Challenges in Bonding Glass

Glass is a unique substrate that can prove challenging to bond when it comes to both hot melt and non-hot melt adhesives. When working with glass, you’re not often working with load-bearing seams. Instead, you’re likely completing a project that must hold up to regular environmental changes with a bond that remains invisible and flawless all the while.

Therefore, the adhesive you use to bond glass to either itself or another substrate must be carefully thought out. You want it to be strong enough to create a water-tight bond, flexible enough not to snap under multi-directional pressures and clear enough to not be easily seen-even years into the future.

At Noidsealant.com, we’re here to help you learn from our years of trials with glass and all the different kinds of hot melt and non-hot melt adhesives you can use to secure it. Here are several different types of adhesives and application methods to help you with a flawless glass installation, whether it’s on the job, in the factory or for an at-home DIY project.

Our Quick Recommendations

If you need a fast and reliable product recommendation, here are some of Shandong Noid Building Materials Co., Ltd.’s top adhesive solutions for bonding glass:

1. General Glass Bonding Applications:
🟢 Noid N-100 Neutral Silicone Structural Sealant
Ideal for bonding glass with metal, stone, and other materials. Offers excellent weather resistance, high transparency, and long-lasting adhesion.

2. Small-Scale and Indoor Glass Applications:
🟢 Noid MS-300 Modified Silane Sealant
Provides superior flexibility and adhesion, perfect for indoor glass installations such as windows, display cases, and partitions. Eco-friendly and odorless.

3. Large-Scale and Outdoor Weatherproof Glass Applications:
🟢 Noid PU-600 Polyurethane Sealant
Designed for curtain walls, glass facades, and automotive glass. Delivers high-strength bonding, exceptional waterproofing, and outstanding UV and aging resistance.

In the following sections of this article, we will explore the advantages and best-use scenarios of each adhesive when bonding glass.

Hot-Melt Adhesives for Bonding Glass

Hot Melt Glue Guns and Glue Sticks

In situations requiring precise application of a small amount of adhesive, people use hot melt guns to apply hot melt glue sticks. These applicators focus on achieving clean cut-offs and eliminating strings and trails. Operators often use them in narrow spaces for woodworking, packaging, bathroom and kitchen installations, and more.

But before you point and squeeze, take these measures to ensure a strong bond before applying your hot melt glue to a glass substrate:

First, triple-check that the glass is clean so the adhesive sticks directly to it—not to any oils or residues on the surface.
Next, roughen the bonding areas with an abrasive such as wet and dry paper. This helps the glue adhere more strongly and last longer.
Finally, use a hot melt glue stick specially formulated for non-porous, hard surfaces like glass. We recommend “The Noid” for a superior bond, even on slick surfaces.

We understand how challenging it can be to find the best adhesive for common substrates—let alone for glass, which demands flexibility, invisibility, and strength. At Noidsealant.com, we offer a wide variety of hot melt and non-hot melt adhesives and applicators to meet your specific needs.

Silicone Adhesives

Silicone sealant is a liquid form of adhesive that often looks, feels and acts like a gel. It comes in a variety of types including high-temp, electric-grade and multi-purpose. Silicone can be applied using commercial-grade extrusion devices, heavy-duty or crafting glue guns, along with hand-held caulking tools.

Since glass does not swell and shrink the way wood does, high-stress bonds—such as those in rigid glass applications—benefit greatly from using a flexible adhesive like silicone. Although silicone provides strong adhesion, its high flexibility and long curing time compared to many other hot melts make it more suitable for glass, car engines, and other tight-yet-flexible applications, rather than weight-bearing seals or surfaces that require painting.

Since it’s also weather resistant, waterproof and resists mildew growth, it’s very common to use silicone when bonding glass to itself, such as in aquariums or to wood or plastic like in window and bathroom installations. Silicone is truly a great adhesive for glass and a variety of other substrates – as long as you understand what kind of silicone you’re working with.

Acetoxy silicones release acetic acid and cure relatively quickly. Compared to most other silicones, they bond well with a variety of standard substrates. The acetic acid emissions can prove harmful to sensitive electronics and can prove corrosive in some applications, but some are also biocompatible and can be used in the manufacturing of medical devices.

Neutral curing silicones include oxime and alkoxy, which release methyl ethyl ketoxime and alcohol respectively as they cure. Unlike their acetoxy counterparts, this makes them non-corrosive and a great fit in electronic applications.

Non-Hot Melt Adhesives for Bonding Glass

Epoxy

An epoxy cure is the result of an exothermic reaction that cross-links polymers. Changing chemicals, temperature and other catalysts can transform the properties of this non-hot melt adhesive to fit nearly every application. This means an epoxy bond can be used on a variety of substrates, including glass.

Two-component, or two-part, epoxies are cured at lower temps than their one-component counterparts. These adhesives are superior in stability, temperature resistance and curing times. And better yet, two-part epoxies can be developed to be clear for use in highly-visible situations, such as glass installations.

The high stability combined with its ability to resist harsh chemicals and extreme heat makes epoxy an excellent solution in industrial settings, including aerospace and medical equipment.

Epoxies can be engineered to resist degradation caused by water, weather, ozone, oxygen, petroleum solvents, lubricating oils, jet fuels, gasoline, alcohol, salt solutions, mild acids and alkalis, and many other organic and inorganic compounds.