How to Fix Cracked Glass

Crack in Window Glass

the_burtons / Getty Images

Overview
  • Working Time: 15 mins
  • Total Time: 2 hrs
  • Skill Level: Beginner
  • Estimated Cost: $5 to $15

Cracked glass is often a fact of life when picture frames, mirrors, kitchen glassware, or door glass meet hard objects. Short cracks can rapidly develop into long ones that spell the end of the entire glass item. But you can quickly and inexpensively repair that glass and stay ahead of complete replacement with epoxy and a utility knife blade.

Fixing Cracked Glass With Two-Part Epoxy

The aim of do-it-yourself glass crack repair is to minimize the appearance of the crack and to contain the crack and prevent it from spreading.

Glass repair will not make the crack completely invisible from all angles. Rather, it is a cosmetic touch-up that reduces the visual appearance of the crack. When viewed from certain angles, the repaired crack may not be visible. From other angles, the crack will be visible.

Two-part epoxy consists of a resin and a hardener. Neither will work on its own. You'll need to squirt out the two substances and mix them together. For small repairs, it's best to buy epoxy in a double-cylinder syringe. This syringe regulates the flow of resin and hardener so that they remain within the correct proportion.

Whether gluing the glass in place or working with separate pieces of glass, you won't have to worry about excess epoxy. You'll leave the excess in place and let it fully cure. Once the epoxy has hardened, you will slice it off with a razor blade or utility knife blade.

What Kind of Cracked Glass Can You Repair?

Can Be Repaired
  • Single-pane glass

  • Mirrors

  • Glass tiles

  • Sidelites

  • Picture glass

  • Some kitchen glassware

Cannot Be Repaired
  • Double-pane windows

  • Microwave doors

  • Oven doors

  • Shower or tub glass

  • Automotive glass

Picture glass, door glass or door sidelites, single-pane windows, mirrors, and glass tile can be repaired with the two-part epoxy method. Kitchen glassware that will not be heated can often be repaired too.

Cracked phone or tablet glass can be repaired to a limited degree. Though the crack will be visible, the fix will prevent the glass from falling out and will stop a crack from lengthening. Plus, it will smooth over the crack and reduce sharp ridges.

Round impact cracks tend to repair best if they are no more than 1-inch diameter. Long cracks should be no more than 12 inches. Glass repair will only work on single pane glass.

Do not repair microwave door glass, double-pane windows, shower or tub door glass, or automotive glass with this method.

What You'll Need

Equipment / Tools

  • Utility knife blade
  • Nitrile gloves
  • Wooden craft stick
  • Safety glasses

Materials

  • Two-part epoxy
  • Glass cleaner
  • Painter's tape

Instructions

  1. Prepare the Work Area

    Lay clean cardboard on the work area. Work in a well-ventilated room. Because you have only five minutes of working time with epoxy, make sure that you have all of your tools nearby. All tools that you use should be disposable: work surface, gloves, and mixing stick.

  2. Clean and Dry the Glass

    The glass must be clean and free of residue for the glue to stick. Separating the broken pieces of glass and cleaning the edges is preferable, if possible. Otherwise, leave the broken pieces together. Let the glass thoroughly dry.

    Safety Tip

    Handle the glass with care if you decide to separate the pieces for cleaning. Always wear safety glasses.

  3. Prepare the Epoxy

    Snap off or cut off the ends of both of the two-part epoxy cylinders. Make sure that both cylinder nozzles are equally open. Squirt the epoxy on a clean working surface such as a paper plate. Thoroughly mix the epoxy with the wooden stick.

  4. Add the Epoxy to the Crack

    Glass That Is Separated

    If the two pieces of glass are separate, daub a small amount of epoxy along the broken edge of one of the pieces. Firmly hold the two pieces of glass together by hand as you add strips of painter's tape to the surface.

    Glass That Is Together

    If the pieces are together, gently force the epoxy into the crack with the stick, as if buttering bread. It is okay to leave a low hump of epoxy since it aids in the cutting process.

  5. Slice Off Excess Epoxy

    Once the epoxy has fully cured. slice off the excess with a loose utility knife blade or razor blade. Slide the blade at a low angle (about 15 degrees) to slice off the epoxy. Slide the blade away from your body. As long as the blade remains flush with the surface of the glass, the epoxy will remain at that level, too.

  6. Clean the Glass

    Use paper towels and glass cleaner to clean off fingerprints.