How to Repair Cracked Glass

Repairing cracked glass may seem daunting, but with the right supplies and techniques, it can often be fixed at home. This guide will provide detailed instructions on how to repair cracked glass using different methods depending on the type and extent of the damage.

Assessing the Crack

The first step is to thoroughly examine the crack to determine the best repair method. Consider the following:

  • Location – Is the crack in a window, tabletop, or other furniture? Curved pieces like vases or lamps? The repair technique will vary.
  • Size – Is it a small chip, a long crack, or a full break? Larger cracks need more extensive repairs.
  • Depth – How deep does the crack extend? Surface-level cracks are easier to fix than deep cracks extending through the glass.
  • Origin – Identify the starting point and follow where the crack extends. This helps determine the repair approach.
  • Glass type – What kind of glass is cracked? Annealed, tempered, laminated? Some glass cannot be repaired.

Once the damage is fully assessed, you can decide on the best repair method.

Cleaning the Glass

Before beginning repairs, clean the glass thoroughly around the crack. Any dirt or debris left in or around the crack area can prevent adhesives and epoxies from properly bonding and sealing.

Follow these steps to properly clean the glass:

  • Wear gloves to protect your hands from sharp glass.
  • Carefully wipe away any loose glass fragments.
  • Use a vacuum nozzle or tweezers to remove debris from the crack itself.
  • Fill a spray bottle with warm water and a small amount of mild dish soap. Spray the crack and surrounding area and let it soak for 5-10 minutes.
  • Scrub the crack and glass with a soft brush or sponge to dislodge any stuck particles.
  • Use a microfiber cloth to wipe the area completely dry. Make sure no moisture remains in the crack.
  • Finish by wiping the area with 90% isopropyl alcohol to remove any oily residue.

Thorough cleaning is vital for the repair adhesives to work effectively. Now the glass is ready for crack repair.

Repairing Small Cracks and Chips

For small cracks less than 3 inches or minor corner chips, you can likely repair them neatly with glass repair epoxy. It easily fills the crack and bonds the glass together.

What You’ll Need

  • Glass repair epoxy/adhesive
  • Epoxy applicators (like toothpicks)
  • Sandpaper and emery board
  • Razor blade

Steps to Repair Small Glass Cracks

  1. Prepare the crack – Ensure the glass is entirely clean and dry around the crack. Cover areas where you don’t want epoxy to spread.
  2. Mix the epoxy – Follow the product instructions to combine the adhesive resin and hardener on a disposable surface. Obtain an even color to indicate proper mixing.
  3. Fill the crack – Use an applicator like a toothpick to fill the entire crack area with epoxy. Apply slightly more than needed to account for shrinkage.
  4. Spread the epoxy – Drag the applicator across the crack to spread the epoxy evenly and remove excess. Spread it into a dome shape.
  5. Let it cure – Leave the epoxy undisturbed while it cures, usually 24 hours. The application surface will feel solid when fully cured.
  6. Sand and finish – Lightly sand any uneven epoxy and smooth with an emery board. Carefully scrape off any unwanted areas with a razor.

With practice, you can achieve almost seamless chip and crack repairs this way. Larger cracks may require more preparation.

Preparing Larger Cracks for Repair

For cracks over 3 inches or that extend through multiple layers, the glass needs stabilization before filling the crack space. This prevents further spreading during the repair process.

Supplies Needed

  • Glass repair epoxy
  • Epoxy applicators
  • Razor, sandpaper, emery board
  • Painter’s tape
  • Fine-tipped glue injector
  • Two-part epoxy glue

Steps to Stabilize Large Cracks

  1. Clean and dry the glass thoroughly in and around the crack using the steps previously covered.
  2. Apply painter’s tape along both sides of the crack to act as a dam and prevent leaking as you inject epoxy.
  3. Mix two-part epoxy glue following the instructions. Load the glue into a fine-tipped injector.
  4. Inject epoxy deep into crack – Slowly squeeze glue into the crack at multiple points from bottom to top. Fill it fully.
  5. Spread excess glue that seeps from the crack using an applicator. Create a thin, even layer.
  6. Allow the epoxy to cure for at least 24 hours until completely hard and bonded with the glass.
  7. Remove tape carefully with a razor blade once the glue has hardened. Sand away any uneven edges.

