About Fiberglass

Fibreglass was developed in the late 1940s. It was the first modern composite and is still the most common. It makes up about 65 %of all the composite materials produced today. GRP or "glass fibre reinforced plastic" consists of two distinct materials, a fibres of glass (ceramic), which is the reinforcement and a polymer resin called polyester, which serves as the matrix. The polyester resin polymer alone is brittle and has a low strength but when fibres of glass are embedded in the polymer it becomes strong, tough, resilient and flexible. It becomes an ideal material to make boat hulls, swimming pool linings, car bodies, roofing and furniture. The other advantage of GRP is that it is very light. It is said to have a very good strength to weight ratio. A resilient material is one that returns to its original shape after bending, twisting, stretching, compression. A tough material is one that has the ability to withstand sudden blows or shocks without breaking. This material can also be bent without cracking.

An intricate process, there are essentially seven stages in the manufacture or assembly of fibreglass products.

  1. I. Design Department

    Here a specially trained designer designs models that are aesthetically appealing. He is an artist endowed with sculptural talent.

  2. II. a) Wooden Model

    At this stage, carpenters erect a wooden model which is a complete replica of the proposed product under the keen supervision of the designer. This wooden model is in most cases temporary and dismantled after use.

  3. II. b) Fibre glass Model

    This model is preferable to II (a) in that it is more refined and is intended to be a permanent replica of the product for future use. However in case of unavailability the wooden model maybe used.

  4. III. Moulding

    A moulding of either 11(a) or 11(b) is undertaken which is painted black to differentiate it from the final product to be laminated in or on it depending on it's design at IV.

  5. IV. Laminating

    This is the most intricate part. The moulding (III), is polished by use of wax so as to prevent the lamination from sticking to it. The wax forms a cushion whereby the laminate rests and remains independent of the moulding. A paste of the required colour is then poured over the wax which is mixed with a hardener and a catalyst to speed up the process of solidifying.

    Then fibre glass matt is placed whereby the desired thickness determines the number of matts to be used; this is done in conjunction with the application of resin which acts as the bonding agent.

  6. V. The Drying Stage

    Immediately IV is over, a hardener and a catalyst is added to speed up the drying process. However this is a sensitive stage in that it is essentially controlled by the given Iocational environmental conditions since most firms prefer their fibre glass production undertaken in an open atmosphere rather than in simulated situations which are quite exorbitant.

    If the weather is hot it dries out quickly, if on the contrary it is cold, it may take longer thereby delaying delivery of products to clients. On normal average weather conditions the process may take two to three days and by that time the chemicals have already dried and the curing process is complete , meaning that no more cracks should appear.

  7. VI. The Trimming Department

    After V; a moulding releasing agent is used to separate the moulding from the laminate (final product) and unde-sired protrusions are trimmed off. The product is then ground to give it a smooth finish. If there are any cracks due to contractions and expansions in response to weathering, a filler is used to repair and, in the case of car bodies or water tanks etc where there is a visible rough surface, it is not only ground but also a layer of paste is applied to smoothen it mixed with monomer to make it non-sticky [the resin is always sticky.] If there are un-coloured spots, they are painted to give a uniform elegant finish.

  8. VII. To The User

    The end product is then delivered to the client and in case of a car body part, it is fixed to the car and sent back to the owner.


It takes a plethora of different chemicals, almost all of which are imported, to complete this elaborate task of fibre glass production; e.g. unsaturated polyester resins, hardeners and accelerators, titanium dioxide, cab-o-sil, talcum powder, oxytol, chlorine-but syn-resin is locally manufactured.

Read more about What you need to know about Fiberglass by www.sairaj.com

Fiberglass is a composite material widely used in the automotive industry, kit cars are often made from fiberglass as are many sports cars including the Chevrolet Corvette. Fiberglass is an incredibly versatile material and it comes in several forms. Almost everyone has seen fiberglass insulation and anyone who has touched it will recall the itchy feeling often with a little rash which develops afterwards. This Is because the minute shards of glass cut into the skin and cause irritation. The fiberglass used in the automotive industry is different from insulation fiberglass. It usually comes in a mat, tissue or cloth, although a chopped strand mixed with resin is often used for large applications such as boat hulls.

Fibreglass is a composite material system consisting of fibre reinforcement, plastic resin and additives, combined and processed to meet specific functional performance and manufacturing criteria for a finished product or part. By selecting the right combination of resin and fibres, the designer can create a product or part that meets the most demanding of product specifications.

