A friend of mine visited recently and commented on my bottle lamp. She absolutely loved it, so much so that she squealed with delight when I gave it to her. She refused at first until I insisted. She thought it was an expensive item I had bought from a shop. I explained that I made it at home which prompted her to ask me how I did it. I explained to her my process and then thought it would be a cool idea to give you an idea of what I did, so following on from her first question which was:
How do you cut a bottle at home? Stress is needed at the cut point. Score a line around the bottle using a glass cutter. Alternatively, use string soaked in lighter fuel and use direct fire to create a stress line. Expose the cut line to alternate hot and cold sources to make the glass expand and contract, causing it to break along the cut line.
We now know the basic physics behind making the scoreline and how to do it. Have a look below at a more detailed walk-through explaining exactly how it’s done.
How to Cut a Glass Bottle in Your Home
There are a few different ways you can do this. Depending on how many times you want to cut a bottle will most likely push you in the direction of one method or another. After looking at the main ways to do this you can decide which is most suitable for you.
Fire and String: If you are just looking to cut a single bottle then maybe this is the best way for you. It’s certainly the most cost-effective as you only need some string and some lighter fuel or acetone (nail polish remover contains acetone and is very flammable) and some thick heatproof gloves for safety.
First, soak the string in the acetone and then wrap it around the bottle so the string is tightly wound together and not spiraling down the bottle, you need just a single line. Tie the string to keep it in place. If you have any acetone on your hands stop now and wash your hands thoroughly.
Next, holding your bottle at one end while wearing gloves, near a bowl of water (for safety) light the string with a match or lighter. Keep the bottle at arm’s length as the flame can be quite high and intense. Once the string has burnt out you can remove the gloves and move to the next stage.
Boil a kettle and place it near your bowl of water which should be cold water. Safety glasses are also recommended for this stage as you will be trying to break the glass.
Holding the bottle from the base point the top down slightly. You want the water to run around the bottle but not onto your fingers as some of the water will be hot. Trickle the boiling water onto the burn line you made with the string making sure the line gets hot water onto it all the way around. You may need to rotate the bottle while you are holding it.
Next, dip the bottle into the cold water and hold for about 5 seconds. You could take an ice cube instead of the cold water bath and slowly rub it around the line. Repeat using the hot and cold water steps. You may need to repeat these steps a few times until the glass is stressed enough. When it is the end will just fall away from the end you are holding.
Glass Cutter: If you have a steady hand you can make a score line freehand with a regular glass cutter. It does need a really steady hand though as you need a perfect line that will match up when you score around the whole bottle.
If you are not confident in your steadiness then you can use a few simple tools to help. A few books or a block of wood can be used to keep the glass cutter steady.
Place the books or wood against the bottle and then hold the glass cutter with your hand resting on top you can get a much neater and reliable edge. If you use this method then note you need to try and score the bottle firmly but don’t use too much pressure or you may slip or score an uneven line.
When you are scoring the line note that you only need to go around the bottle once. Don’t try to go over the scoreline a second time. It’s not needed and will make your bottle more likely to break unevenly.
Glass Cutting Jig: My preferred method as you don’t need to try and be accurate. The jigs do that for you giving you a more reliable cutting experience every time.
There are three main jig types so you can choose a style which suits you best.
- The first is a handheld jig that clamps around the bottle. This is a good choice if you have limited working space. The jig can be screwed open to accommodate many different sizes too making it very versatile. You need to be extra careful when positioning this jig as if you are slightly off you can end up with an uneven score which will not work. The jig, once in place is rolled around the bottle until a score line has been achieved.
- The second is an upright jig. Using the top of the bottle this jig has a metal arm which you can adjust to the correct height with your cutter. Once you have selected this height you then hold the cutting arm against the bottle and slowly rotate the bottle. The base of the bottle remains on your worktop making it very stable.
- The third is a horizontal jig. This is by far the easiest but also the biggest. To select the cutting height you have an adjustable backstop for the bottle to rest against. Move this backstop to the desired height and and tighten the holding screw. Place the bottle on its side and with a gentle rolling motion rotate the bottle while ensuring the base remains against the backstop.
When you have made your score lines on your bottle you will need to follow the hot and cold water steps as mentioned above to stress the scoreline into breaking.
All of these jigs are very effective and much safer than using fire or freehand cutting. If you are unsure then have a look here at some cutting jigs to see them in more detail.
How to Cut a Glass Bottle Without Breaking It
The best way is to just go slowly. If you are using the hot and cold water method then don’t use too much of either at one time. Short periods of 5 seconds before switching works much better than 10 or 20 seconds. You want the glass to expand and contract gently along the scoreline but often as well as this will provide more stress in the right way rather than trying to hit it with too much heat or cold.
For a more in-depth guide check out this article:
