Cutting a mirror comes into play when you're making crafts or if you need to cut mirror tiles or a wall mirror. The two-part process of cutting a mirror—first score and then break—requires just a few special, inexpensive tools. Cutting a mirror is an easy process that takes just a few minutes.
Before You Begin
Before cutting, the mirror must be scored. Scoring the mirror requires a glass cutter. A glass cutter is a hand-held tool with a small carbide wheel at the end that rolls over the mirror to score it.
Glass cutter grips vary. Basic models have a pencil-style grip with a ball at the top. Other glass cutters have pistol or T-shaped grips that are easier to hold.
Cutting the mirror requires running pliers, but only for short straight cuts or for gentle freehand curves. Running pliers have a curved head that clamps both sides of the score line to snap the mirror apart.
For long straight cuts of more than 18 to 24 inches, it's best to separate the mirror across a long, thin item placed under the mirror. A straightedge, thin board, or the edge of the table will work for this.
When cutting a mirror, glass may fly. Wear protective glasses with side shields. Leather gloves are recommended for protecting your hands from cuts.
Equipment / Tools
- 1 wheel-style glass cutter
- 1 glass-cutting oil
- 1 running pliers
- 1 metal straightedge
- 1 pair leather work gloves
- 1 mirror
- 1 can glass cleaner
- 1 roll painter's tape or duct tape
- 1 roll paper towels
Prepare the Work Area
The mirror needs to be on a completely rigid work surface such as a sheet of plywood placed on a table or on the ground. Thoroughly clean the work surface. Add a sheet of fabric such as a thin blanket to the work surface. While not absolutely necessary, the fabric helps even out any surface imperfections.
Use the glass cleaner and paper towels to clean both sides of the mirror. Place the mirror on the work surface with the reflective side up.
Mark the Cut Line
Mark the two ends of the intended cut line. Set the straightedge on or near the line. Note that the cutting wheel on glass cutters is centered at the end of the tool. So, there will be an offset of between 1/16-inch to 1/8-inch. Adjust the straightedge accordingly.
Oil the Glass Cutter
Add a drop or two of cutting oil to the cutting wheel. Some glass cutters have an attached chamber that can be filled with cutting oil, and these tools will self-lubricate.
Score the Mirror
Hold the glass cutter with the cutting wheel on the mirror. Press firmly. In a single stroke, score the mirror from end to end. You will hear a distinctive grating sound if the mirror is being scored properly.
To make a gently curving freehand score without the straightedge, score from one end to the other end in the same manner. For the mirror to separate on the score mark, aim for a curve that deviates from a straight line by no more than 2 inches on either side.
Cut the Mirror
For Curves and Short Cuts
Curved or short scores can be cut with the running pliers. Lift one edge of the mirror. Place the edge of the mirror between the heads of the pliers. Line up the center groove on top of the pliers with the end of the score line. Gently squeeze the handles until the mirror separates at the score line.
For Straight Long Cuts
Carefully lift up one side of the mirror. Insert a thin item, such as the straightedge, under the mirror. The item should be placed parallel to and just underneath the score line. Secure the far end of the mirror with clamps or have an assistant hold it down. With one decisive motion, force the waste side of the mirror down. The mirror should break on the score line.
Tips for Cutting a Mirror
- Be sure to score from end to end. Otherwise, the break will not continue all the way across the mirror.
- Remember to use the cutting oil. You can even use a small brush to paint the intended score line with cutting oil.
- Buy an inexpensive mirror or piece of glass to practice cutting before you cut the mirror.
- If the glass cutter isn't scoring properly, the wheel may be dull. Some models allow for the wheel to be switched out for a new one.
- Rough edges can be smoothed out with fine-grit sandpaper or a stone knife honing block.
When to Call a Professional
Mirrors longer than 36 inches to 48 inches can be difficult to cut cleanly. Thick mirrors or mirrors with beveled edges may also require the assistance of a glass and mirror professional.