What's the difference between fiberglass mat and cloth?

Do you have a project in mind but have no idea where to start? Let us help you. One of the first things you will want to do is decide what kind of fiberglass you want to use. Do you need to build up thickness fast? Are you concerned about strength? Do you have tight corners you are working with? Let us break things down a bit to help you decide if fiberglass cloth is right for your project or if you are needing chopped fiberglass mat. Keep in mind that you can actually use both together to achieve your desired outcome. Here is an overview -

Fiberglass is a composite material that includes extruded filaments of glass fibre. The fiberglass used in the automotive industry and in boat building and hull repair is different from the fiberglass used for building insulation. Rigid fiberglass can be held together with an epoxy resin. The difference in fiberglass cloth and mat is in the way it is constructed and in its appearance.

The ancient Egyptians and Phoenicians experimented with creating and using fiberglass. In 1880, fiberglass cloth was developed that was both durable and flame retardant. During the 20th century, fiberglass was improved and used as reinforcement in plastic laminates. When polyester resin was created, it was combined with fiberglass to form a fiberglass composite. In 1953, the first vehicle with a body made completely out of fiberglass for reinforced plastic was created, the Chevrolet Corvette.

Fiber glass mat usually comes in large carpet-like rolls and is used for automotive and boat projects. It can be used to install speakers in a car while making a mold for them, or it can be used to repair the body of a marine vehicle. Fiberglass cloth has a smoother-looking finish, excellent for water-proofing wood or other surfaces when combined with resin. Fiberglass is also used in a variety of household fixtures, like shower stalls and bathtubs.

MAT FABRICS

Chopped Strand Mat (also known as fiberglass mat) has short strands of fibers held together with a resin binder. The fibers are randomly oriented. Mat is only compatible with polyester and vinyl ester resin. When resin is added to the mat, the binder dissolves and the fibers can be moved around. It is easier to conform mat to tight curves and corners than it is with weaved fabric. The reason chopped strand mat is not compatible with epoxy resin is because the binder holding the fibers together needs styrene to properly dissolve. Polyester and vinyl ester resins have styrene in them. (There are some places that sell chopped strand mat that is compatible with epoxy but it is hard to come by and much more expensive). 

Chopped strand mat is the least expensive fiberglass and is often used in mold construction or projects where thickness is needed. Mat is often used as the first layer (before the gelcoat) in a laminate to prevent print through. Print through is when the fabric weave texture shows through the resin. Chopped Strand mat does not have much strength. If you need strength you should choose a woven cloth or you could mix the two. Mat can be used between layers of woven fabric to help build thickness quickly and aid in all layers bonding well together. If you have any questions feel free to comment. We will do our best to reply with an answer. Or, you can visit our product website HD Fiberglass for more information.

WOVEN FABRICS

Woven fabrics are strong reinforcements because the fibers are bundled into yarns oriented in just two directions. The warp and fill yarns run at 0 and 90 degrees respectively. Thus, fabrics are anisotropic, or strong in only two directions. Fabrics need to be oriented so the fiber yarns run parallel to the expected loads. If extra strength is needed in a different direction, another ply must be added at an angle to the first. The most common angles are +/- 45 degrees.

Caution