5 Easy Ways to Cut Glass Without a Glass Cutter

A glass cutter is a handy tool you can acquire for as little as $5 on Amazon, but what can you do if you need to cut a mirror or piece of window glass or do a craft project when you don’t have one on hand? Or you don’t want to spend the money on something you may never need again? Whether you are thrifty, can’t get out, or don’t want to wait a couple of days to get the right tool online, there are several tools you may already have on hand to do the job.

While the supplies for cutting glass vary by technique, you should always undertake the process wearing safety glasses or goggles and work gloves. If the glass does not break cleanly or survive the process, shards of broken glass can be a serious hazard.

How To Cut Glass Without A Cutter – The Best Way

A glass cutting tool scores the glass, so this can be done with several other implements.

Diamond or carbide scribe

A scribe, a pencil with a sharp top, can score glass. Carbide tips ($10) offer sharp, precise cuts, while diamond-tipped ($20) ones last longer. Even a steel file or utility knife you may have on hand can do the job.

1. Put down 4 or 5 sheets of newspaper on a tabletop or floor to offer padding. The flat surface is needed for support.
2. Clean the glass and wipe it with a microfiber cloth for a precise cut that does not dull the cutting tool.
3. Precisely measure the mirror or glass and determine the cut line. Mark the cutline in 3 or 4 places with a permanent marker. For glass being cut to fit a frame, make it 2–4 millimeters (0.079–0.157 in) smaller than the frame’s interior to ensure a perfect fit.
4. Squirt a few drops of glass cutting oil along and rub it evenly across the glass to produce a more even cut.
5. Score the mirror with your scribe or file by pressing hard on the tool and pulling it across the line you have marked. Once you have started scoring, complete the cut in once continuous. If you are using a steel file, you may need to go over the line 2 or 3 times.
6. Center a dowel longer than the length of the cut under the scoreline.
7. Evenly press down the glass on either side of the dowl to snap it. If the glass does not respond to pressure, try pressing on it at different places along the line.
8. Sand the edge of the glass with 200 grit sandpaper, as the edges will be rough and sharp.

 

Other Techniques For Cutting Glass

Using a scribe closely replicates an actual glass cutter, but there are other ways to approach the problem.

• Angle grinder with a diamond blade

Useful for cutting bottles or even flat glass, an angle cutter can do the job. As with other cutters, the angle grinder scores the glass and can cut through a bottle even when a lower quality blade is used. (A thin diamond or tile cutting blade is best.) Doing it takes a while, uses costly blades ($40+), and may spray glass shrapnel and silica dust around during the process. The cut will require some sanding to smooth it out.

There are two other cautions when using an angle grinder. First, the dust the process produces is a health risk, so a dust mask is essential. Also, this process should not be used for tempered glass, as it will shatter. Despite the cautions, some users swear by this method as it cuts through the glass without heat and cold dip the glass.

• String

This technique is more appropriate for small pieces of glass or bottles, but a string lit on fire can do the job of cutting.

1. Tie a string tightly around the glass where you need to cut it.
2. Set the string on fire.
3. Plunge the bottle into a bucket of hot water.
4. When submerged, hit the glass below where you want it cut. The water will soften the blow and vibrations from the hit.
5. The glass will break along the string line.

A variation on this involves soaking the string (preferably natural fiber twine) in lighter fluid, acetone, or alcohol) before tying it around the bottle. When you set the twine on fire, the lit string may make the glass change color, which indicates it is ready for the next step. When you quench it in a bucket of water, you will hear a snapping sound when the glass breaks. Thicker glass requires more time before submersion.

• Wire

Similar to methods using string, the wire method requires submerging the glass in water after cutting.

1. Score the desired cutting line on the glass.
2. Shape the ends of a long piece of wire into loops and put wood through them to make handles.
3. Heat the wire until it is red hot and place it along the scored line.
4. Submerge the glass into a bucket of cold water, which will cut the glass.

• Scissors

While cutting glass with scissors sound unusual, this technique works well for small pieces of flat glass that you want to cut into shapes. The water lubricates the glass and creates external pressure to prevent cracking.

1. Mark a cutting line on the glass.
2. Submerge the glass in a tray of water and cut along the line.
3. Clean up the cut line with a blowtorch or whetstone.

 

Choosing Your Glass Cutter

Glass cutters are specifically designed to make clean cuts every time without wasting material. An easy-to-use bottle cutter or flat glass cutter costs less than $20 – something to think about if you need to cut lots of bottles for crafts or gifts. However, some of the techniques listed above will do the job for a quick cut or a craft project on a budget with old wine bottles.