Epoxy Adhesives 101: Where and How to Use Them

Polymerisation is at the heart of one of the most commonly used adhesives today, and that’s epoxy. This chemical process forms a solid and inflexible bond between two objects. The bond that epoxy glue can create is able to resist chemicals, heat, and everyday wear. No matter how rough the conditions are, the adhesive lasts thanks to its high shear and tensile strength. This is the case in many different applications and on different materials, as long as you know how to apply epoxy adhesives.

Materials You Can Use Epoxy Adhesives on

Glass

While not the usual substrate for epoxy to be used on, glass pieces can be bonded together. If you do so, the bond is transparent once the adhesive is cured, and for the adhesive to cure properly, the pieces should not be moved during said process. Reliable epoxy adhesive glue used on glass adheres best when the surface is slightly scraped.

Metal

A more prominent material used with epoxy glue, metal itself offers a rigid, solid structure. Epoxy creates a solid bond, especially between two metal pieces, making it suitable for attaching brackets to structural objects like frames.

Wood

Be it for a wooden dresser or flooring, epoxy adhesive can be used on wooden surfaces as the material itself is porous. This means the adhesive can somewhat soak into the wood, which improves the grip between the two surfaces being bonded together, making epoxy adhesives ideal for repairs of furniture and inlays.

Ceramics

Anything from cracked lab components and ceramic pieces to tile backsplashes, epoxy can be used to bond ceramics without issue. They also align quite well when left to cure in peace. You don’t have to spend on getting new tiles or a completely new Büchner funnel.

Plastic

While epoxy adhesives work well with the above materials, when it comes to plastics, they can get a bit cumbersome. When it comes to rigid plastics such as ABS and PVC, you won’t have issues bonding them. However, when it comes to polyethylene, polypropylene, or plexiglass, the oils and coatings they contain can cause issues with adhesion.

Applications of Epoxy Adhesives

Industrial

When it comes to manufacturing plants and construction sites, epoxy-based glue is valued for its chemical resistance and structural integrity. Since both applications require most, you can see epoxy being used with anchor bolts found in concrete foundations, as well as to seal parts of aircraft interiors or vehicle body panels.

Marine

Since epoxy is water-resistant, using it in the marine world can help keep a vessel afloat. When paired with a protective marine-grade topcoat, an epoxy adhesive can make a big difference even during changes in humidity.

Lab

Since epoxy adhesives can be used on ceramics, it means you can use them for precision work in a chemical lab. You can join balance tables with countertops coated in epoxy or seal a phenolic resin sink or an epoxy pegboard. You don’t have to worry about chemicals eating away at the adhesive or flames doing any harm to its bond.

DIY

Even as a hobbyist, you can use epoxy adhesive glue since it’s ideal for quick, easy fixes at home. Be it loose electronic parts, furniture cracks, or sealing wood slabs on a river table. As long as you keep playing to epoxy’s strength, you can use it in various projects.

How to Use Epoxy Adhesive

Preparation

Once you’ve selected the correct adhesive for the materials you want to bond, the first step is to prep the surfaces on which the epoxy will be applied. Preparation is key to a successful and long-lasting bond. Cleaning the materials from oils, dust, and lightly roughening them with sandpaper is a must.

Mixing

When both surfaces have been prepared for the adhesive, it’s time to prepare the adhesive itself. This involves mixing the resin and hardener, with most epoxy adhesives requiring a 1:1 or 1:2 mix. Make sure to check the adhesive packaging to make sure that’s the exact ratio. The mixture should be mixed in one direction for a minute to avoid weak bonds or tackiness.

Application

To apply the adhesive, you’ll need a plastic spreader, a syringe, or a brush, depending on where and what you’re using it for. If you want better precision, a syringe is your best option, while spreaders are great for an even coating over large flat areas. Brushes are best when you need to apply epoxy glue on complex surfaces.

Curing

To let the adhesive dry is one thing, but to let it cure, you need to set the right conditions. While room temperature is usually okay, if temperatures drop, the process can be slowed down significantly. Heat curing is a good alternative, but keep an eye on temperature changes affected by external factors.

Clean up

When you’re done with all of the above processes, clean around the application area using either isopropyl alcohol or acetone. This way, any excess adhesive can be easily removed from the surface and your tools.