Firstly you will need the basic elements ? these are the fibreglass matting and the resin as well as the chemical catalyst. Follow the instruction when applying the resin to the matting, but usually this depends on the amount of humidity in the atmosphere for the fibreglass to gel or set properly. Do not attempt to work with fibreglass in a very cold environment as the setting process could take a very long time. There are two basic methods of working in this medium. One can build up a sculpture by directly modelling the fibreglass onto an armature, or one can cast a sculpture made in another medium into fibreglass. The second casting method is by far the most common and this is the method that will be followed here.
Make sure that you have a clear working space. Have the fibreglass matting cut into squares of about 3 by 3 inches in size. Make sure that you have your resin handy and thirdly, the catalyst that will initiate the chemical reaction and form the hard medium. You should already have a plaster mould of a sculpture that you have completed, ready for casting. Finally, a few ordinary house paintbrushes, old cloth and a bottle of acetone should be handy.
Preparing the mould for casting.
We will presume that you have a plaster mould of your sculpture. There are different techniques for working with moulds made from different materials, but plaster is the most common material used for making moulds. The reason for preparing the mould is to ensure that the fibreglass can easily be separated form the plaster after it has set. One can buy a number of industrial separating liquids made especially for this process, but the cheapest, and most effective way of preparing the mould is by using liquid wax. Liquid wax can be bought at any supermarket. Apply three coats of liquid wax to the surface of the mould, waiting for each to dry before applying the next. Make sure that you do not use this brush for the application of the resin the next stages.
Applying the first coat of resin
Once the plaster mould is prepared, take a tin can or any other steel container and mix an amount of resin that will cover the interior of the mould. This is the first coat and should be fairly thick. You can buy a special form of resin called Gel Coat which has a gel like consistency and which will not fall back form corners or curves in the mould. Before applying your first coat, make sure that you add the catalyst to the resin. The amount of catalyst depends on the manufacturers instructions. Mix the catalyst well into the resin and start applying the resin to the interior of the mould, being careful to cover every inch of the surface.
Leave this first layer to begin the setting process. Resin, which has been exposed to its catalyst, will dry very quickly and will harden any brush you are using beyond repair. This is where the acetone comes in. Take another tin can and fill it with acetone and wash all brushes that come into contact with catalysed resin in this liquid.
Once the resin has begun hardening then you can apply your first layer of chopped glass matting. Take the squares that you have cut and place them over the surface of the mould. Then dip a brush into the resin/catalyst mixture and stipple the layers of matting into the resin. The process called stippling simply meant to force the matting into the resin with the pointed ends of the brush, usually by jabbing down into the mould. The point is that the glass matting must be saturated and have a close contact with the resin, as it is the combination of these two elements which makes the strong fibreglass.
Continue this process until you have at least five layers of resin and glass matting. It is advisable to use at least 10 layers for larger sculptures.
Leave the cast to dry for at least one day to ensure that the fibreglass has properly cured or has set completely. Please note that it may take a longer period of time for the resin to cure if the weather conditions are cold and humid.
The final stages
Once the cast has cured, you can remove the plaster mould. This is usually accomplished by chipping away at the plaster exterior until the fibreglass cast is revealed. Be patient with this process, as large sculptures may take some time when removing the plaster mould.
Once all the plaster is removed, one is left with the final product- the fibreglass sculpture. Sanding or angle grinding may further refine this. The finished sculpture will also accept acrylic or oil paint as a finish.
how east does that sound..and cheap! plus i will have the wood mould to make into a hollow wood body version, and if both works perhaps ill sell the wood body! any takers lol