Glass or Carbon Fibres

The main difference between MAT and woven reinforcement fabrics lies in the arrangement of the fibres and the mechanical properties they provide once laminated with resin.

MAT, also known as chopped strand mat, is made of randomly distributed chopped glass fibres bonded together with a binder. Thanks to this structure, it easily conforms to curved surfaces and complex shapes, making it one of the most widely used materials for repairs, mould production, tanks, boats and glass fibre reinforced polyester parts.

Woven fabrics, on the other hand, are made from continuous fibres interlaced in a specific pattern. This arrangement provides greater mechanical strength, improved load distribution and a more uniform surface finish. Woven reinforcements are available in glass fibre, carbon fibre and aramid (Kevlar®), with different weave styles designed for specific applications.

In general, MAT is preferred when ease of use, fast lamination and cost-effectiveness are the main priorities, while woven fabrics are the best choice when higher structural performance or a better strength-to-weight ratio is required.

Carbon fibre generally offers greater stiffness and a better strength-to-weight ratio than glass fibre. This means that, for certain applications, it allows the manufacture of lighter components while maintaining excellent mechanical performance.

For this reason, carbon fibre is widely used in industries where weight reduction and high performance are critical, such as motorsport, automotive engineering, aerospace, marine applications, drones, sporting equipment and advanced technical components.

However, carbon fibre is not always the best choice for every project. Glass fibre remains one of the most commonly used composite reinforcements because it provides excellent strength, is more affordable and is easier to work with in many applications, including repairs, mould making, tanks, swimming pools and boat construction.

The choice between carbon fibre and glass fibre depends on the intended use of the part, the desired weight, the required stiffness and the available budget. If maximum performance and low weight are the priority, carbon fibre is often the preferred option. If you are looking for a durable, versatile and cost-effective solution, glass fibre is usually the most practical alternative.

Yes. Glass fibre is fully compatible with epoxy resins and, in fact, this combination is widely used when higher mechanical performance is required than that offered by conventional polyester resins.

Epoxy resins are known for their excellent adhesion, high mechanical strength and good chemical resistance. They also tend to shrink less during curing, helping to produce stronger, more dimensionally stable and more accurate composite parts.

The combination of glass fibre and epoxy resin is commonly used in marine, aerospace, sporting and industrial applications, as well as in repairs where long-term durability is important. It is also frequently chosen for the manufacture of high-quality moulds and prototypes.

Although epoxy resin generally provides superior performance, polyester resins remain an excellent choice for many projects thanks to their lower cost and ease of use. The best option will depend on the technical requirements, the working environment and the available budget.

The number of layers required will depend on the type of fibre used, the fabric weight, the resin selected and the performance requirements of the finished part. There is no single answer that applies to every project.

For light repairs or cosmetic applications, two or three layers may be sufficient. However, structural components exposed to significant loads, impacts or vibration may require several additional layers to achieve the desired strength and stiffness.

It is also important to remember that the final performance does not depend solely on the number of layers. The type of reinforcement, fibre orientation, lamination quality and proper resin impregnation all play a key role in the finished result.

In many situations, using fewer layers of a heavier fabric can be more efficient than applying numerous lightweight layers. For this reason, the choice should be based on both the required final thickness and the mechanical demands of the application.

If you are unsure about the amount of material needed for your project, our team can help you choose the most suitable combination of fibre, fabric weight and resin.

Fabric weight, usually expressed in grams per square metre (g/m²), indicates how much fibre is contained in the reinforcement material. It is one of the most important factors when designing a composite laminate, as it directly influences thickness, strength and overall performance.

Lighter fabric weights are commonly used for fine finishes, lightweight parts and complex shapes where the reinforcement must easily conform to curves and contours. They are also often used in the first layers of a laminate to achieve a smoother surface finish.

Heavier fabric weights provide greater thickness and strength with fewer layers, making them suitable for structural components, major repairs and applications that require increased rigidity and durability.

The right fabric weight depends on the type of project, the loads the part will be subjected to, the desired finish and the balance you wish to achieve between weight, strength and cost. In many cases, different fabric weights are combined within the same laminate to optimise performance.

If you are unsure which fabric weight is best suited to your project, our team can help you select the most appropriate option based on the type of fibre, the resin system and the required performance.

Yes. Carbon fibre can be painted once the lamination process has been completed and the surface has been properly prepared. In fact, many carbon fibre components are painted to provide additional protection or to match the final appearance of the product.

Before applying paint, the surface should be fully cured, clean and lightly sanded to ensure good adhesion. In many cases, a primer specifically designed for composite materials is also applied to improve the final finish.

However, one of the most appreciated features of carbon fibre is the distinctive appearance of its woven pattern. For this reason, transparent clear coats are often used in automotive, marine and sporting applications to preserve the visible carbon weave while protecting the component from moisture, chemicals and ultraviolet radiation.

If the part will be exposed to outdoor conditions for extended periods, it is recommended to use paints or clear coats with UV protection. This helps maintain both the appearance and the surface properties of the laminate over time.

Whether the part is painted or left with a visible carbon finish, proper surface preparation is essential to achieve a durable and professional result.

For most marine repairs, glass fibre remains the most commonly used option thanks to its excellent balance of strength, ease of use and cost-effectiveness. It is also the material used in the construction of most recreational boats, making it highly compatible with the original structure.

To repair cracks, impact damage, small holes or worn areas, it is common to use chopped strand mat (MAT) or woven glass fibre fabrics together with a suitable resin system. The best reinforcement will depend on the location of the repair, the loads the area must withstand and the desired finish.

Carbon fibre can also be used in certain repairs where increased stiffness or reduced weight is required. However, it is generally more expensive and requires careful planning to fully benefit from its mechanical advantages.

In areas exposed to impacts or abrasion, aramid fabrics such as Kevlar® may also be used, as they provide excellent resistance to wear and impact damage.

In general, for most fibreglass boat repairs, glass fibre remains the most practical, economical and effective solution. The final choice will depend on the type of repair, the boat's original construction and the performance requirements of the project.