Adhesives for Fiber-Reinforced Plastic

Fiber-reinforced plastic or FRP is a composite material that uses fibers like carbon or glass to enhance the mechanical properties of the plastic matrix. Fiber-reinforced plastic is a lightweight and flexible material with a large amount of structural strength for use with high-impact and high-stress applications. It is also resistant to extreme temperatures, weather, chemicals, and corrosion. FRP can be made into complex shapes in various sizes, and it is paintable.

Bonding FRP

Adhesives are the primary means of bonding fiber-reinforced plastic. Fiber-reinforced plastic cannot be welded. Mechanical fasteners can also be problematic because they add to the overall weight of the finished product and can negatively impact the structural integrity of the material when being drilled into place.

Because gluing fiber-reinforced plastic is so common, there are a variety of adhesives for FRP available. If you choose the right adhesive for the part of the plastic you are using and the application needs, you can get strong and lasting bonds when you apply it as recommended.

Recommendations for Fiber-Reinforced Plastic Adhesives

Because there are so many glues for FRP, we want to help you narrow down your choices. Our team of adhesive experts shares a few trusted adhesives for FRP and when to use them.

Epoxy: EP 420 High-Strength Epoxy
Epoxies are known for their great strength. If you have a demanding, high-performance application, then this product may be right for you. It has a high level of both shear and peel strength as well as great impact, shock, and vibration resistance. With a working time of 20 to 30 minutes, this adhesive allows for the repositioning of components and is great for bonding larger surface areas.
Fast-Cure Epoxy: EP 110 Epoxy
If you want both strength and speed, try the 110. It has the high strength of an epoxy but with a shorter open time of only ten minutes. This adhesive also offers a high resistance to chemicals and weather for applications exposed to harsh environments.
Epoxy: 3M DP420 Epoxy
A great 3M epoxy for fiber-reinforced plastic, this adhesive is known for its high shear and peel strength. It has a work life of around 20 minutes to allow for adjustments during the bonding process. This product also has a low-odor formulation and meets UL 94 HB standards for a more comfortable and safer working environment.
MMA: Infinity Bond MMA 420 Glue
This product is a great adhesive to use for FRP because of its versatility. Not only does it form strong bonds that are impact-resistant and shock-resistant, but it also has a fast set time of around five minutes. This adhesive is also compatible with a wide temperature range and is resistant to many chemicals. It is a common choice for many composite applications.

While all the above products are great options for FRP glues, every application is different, and the best adhesives for your needs may not be on this list. If you need help determining what product is best for you, we want to help. With over fifty years in the adhesives industry, we can provide you with a customized product recommendation at no cost.

How to Choose a Glue for FRP

To start, there are several different types of glues for fiber-reinforced plastic applications. Epoxy adhesives are a common option when strength is the biggest concern. MMA adhesives are also a popular choice because they provide a nice balance of strength and flexibility. These adhesives also have the added bonus of needing minimal surface preparation. Urethane adhesives may be another option. These adhesives are relatively flexible and tend to have high impact and vibration resistance.

Because there are several adhesives for FRP available, you need to be mindful of your specific needs. The following are all factors you should consider when trying to find the best adhesive for your FRP application:

Specific application
Strength
Flexibility
Bonding environment
Application method
Cure time
Environmental resistance
Temperature range
Special properties
Budget

You can refer to an adhesive's technical datasheet for more details. Finally, you should always test the FRP adhesive on your application to ensure it is compatible with your substrates and can withstand the bonding environment.

How to Bond Fiber-Reinforced Plastic

It is relatively easy to glue fiber-reinforced plastic when you use the right adhesive and apply it as recommended. While MMAs usually require minimal surface preparation, epoxies and other structural adhesives generally require a few more steps for best results.

Degrease and clean the substrate with a solution like isopropanol.
Lightly abrade the surface with something like carborundum paper or a hand pad.
Degrease and wipe down the substrate again to remove any contaminants remaining after abrasion.
Apply the adhesive as recommended by the manufacturer, including in an acceptable range for air temperature and humidity.

Get the Best FRP Adhesive for Your Needs

Not sure if one of the products mentioned above is right for your needs? This is where we can step in. We have been in the business of adhesive bonding since 1971 and have the expertise to point you in the right direction. Reach out to us today to get a free, no-obligation product recommendation.