What’s the Difference between Fibreglass Matting and Chopped Strand Fibreglass?

When you are starting a project, it is important to have the correct materials, to ensure they do the job, and produce a high quality finish. There is often some confusion when it comes to fibreglassing as to what products should be used.

A common question is what is the difference between fiberglass matting, and chopped strand fiberglass? This is a common misconception, as they are actually the same thing, and equal in their properties, you generally may see it advertised as Chopped Strand Mat.

Chopped strand mat, or CSM is a form of reinforcement used in fiberglass consisting of glass fibers laid unsystematically across each other and then held together by a resin binder.

Chopped strand mat is typically processed using the hand lay-up technique, where sheets of material are placed in a mold and brushed with resin. Once the resin cures, the hardened product can be taken from the mold and finished.

Chopped strand mat has many uses, as well as advantages, over alternative fibreglass products, these include:-

Adaptability - because the binder dissolves in resin, the material easily conforms to different shapes when wetted out. Chopped strand mat is much easier to conform to tight curves, and corners than with a weaved fabric.

Cost -Chopped strand mat is the least expensive fiberglass, and is often used in projects where thickness is needed as the layers can be built up.

Prevents Print Through -Mat is, often used as the first layer (before the gelcoat) in a laminate to prevent print through (this is when the fabric weave pattern shows through the resin).

It is important to note that Chopped Strand mat does not have much strength. If you need strength for your project you should choose a woven cloth or you could mix the two. Mat however can be used between layers of woven fabric to help build thickness quickly, and aid in all layers bonding well together.