How to bond fiber reinforced plastic

How to bond FRP (fiber reinforced plastic)?

FRP is a composite material with extremely high structural strength making it popular for high impact or highly stressed applications.
It is lightweight, and there is a strong requirement for adhesives to bond FRP as it cannot be welded, and mechanical fasteners
not only add to the component weight, rattling, and vibration loosening but can affect the structural integrity of the material if it has to be drilled.

FRP Uses

  • Tanks and vats
  • Marine
  • Construction
  • Theme park scenery

1. Degrease with Permabond Cleaner A or isopropanol (do not use meths or white spirits as this can leave a residue).
2. Lightly abrade by one of the following methods
-Wet and dry grit paper (carborundum paper) 320 grade recommended.
-Red Scotchbrite pad
3. Lastly, degrease again to remove any contamination or loose particles.
It is OK to bond as received, but if you wish to have a consistent bonding surface and better mechanical keying of the adhesive, then it is recommended to carry out this surface preparation.

What is the best adhesive to bond fiber reinforced plastic?

bond FRPSeveral types of adhesives bond well.  Understanding the desired cure process, as well as what the bond will need to endure, will help to choose the best adhesive for each FRP bonding application.

Cyanoacrylate – also known as instant adhesives, super glue, crazy glue, ca glue, etc. For bonding FRP fiber reinforced polymer consider a black, toughened grade such as  735 low viscosity or 737 medium viscosity. Note Permabond 731 is a clear, toughened grade.  Often FRP can have a very rough surface. Use caution not to exceed the gap fill capacity of the cyanoacrylate.

Single component epoxies – Single component epoxies may not be the best choice as they cure with heat which may exceed the FRP heat rating and often parts are too large to easily put in an oven.

Two component epoxies – Permabond two component epoxies bond FRP.

Structural acrylics – Permabond structural acrylics bond FRP – however, if the surface is rough, consider a two component mixable grade as opposed to surface activated as the rough surface may create too large of a gap.

Polyurethane adhesives – All Permabond polyurethane adhesives offer high strength, high peel strength, and good impact resistance.

With so many choices of adhesives to bond carbon fiber, the desired cure process, the desired environmental resistance, and the desired temperature resistance are key factors in choosing the best adhesive for each application.

Contact Permabond for an adhesive recommendation for your application.



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