Long-lasting, versatile, and with a remarkable degree of heat resistance, epoxy adhesives can be used in almost any situation where you are required to glue two materials together like if you want to bind sub-floors, glue a detail to a larger structure or reinforce a fastener.
Epoxy can be used for a wide range of materials such as plastic, wood, metal, masonry, etc.
Continue reading about epoxies, why they play an essential role in construction.
Epoxy is a sort of polymer, a group of chemical compounds that consist of large molecules with repeating sub-units.
The molecular structure of polymers gives them the toughness, strength, and elasticity, making the polymers (both natural and man-made ones) ubiquitous in the daily life. Some of the polymers are wool, rubber, styrofoam, and epoxy.
Epoxy resins include epoxides—These are highly reactive groups of molecules that harden or cure through chemical reactions, which are either caused by combining it with other substances or by heating it at a high temperature.
This is the process through which an epoxy gets “Cross Linked” as the polymer strands form into a hardened structure.
Types of Epoxy Adhesives
There are two types of epoxy adhesives:
- One-part (or heat-cured).
- Two-part epoxies.
One-part epoxies cure faster. However, these are not as strong as the two-part epoxies. Now, let us understand both in detail.
Heat-cured epoxies are used in industries for various purposes. But this is not often used in the construction process because of the high-heat requirement for them to get cured. Even those that react to the lowest level of heat would need to be exposed to temperatures of at least 200 °F.
Because of its remarkable resilience, epoxy resins can be used in the products that range from electrical components and medical equipment to infrared telescopes and missile warning systems.
With two-part epoxies, the two components must create the chemical reaction packaged separately.
When the resin, often known as steel, is mixed with a hardener, the results will come up in 24 hours, transforming from a thick liquid to a putty and finally a fully cured and a hardened material.
(To remove epoxy after it has set, the next step is to scrape it off. First, soften it using alcohol or paint thinner, if needed.)
Two-part epoxies have many industrial uses – This is used in automotive, aeronautical, and other manufacturing areas. These are also especially common in boat building, construction projects, with applications including attaching countertops to substrates, fastening concrete elements to others either also of concrete or of stone or metal; securing decorative moldings in the place.
How to Choose an Epoxy Adhesive?
Epoxy packaging typically describes its content’s flexural, compressive, and tensile strengths in terms of the pounds per square inch (psi) that it can withstand. Consider your priorities when selecting an epoxy:
- If you are concerned with direct compressive resistance- It is the pressure that the epoxy can resist when being compressed from both ends. Give attention to compressive strength.
- If you are most concerned about the bonded materials, be able to bend without breaking, pay more attention to flexural strength.
- If you are concerned that the bonded materials cannot be pulled apart, then focus on the tensile strength.
The time it needs to cure varies among two-part epoxies. Also known as its “Pot Life” or “Work Time,” this is how long it takes for the adhesive to harden. For small projects, short pot life is said to be fine. For the ones that require more precision and when you may need to make adjustments, you would want a longer work time which will also give you more time to clean up the mistakes. Stronger epoxies will take longer to cure.
The viscosity of a material means how flowy it is. Water has high viscosity; molasses has low viscosity. If you are concerned that the adhesive may drip while it is setting, you would want one with a high viscosity – which is not flowy.
Most epoxies are waterproof when hardened, but some are specifically designed – that can cure even when those are exposed to water.
If you want to repair a hole or you want to repair a leaky connection between the pipes, go for adhesive that is designed for the task.
3 Alternatives to Epoxy Adhesives
Epoxies can be used to bind together many different materials and fill in holes.
There are some alternatives that you might want to consider either because other adhesives work better with particular materials or because you want something that is easier to work with than the epoxy system.
This is a neoprene rubber adhesive that can be used as a general adhesive but is especially effective when two nonporous materials are fastened together. Epoxies typically need to air dry which means they are often not the best choice, for example, gluing a laminate onto a countertop. Once the laminate is in place, air will not be able to reach the adhesive.
Instead of two different liquids, epoxy putty embeds the components in the putties of different colours.
Slice off a portion, knead the putty until it turns into one colour and then use it to make small repairs like cracks in pipes, chips in concrete and holes in damaged woodwork.
While the epoxy putty is quite strong and expensive, it is not intended for the structural because its tensile strength is of around 900 psi
Epoxy Adhesives – Pros and Cons
Epoxies are one of the many options when it comes to adhesives, though its strengths make it a popular choice in construction projects.
Advantages of Epoxy Adhesives
- Strength: The polymeric structure of epoxies helps in creating a remarkable strong bond – the one that is waterproof and is able to withstand high temperatures.
- Compatibility: Epoxy can work in binding a broad array of different materials while other common adhesives are more limited in their use. For instance, polyvinyl acetate glues require porous surfaces whereas epoxy resins offer greater flexibility.
- Speed: The curing time varies for epoxies, but for some fast-acting ones, it can also be under an hour for a functional cure.
Disadvantages of Epoxy Adhesives
- Complicated Application: Two-part epoxies require combining two different substances.
- Ventilated Spaces: Epoxy fumes are hazardous and you would want to limit their use to well-ventilated spaces. Also, many epoxies perform best when applied to air-dry surfaces.
Epoxy Coatings and Sealants
Epoxy’s special adhesive properties include durability, strength, and chemical resistance. It can also make it a tough protective coating or a sealant.
When the components are mixed together and sprayed over materials like the wood and concrete, it will resist abrasions as well as oil and other liquids.
High performance epoxy resins dry with smooth and clear finish.
Important Note: If you install an epoxy coating, you would want to keep an eye open for air bubbles which can form as concrete off gases inside the surface.
Other Uses of Epoxy Floors
Epoxy floor coatings and epoxy floors are two different things but have confusingly different names.
While an epoxy floor coating is a relatively thin layer of epoxy floor, the latter consists of a thicker (at least two millimeter) layer of epoxy that gives a strengthened, unbroke, and a glossy surface which can be installed using different colours.
These tend to be more common in commercial than residential places because their durability in high-traffic conditions justifies the extra expense.
Epoxy Paint or Acrylic Sealers
Epoxy paint also has a name that can be misleading. Unlike epoxy coating, epoxy paint or acrylic sealer is acrylic paint with a small amount of epoxy in it. It is more durable than the standard acrylic paint, but it does not have the strength similar to the epoxy coating. It is, however, less expensive and also dries faster.
To know more about epoxy, epoxy floors, or epoxy coating, contact the best epoxy flooring service provider in Melbourne i.e., The Tuff Build.