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Glass cutting for the nervous!

A short guide to cutting glass safely
by Glassprimitif

Cutting glass is my favorite part of glass art. It has something to do with the sounds - the hiss of the cutter and the snapping of glass. When I first started stained glass classes the teacher told me “you will only ever make one mistake when cutting glass and then your glass cutting skills will always be perfect”. He lied about that but it sure boosted my confidence

Tools of the trade

Here are the tools you will need for successful glass cutting. From left to right: dustpan and brush to sweep up glass shards, a ruler for accurate measuring, a permanent black marker for drawing on glass (use gold, silver or white markers on dark glass), a glass cutter (this is a Toyo original Supercutter), grozing pliers for snapping and nibbling glass shapes, cut running pliers (blue) for snapping larger pieces of glass and a self healing mat with a grid.

About glass cutters
Which glass cutter should you buy? Well, avoid buying a cheap cutter from the local hardware store (it will end in tears). Instead purchase a quality cutter from a stained glass supplier as you get what you pay for. There are several types of cutter including oil filled, spring headed, pistol grip and the basic, old fashioned cutter without oil. Modern cutters have a tungsten carbide wheel that will score glass easily with the help of a drop of oil. So, if you buy an oil filled cutter don’t forget to buy the oil too! Cutters that don’t have an oil reservoir still need a drop of oil on the glass to assist the wheel in gliding along the surface. Pistol grip cutters are shaped to make holding the cutter easier and may be better if you have a weak wrist or joint problems. I use a Toyo Super Cutter that has a sprung head and an acrylic barrel for the oil. Each time I press the cutter down onto the glass to begin to score, a drop of oil is released onto the glass to lubricate the wheel. Never let your cutter work without oil and keep the head clean. Remember – your cutter is your best friend so treat it with respect.

Scoring your first piece of glass
You will need to practice cutting glass at first until you gain your glass cutting confidence so start off with scrap glass such as picture glass. For your first cut place the glass flat onto your work surface. If your glass has a bumpy surface (such as a hand rolled glass) place it smooth side up.

Now practice holding your cutter. The cutting head should be almost, but not quite, vertical as shown here. Grip the cutter between your thumb and forefinger – at first it will feel awkward but comfort comes with confidence. All glass is cut from A to B. By that I mean, you can cut glass in a gentle, wavy line but you can’t cut it in a zig zag pattern. To cut a straight line, use a ruler and permanent marker to give you a guide line.

You are ready to cut glass. Your cutter is going to make a steady progress from A to B, scoring the glass evenly without stopping. Hold the cutter comfortably and place it on your glass, slightly in from the edge. Press down firmly. If your cutter has a sprung head this will release a drop of oil onto the glass. If you don’t have an oil filled cutter place a dab of oil on the glass in front of the cutting wheel.

Guide your cutter across the glass to make the score line. You should hear a satisfying hiss as the cutter makes its journey. Don’t cut too quickly and don’t panic – your cutter is doing its job. If you are cutting across a large piece of glass you may want to hold the top of the cutter with your other hand as shown here. Try not to rock the cutter from side to side as you move – steady as you go.

Breaking the glass
Once you have scored the glass you only have a few minutes to break it or the score line will heal again. There are several ways you can do this. Take the piece of glass in both hands and snap it firmly by pulling each side down. Make sure you are wearing cotton gloves to avoid cutting your hands. If the glass doesn’t snap straight away you can tap the underside of the score line with the end of the cutter and then break the glass.

This will work with average size pieces of glass but avoid doing this with a large sheet as it may fall and cut your wrists. (Ouch)! For straight cuts and large pieces, cut running pliers are ideal. Place the glass between the pliers and press down – your glass will snap perfectly

Cutting shapes and small pieces
Lots of different shapes can be cut in glass such as rectangles, squares, ovals, circles, triangles, amoeba-like shapes, leaves and hearts. Shapes with curves, such a circles and hearts will require grinding to define the shape. I find hearts the most challenging and I enjoy cutting and grinding curvy shapes. I’m going to take you through cutting a basic fish shape that has sharp edges and curved lines.

Top tips for glass cutting

• Buy a quality glass cutter and don’t forget the cutter oil too.
• Practice scoring with your glass cutter on waste glass until you feel confident.
• Cut on the smooth side of the glass if possible, but avoid practicing on opaque glass – you don’t hear the “hiss” when cutting opaque glass so you can’t judge if you have scored it correctly.
• Don’t stop moving the cutter when scoring your glass as you can’t start again halfway across. Remember – glass cuts from A to B.
• If you make a poor score line you cannot cut it again over the same score line.
• Stand up to score glass – you will need to be above the glass and use your body weight to lean down on the cutter.

A little something about Health and Safety Glass is dangerous stuff – you might cut yourself badly or get a shard in your eye or ingest powdered glass. This is why glass must be treated with a healthy respect by employing good studio practice.

A little something about Health and Safety
Glass is dangerous stuff – you might cut yourself badly or get a shard in your eye or ingest powdered glass. This is why glass must be treated with a healthy respect by employing good studio practice.

• Always wear shoes, not bare feet or open sandals, in your studio.
• Don’t leave large pieces of glass lying around, take time to put glass away when not in use.
• Always wear cotton gloves when picking up large sheets of glass to avoid slicing through the palms of your hands.
• Never carry sheets of glass flat. All larger pieces should be held upright to avoid pressure in the centre of the glass.
• After cutting each piece of glass brush your work surface with a brush and dustpan. This will prevent small shards sticking in your hand as you cut the next piece.
• Don’t eat or drink when cutting or grinding glass as ingesting powdered glass is very dangerous.
• Keep all pets and small, annoying children away from your work area and glass (or ban them altogether).
• Have a box of Bandaids handy. It’s really irritating when blood drips onto your glass.

No matter how vigilant you are you will still occasionally pick up small nicks and cuts in your hands but, if you can avoid severing a major artery, then cutting glass is quite safe!

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