The crack is now stabilized and ready to fill. This provides the necessary foundation for a smooth finish.

Filling Large Stabilized Cracks

Once the crack has been properly stabilized, it’s ready to be filled for a seamless repair. This provides great results for cracks over 3 inches or through multiple glass layers.

Supplies You’ll Need

  • Glass repair epoxy
  • Epoxy applicators
  • Sandpaper & emery boards
  • Painter’s tape
  • Plastic spreader/putty knife

Steps for Filling Large Stabilized Cracks

  1. Outline the area with painter’s tape to prevent epoxy drips during filling.
  2. Mix epoxy thoroughly – Combine equal resin and hardener amounts until the color is consistent.
  3. Fill the crack fully with epoxy by pressing it deep into the space with an applicator. Overfill slightly.
  4. Spread smoothly – Use a plastic spreader to smooth the epoxy flush with the glass surface. Remove any excess.
  5. Let the epoxy cure undisturbed for at least 24 hours before sanding or finishing.
  6. Sand and finish – Once fully cured, lightly sand any uneven areas. Polish smoothly with an emery board.

Take care not to leave any unsightly bumps or ridges in the epoxy. When done correctly, the repair will be barely noticeable.

Fixing Stress Cracks in Windows

Stress cracks in windows occur over time from factors like temperature changes, wind pressure, and shifts in the window frame. Repairing them properly requires relieving pressure on the glass.

What You’ll Need

  • Glass repair epoxy
  • Epoxy applicators
  • Painter’s tape
  • Plastic or nylon window shims
  • Shimmy tool
  • Mallet

Steps to Repair Window Stress Cracks

  1. Protect the area around the crack with painter’s tape to prevent epoxy drips.
  2. Install shims above/below crack – Use a shimmy tool and mallet to insert shims to relieve pressure on the glass.
  3. Fill the crack with epoxy – Use an applicator to fully pack the crack space with repair epoxy.
  4. Spread the epoxy – Drag an applicator across to create an even dome shape. Remove any excess.
  5. Allow the epoxy to cure – Leave it undisturbed for at least 24 hours to harden completely.
  6. Carefully remove the shims once the epoxy has fully cured and regained strength.
  7. Finish and polish the area with fine sandpaper and an emery board if needed.

Relieving the pressure on the window prevents the crack from spreading further during the repair process.

Fixing Cracked Glass Tabletops

Tabletops made of tempered glass can develop cracks over time from heavy objects or shifts. Fortunately, you can often repair these without replacing the entire top.

What You’ll Need

  • Clear packing tape
  • Glass repair epoxy
  • Epoxy applicators
  • Sandpaper & emery boards
  • Painter’s tape
  • Acetone

Steps to Repair Cracked Glass Tabletops

  1. Stabilize underside of crack – Apply clear packing tape along the crack on the underside of the glass.
  2. Clean the top side – Use acetone to fully clean the top side around the crack.
  3. Outline the area with painter’s tape to protect the surrounding glass surface.
  4. Fill the crack with epoxy – Pack the space fully with epoxy adhesive using an applicator.
  5. Spread smoothly – Drag an applicator across the epoxy to create an even dome shape.
  6. Allow to cure – Leave the epoxy undisturbed for a full 24 hours to harden.
  7. Sand and polish the epoxy with sandpaper once cured. Use an emery board to smooth.
  8. Carefully remove tape. Check that the underside tape remains intact.

This can successfully repair cracks and prevent further spreading to restore tabletops.

