Basic Design Tips The list of articles that you can make using composites is almost endless, but to name a few - boats, canoes, chess sets, showers, industrial piping, underground petrol tanks, vehicle repairs, garden ponds, replica armour. You name it, fibreglass can often do it. With a few simple tools quite large projects can be tackled - The only resriction is your vision! There are a multitude of fibreglass/composite products on the market, made from a variety of methods. Invariably they are made in a mould, so it seems obvious that the number one consideration is that your final product must be removable from your mould. Many may get a shock at the cost estimate to make (for example) a light weight front end for their favourite chariot, but the steps are as follows:- 1. Make a Plug - the exact replica of the article you want, made from customwood, ply, bog, high density foams, or whatever may be cost effective for your particular project. The plug must be finished to the quality you want your finished product to emerge from the mould as. Everything on the plug is reproduced exactly, apart from sanding out blemishes and defects either on the plug or mould, these will appear on the article. 2. Make a Mould - the mirror image of the plug, taken off the plug. The plug must be prepared with release agent to prevent sticking of the fibreglass laminate laid over it. The construction of the mould will vary according to the number of units expected from it. One-offs can be very light. High production moulds will obviously be very solid and well supported, possibly by timber or steel frames. 3. Make the Article - your final product constructed according to final use and the quality dependant on the effort gone into the previous two steps. It costs no more to make a product with a first class finish, than one with a terrible finish. The extra costs are in the previous two steps. As an indication, plug and mould costs are multiples of the final article cost. For a moderately complex article requiring a one piece mould, and approximately 50 units required these could be as follows: Some points to consider to make sure you get what you want at a cost effective price: Properties - It is not cost effective to use composites in conventional applications against conventional materials, unless you are exploiting its advantages. If you are going to use it, get the most out of it! Basic composite laminates, while strong, are not stiff. Do not confuse these two properties. For example a 4mm thick strip of fibreglass may bend twice as much as a strip of 4mm ply for the same load, but it may take 4 times the load before it breaks! (These are indicative figures only)