FRP is short for Fibre Reinforced Plastic and is the most widely used abbreviation for fibreglass. Sometimes FRP is used to mean Fibre Reinforced Polyester, the most commonly used plastic resin. Sometimes GRP is used and is the abbreviation for Glass Reinforced Plastic, this being the most common reinforcement used. The terms are all interchangeable.

The unique properties of Fibreglass make it suitable for a wide range of product applications, and also offer advantages that are not found in more conventional constructional materials!

  • Design freedom

    High degrees of flexibility and the practical uses of Fibreglass are virtually endless, limited only by your imagination. Fibreglass opened up many new avenues for creative designers, its unique physical properties allow it to be easily tooled, moulded and manufactured to meet almost any specification, because there are few constraints on size, shape, colour or finish, this can deliver great styling and appearance whilst being cost effective, and its this design freedom which is the hallmark of composite achievement.

  • Affordability

    This design freedom and the easiness to mould make Fibreglass an economical alternative for the manufacture of any component or finished product in any quantity.

  • Versatility

    The lightweight strength of Fibreglass has always made it a popular choice for designers and manufacturers alike, Fibreglass offers distinct advantages for a wide range of products, its reduced weight and maintenance make it attractive on architectural projects, and more industries are discovering the benefits of its versatility, these industries include, construction, leisure, marine, automotive, aerospace, transport, ministry of defence, and more !

  • Strength & durability

    High strength to weight ratio and high flexural strength make Fibreglass an attractive lightweight material, additional reinforcement can be added in specific locations to build in extra strength where load and stress points require it. When used for external applications, Fibreglass can offer a high resistance to environmental extremes, so pound for pound Fibreglass components can provide a better performance over other construction materials!

  • Appearance

    Fibreglass components are gel-coated in their moulds with a choice of flat, semi-gloss or high gloss colour eliminating the need for painting. In highly corrosive environments gel-coats are much more durable than most paints. Fibreglass products can be manufactured in numerous finishes, textures, and colours, so various surface appearances can be achieved in the mould.

  • Moulded look

    With sheet steel or wood, you get a plain component; Fibreglass components have a sleek contour and a superior moulded appearance complete with required colour.

  • Corrosion – environmentally tough

    Fibreglass is non-corrosive and has a much longer life expectancy when compared to a variety of other construction materials, in highly corrosive environments; Fibreglass is the perfect choice over metal, wood, or plastic. A popular choice where exposure to harsh environments is a concern, fibreglass can provide resistance to ultra violet light, extreme temperatures, salt air, and a variety of chemicals, because Fibreglass is chemically inert and corrosion-resistant it offers an economical alternative to stainless steel.

  • Sound deadening

    Fibreglass provides superior acoustical properties when compared to plastic or metal, various types of sound deadening material can be laminated in between high strength layers of Fibreglass matt to achieve the preferred level of sound deadening. Fibreglass exhibits a great deal of dimensional stability and the least amount of expansion and / or contraction when compared to other material.

  • Durability

    Fibreglass structures have an exceedingly long life span, coupled with low maintenance requirements; the longevity of fibreglass is a benefit in critical applications, in a half-century of composite development, well designed fibreglass structures have yet to wear out.

  • Low maintenance

    Fibreglass components require very little or no maintenance as they do not rust, rot, or fall to pieces, so if you are tired of costly maintenance associated with repairing or replacing expensive components you now have the answer, Sai Raj Ltd.

Should you have an enquiry concerning GRP (glass reinforced plastic) composite and its suitability for your project or product, please contact us to discuss your requirements further…


From the pictures throughout our website you will appreciate the diversity of the components we are able to manufacture and supply.

We can manufacture Mouldings from various material combinations to suit the desired application, so whether you require fire retardant, chemical resistant, or Mouldings that can withstand environmental extremes, we are confident that we can develop a comprehensive and cost effective solution to meet your exact requirements.

  • Signage, Signs, shop interiors & kiosks
  • Architectural, fascias & cladding, interior/exterior detail
  • Automotive, wind deflectors, high tops, body kits
  • Aviation, cowlings, wheel spats, components
  • Communications, mobile phone mast enclosures & radomes
  • Construction, form work, lift shaft liners
  • Engineering, covers, guards, housings, enclosures
  • Exhibition, components, stands, themed pieces
  • Hygiene, shower trays & cubicles, baths
  • Leisure, theme park rides, flumes & slides
  • Marine, boat hulls &, associated components
  • Specialist applications, lining, fabrications & prototypes
  • Transportation, seats, covers, bodywork
  • And much more!