1. Mouldings are made in moulds which are prepared by polishing to high gloss after application of a release wax. For new moulds it is advisable to use PVA release agent to ensure avoidance of stick-ups.
2. Gel-coats are highly thixotropic materials, normally pigmented, which are applied to the mould by brush or spray after addition of MEKP. To ensure a good cure the film thickness should be at least 0.5mm and the MEKP level 2%.
   The gel-coat must cure sufficiently before applying the reinforced laminate. Curing normally takes at least 2 hours but this will depend on conditions such as temperature, gel-time, mould profile and film thickness. No transfer of colour from the gel-coat when touched is a good guide to readiness for reinforcement.
3. Fibre reinforcement is used to give the laminate strength. The most common is glass fibre which is available in a variety of forms. Other fibres include carbon fibre and aramid fibre (Kevlar) which can be used to provide special properties.
   The most common forms of glass fibre are chopped strand mat, glass cloth, woven roving, surfacing tissue and gun rovings which are chopped and sprayed along with resin directly onto the moulding. In all cases the laminate must be consolidated to remove trapped air. This is done by rolling with laminating rollers.
   The quantity of resin required will be governed by the type of reinforcement used. For instance, chopped strand mat needs a resin/glass weight ratio of about 2/1 while woven roving needs about 1/1.
   Laminating resins are normally used with about 1% MEKP. Some resins contain wax to give a well-cured surface If these are used in constructing mouldings where the resin is allowed "each layer is allowed to cure before relaminating"to cure between layers? then the surface should be abraded before applying another layer so a good mechanical bond is obtained.
4. When the resin has gelled but before it cures hard, it is common to trim the periphery of the moulding with a sharp knife to remove excess material and prevent the necessity to grind back later.
5. If a flowcoat is used to improve the appearance of the back surface of the moulding, this would normally be applied before the moulding is extracted from the mould.
6. A variety of methods can be used to extract mouldings from moulds. These include the used of wedges, levers, suction devices and compressed air. Always take care to avoid damaging the mould surface.

Associated Topics and Materials.

• Fillers such as talc (non-scented), calcium carbonate or microspheres can be used with laminating resins to make putty compounds but better results are likely to be obtained if specialist putties are used, as the resins used in them are more flexible and give better adhesion.
• Solvents - acetone is the most common solvent used in fibreglass operations to clean rollers, brushes and other equipment. It is very highly flammable and must never be mixed with MEKP.
• Epoxy resins are more flexible than polyesters and give better adhesion to most clean abraded substrates. They are often used with glass cloth in sheathing hulls of wooden boats.
• Temperature - in all operations using both these types of resins the temperature will be very important in affecting the rate of gel and cure. Avoid direct sunlight as this may cause rapid gelation and excessive exotherm. If conditions are too cold, long gel times and poor cure will result. Both of these may result in distortion of the moulding.
• Health & Safety: - The resins, solvents and initiator (MEKP) used in fibreglassing operations are all potentially hazardous materials. Care must be taken to use the materials safely, in well ventilated areas, avoiding direct contact and using appropriate protective equipment such as overalls, gloves, eye protection and respirator as necessary. Technical Data Sheets and Material Safety Date Sheets for all materials should be read before using the materials.