Fibreglass is a great light-weight material, which can be used to make all kinds of different things. Little watercraft are made from fibreglass, as well as water tanks, some hand luggage, swimming pools and other things that have to be strong yet very light. A lot of cars used to be made from fibreglass, but this material fell out of favour of car manufacturers. Why?
Fibreglass is really a great material to make cars from. It is light, quite tough, not very expensive on its own (more about that later) and doesn’t rust. In fact, it was a material of choice for many historic sports cars – Lotus, TVR, Rochdale, Morgan, AC, Daimler and many other manufacturers of British sports cars used fibreglass. Even the American icon Chevrolet Corvette is traditionally made from fibreglass, but this material is not exclusively reserved to expensive sports cars. The famous three-wheeler Reliant Robin also enjoyed the many benefits of fibreglass body. And there really are a lot of benefits.
Smaller manufacturers loved fibreglass because tooling was not that expensive either. You only need some forms to lay plies of fibreglass into and they lasted for many years. Meanwhile steal stamping tooling wears out quite quickly and is very expensive. The more intricate the part is, the quicker the tool is going to go bad. And so, it was much easier to use fibreglass for more curvy parts of the car. It allowed for more design freedom and generally a lighter car.
Nowadays fibreglass cars are quite rare in the automotive industry. Sure, Lotus still makes them and some Corvette body parts are made from fibreglass, but this material is definitely not as popular as it used to be. There are several reasons. First of all, due to current safety standards, fibreglass is not sufficient anymore as a material for structural parts. This means that fibreglass panels can only be mounted on a stronger frame, which reduced the ratio of fibreglass to steel in a car. For example, most of the old Lotus Elan was made from fibreglass – only its backbone chassis was steel. This means that new fibreglass cars would not enjoy full benefits of this lightweight material.
Then there is a matter of price. Fibreglass by itself is not that expensive. The problem is that it requires a lot of manual labour and time. Someone has to apply the different layers of fibreglass and then they have to wait for them to dry in the mould. Turnover of tools is just not good enough for today’s standards and manual labour is really costly.
Finally, modern metal-forming techniques allow for intricate steel parts to be made, which further reduces the benefits of fibreglass. It is flammable too, which has to be taken into consideration. And so it is not as common as it used to be. The good news is that the old fibreglass cars are still around as they don’t rust (fibreglass may crack or shrink though) so it is up to you to find and restore one.