course the neck opening must not be obstructed so the tapping tool can be inserted. Another popular bottle holder can be constructed with two straight, smooth pieces of wood formed into a trough that has a “V” shape. The bottle can be turned by hand, but make sure the wood is smooth and straight.
Tapping on the side of the glass opposite the cut is accomplished by inserting a metal rod that is bent slightly on the end to provide a tapping surface. Experimenting with different weights should produce a tapping tool that is comfortable and provides enough tapping force to do the trick.
Experienced bottle cutters will also have a piece of wood, or even a rubber stopper, on the rod to keep it from slipping all the way into the bottle. Some steady-handed craftsmen have perfected the art of cutting bottles in this “freehand” style.
How To Cut A Wine Bottle?...use a string.
While this can be done with excellent results, there are other ways that may help produce the smooth cuts necessary. One suggestion for how to cut a wine bottle that comes up in discussions is the low-voltage wire method.
This requires some patience and a bit of knowledge on how to construct the proper apparatus. In general, the most successful methods employ an auto battery as a voltage source.
A length of high-quality wire connected to this source must be wrapped around the bottle. Then the pressure must be applied around the wire at the same time to avoid unwanted cracking. This is a more complicated method than some others, but could be worth a try. It is strongly suggested that anyone using this method take plenty of time to prepare then practice on several bottles before trying to produce a finished product.
Other bottle cutting methods
Two other methods that have been used with some success are a torch with sufficiently low heat and the use of a saw that is capable of making a fine cut. With heating methods and with mechanical methods such as these, it is absolutely crucial that the person doing the cutting be prepared for minor problems with cracking, breaking and even unwanted melting.
Many people who have tried these “advanced” methods have ventured back to the traditional scribe, turn and tap plan. Good luck!