Swimming Pool Repairs & Renovations
Generally pools are hand laid using chopped strand mat fibreglass. This ensures that an even minimum thickness is achieved. This is usually 450g/m2. On some fibreglass pools this may be doubled to 900g/m2. Once applied this now becomes the structural laminate and this gives the filler and gel coats their back bone to last up to 20 years of service.
After the initial fibreglass laminate is laid down a filler coat is then applied. The filler coat is specifically designed to be applied and then sanded down smooth so that the fibre pattern of the fibreglass does not show through the final coat.
This is not generally considered part of the structural integrity of the lining as it is carrying high loads of filler.
The final coat is the finish or gel coat. This is considered the decorative finish and its main function is to enhance the pool's appearance. The gel coat is not considered structural as water does migrate through it. The main barrier is the initial structural fibreglass laminate underneath. This final gel coat is specifically developed for full immersion in pools so as not to oxidize or fade and as such is more expensive than other gel coats used. Normal gel coats cannot withstand chemical attack as well as our specifically formulated pool gel coats.
The resins used in lining pools have greatly improved over the years. It is important to understand that there are different resins and not all are suited to full emersion under water with oxidizing agents like chlorine present, sometimes in quite high concentrations.
For example, the resins that are used in building a bus seat would not be suitable for lining a pool. Some of the resins we use are strictly pool related and are not generally used anywhere else except in some industrial applications.
All fibreglass laminates (even carbon fibre or kevlar) are engineered by weight, usually in grams per square meter (gr/m2). They are never engineered by layers. Using layers without specifying weight could be misleading in determining quantity of material used and its ultimate life.
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LAYERS vs WEIGHT
It is not possible to just sand the surface and apply a new gel coat. The materials we work with are thermo set plastics, not paint. They require a molecular bond or cross linking at the molecular level for adhesion. Therefore a new complete fibreglass laminate needs to be applied in this situation, otherwise it will flake again.
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