When to Call a Professional

While many glass cracks and breaks can be repaired at home, some may require calling a professional:

  • Deep cracks – If the crack penetrates deep through multiple glass layers, a pro may better assess and repair it.
  • Shattered/splintered glass – Damaged glass that is splintered into many pieces is complex to repair.
  • Large holes or missing glass segments – Any holes bigger than a quarter or missing glass segments often need professionals.
  • Tempered glass – Cracks in tempered glass can be difficult or impossible to repair at home.
  • Annealed glass – Only professionals can work with annealed glass as it requires specialized tools.
  • Valuable glass items – For expensive, rare, or sentimental glass items, professionals provide the best care.
  • Safety concerns – Cracked glass in doors, heavy furniture, or vehicles poses safety risks for DIY repairs.

Don’t hesitate to call a professional glass repair company to evaluate the damage if you feel unsure about undertaking repairs yourself.

Tips for Preventing Glass Cracks

While glass cracks and breaks are common, there are things you can do to help prevent them from occurring:

  • Handle glass items very carefully to prevent chips and cracks – don’t bang or bang.
  • Avoid setting hot dishes or pans directly on glass tabletops – use trivets.
  • Use soft close hinges on any glass cabinet doors to prevent slamming.
  • Keep glass properly secured in frames/windows and lubricate tracks – don’t let it vibrate.
  • Protect glass tabletops and other surfaces from scratches and bumps.
  • Immediately clean any nail polish, paint drips etc from glass surfaces.
  • Inspect glass for any minor chips or flaws and address them quickly before they spread.
  • Maintain stability beneath glass tables and shelving to prevent shifting and cracks from stress.
  • Use shades or curtains to reduce intense sun exposure on glass windows and reduce temperature fluctuations.

With proper care and handling, glass can last a very long time without cracks and damage. But if cracks do occur, this guide covers proven methods for repairing them successfully.

Frequently Asked Questions About Repairing Cracked Glass

Can all types of glass be repaired?

No, some glass like tempered or laminated glass can be very difficult or impossible to repair properly at home. Annealed glass also requires professional tools. Standard window glass, tabletops, and household items can often be repaired.

What’s the best glue for repairing cracked glass?

Specialized glass repair epoxy is the best adhesive. It flows evenly into cracks, dries clear, and firmly bonds the glass together. Super glue and regular epoxy don’t provide the same quality crack filling.

How long does epoxy take to dry when repairing glass?

Most glass repair epoxy takes 16-24 hours to fully cure and harden. Avoid disturbing or handling the glass during this time. Shortcuts can weaken the bond and repair.

Should I use tape when repairing a cracked window?

Yes, painter’s tape can help stabilize cracks and prevent leaking when injecting epoxy. It also protects the area from drips when filling a crack. Remove any tape once the epoxy has hardened fully.

Can I repair a chip or crack from both sides of the glass?

No, adhesives and epoxy will not bond correctly if applied to both sides of a crack. Repair only from the least visible side for proper filling and strength.

How should I smooth the epoxy over a filled crack?

Use a plastic spreader, putty knife, or old gift card to evenly spread the epoxy flush with the glass surface when filling a crack or chip. This provides the smoothest finish.

How can I remove excess dried epoxy from glass?

Carefully scrape it away with a sharp razor blade. Be cautious not to scratch the glass surface. An emery board can also sand down any small hardened epoxy bumps.

When should I avoid DIY glass crack repairs?

If the glass is severely cracked, shattered, or missing pieces it’s safest to call a professional. Cracks larger than 3 inches or impacting your safety also warrant hiring a glass repair company.


Repairing cracked glass may appear challenging, but using the proper adhesive products and techniques, many household items can be fixed successfully. Carefully assess the damage, stabilize larger cracks, and thoroughly fill the space with a specialized epoxy. Allow proper curing time for maximum strength. With some patience, most glass cracks and breaks can be repaired securely at home and restore beloved items. Handle glass gently, act quickly at first signs of cracks, and consider calling on professional services when needed.


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