Repairing glass sounds straightforward, but it’s not always so simple. First, you must know what kind of environment and pressure the glass regularly undergoes to pick the proper adhesive for your project. Choosing the wrong one could mean redoing an entire repair or risking injury when the glass breaks.
Gorilla Glue is the best superglue for minor repairs. However, it’s not good under high temperatures, or waterproof. Epoxy is slow to cure but can withstand extreme temperatures. Silicone is the middle adhesive, being waterproof and tolerant of high temperatures, and it cures within 24 hours.
Selecting an adhesive for glass repair can be daunting once you start looking at it. You need to understand how much pressure and stress the glass will be under and what environment it typically stays in. You also need to consider how it will be applied and how long it takes to cure. Now let’s get to it!
Which Type of Glue is Best for Repairing Glass?
For small jobs, you can’t go wrong with Gorilla Glue (on Amazon). Gorilla Glue is the epitome of glue for minor repairs from glass, wood, foam, and ceramic. Its unique formula dries for an exponentially strong bond that ends up clear and invisible to mend the breaks.
For the best application, apply it at room temperature and give it at least two hours to dry, although it does take 24 hours to cure completely.
Despite how well Gorilla Glue works, you want to avoid it if the surface gets wet often or has a high-temperature exposure. It’s not waterproof and doesn’t work well at high temperatures or on plastic.
What to Think About When Choosing a Glue
Indoor vs. Outdoor Usage
Glass is found in both indoor and outdoor areas, which draws into question where the glass will stay when you need to select an adhesive.
For an outdoor repair, you must ensure the adhesive can withstand extreme hot and cold temperatures and direct sunlight and water exposure.
For this reason, it’s best not to use superglue in outdoor applications unless you get a specifically formulated kind that states it’s waterproof.
Unfortunately, these superglues are rare and often expensive, as the less water-resistant superglue is more popular. So instead of using superglue, try a silicone or epoxy adhesive that can hold up to extreme temperatures and moisture.
Drying Time
Drying time can refer to different points of the gluing process. However, the setting time is the time it takes for the adhesive to harden.
It is considered cured when the adhesive achieves maximum bond strength with the glass. Some glues can even set and cure almost instantly, while others, like epoxy, can take several days to fully finish.
If you need a quick-curing adhesive, superglue is your best bet. It dries and cures almost instantly.
The next fastest method is silicone, which takes 24 hours to cure completely, but can take several days with a thicker application. Epoxy is the last and most extensive adhesive, which takes an entire week before it cures.
Bond Strength
The bond strength is determined by lap shear strength and peel strength, which indicates the adhesive’s ability to withstand stress.
A lap shear test will measure the adhesive’s ability to withstand stress when the glue is forced to move laterally. At the same time, the peel strength measures the adhesive’s strength under perpendicular pressure. Both put together will then indicate the bond strength of the glue.
With glass repair, different things can affect bond strength. For instance, repairing a glass windshield exposes the glue to more stress than if it were in a picture frame, requiring differing bond strengths.
So it’s essential to consider what the use of the repaired glass will be and how much pressure will be applied to the finished product.
Waterproof
There are varying degrees when it comes to moisture levels that glue can tolerate. Some are water resistant, while others are waterproof.
Therefore, it’s important to note how much moisture your repaired glass will come in contact with when determining what adhesive to use.
Superglue is a good water-resistant glue, but prolonged exposure to moisture can degrade the glue and deteriorate the adhesive bond.
On the other hand, epoxy could be waterproof and water resistant, depending on the type of epoxy you purchased.
If there is prolonged water exposure, it is vital to ensure the epoxy you bought is meant for that application. For example, marine epoxy is a great choice if the glass will be submerged.
The best choice for a waterproof adhesive is silicone. It is usually used as a sealant in high-moisture areas like bathrooms, kitchens, aquariums, and roofs.
Temperature Resistance
High temperatures can decrease the ability of an adhesive to maintain that strong bond. Glass Transition Temperature, or Tg for short, is the temperature at which an adhesive stops being hard and begins to form a rubbery texture when it breaks down.
Epoxy and silicone offer great solutions to repair glass undergoing harsh conditions, while superglue breaks down quickly in high temperatures.
Application
Consider how the adhesive will be applied when looking for the glue to repair your glass. Super glues can be done in one step, in several different ways, and have fast drying and curing times.
Silicone adhesives require a caulking gun, which adds an additional product you need to buy, and epoxy requires mixing two substances together and working quickly.
Superglue
Cyanoacrylate adhesive, more commonly known as superglue, works on almost anything, including glass. Superglue consists of acrylic resins that can repair tiny cracks, chips, and breaks, making it an excellent tool for minimal repairs.
Superglue cures almost instantly with its strong bond to the hydroxyl ions in water, making it a quick and effective adhesive.
However, when planning to use superglue, you want to be sure there will be zero moisture, and it won’t be exposed to high temperatures.
Epoxy
Epoxy glue has two parts: resin and a hardener. Mixing the two substances then creates a chemical reaction that prompts polymerization, which is a bond at a molecular level. Epoxy is a popular choice for glass repair because of its strong bond and clear finish when it dries.
The problem with using epoxy is that after the resin and hardener are mixed. The formula begins to solidify almost immediately, requiring a quick application before a new batch is needed to be mixed.
However, when this mixture does harden, it forms an ultra-hard and long-lasting hold that can stand against extreme conditions.
Silicone
The last popular choice for adhesive in glass repairs is silicone. Its highly flexible, waterproof, and easy-to-apply nature makes it a great choice. It’s typically used as a sealant in aquariums, window frames, vehicles, and even appliances.
Silicone is a truly well-rounded adhesive that can be found in many areas of your home.
It starts with a gel-like consistency and hardens as it dries. Waterproof and mildew-proof, this is usually the choice of adhesive for glass repairs that will be in a constant wet condition. Silicone can also withstand extreme heat and harsh environments, making it great for indoor and outdoor applications.