Fiberglass is a composite material widely used in the automotive
industry, kit cars are often made from fiberglass as are many
sports cars including the Chevrolet Corvette.
Fiberglass is an incredibly versatile material and it comes in
several forms. Almost everyone has seen fiberglass insulation
and anyone who has touched it will recall the itchy feeling often
with a little rash which develops afterwards. This Is because
the minute shards of glass cut into the skin and cause irritation.
fiberglass used in the automotive industry is different from
insulation fiberglass. It usually comes in a mat, tissue or
cloth, although a chopped strand mixed with resin is often used
for large applications such as boat hulls.
with Fiberglass is an unpleasant business due to the fumes from
the resin and itchiness of the fiberglass. Whenever you are
working with fiberglass use gloves, overalls and a respirator,
take frequent breaks for fresh air if you are in a confined
space. To reduce the itching of fiberglass try not to scratch
. Instead wash the affected areas gently with cool water as
often as possible.
Gelcoats are the shiny face of fiberglass, gelcoats are what
you see on most fiberglass vehicles (which haven't been painted)
or boat hulls. Gelcoats consist of a thick gel-like resin mixed
with a colored pigment, it is the first thing laid into a mold
and therefore when the mold is removed it becomes the exterior.
Below is simple diagram showing how many fiberglass bodies are
constructed, there are other methods and this is just a common
Fiberglass tissue as the name suggests is a very thin tissue
like layer of fiberglass, it is very smooth and porous and the
tissue sits underneath the gelcoat. Tissue helps to smooth out
the inherent roughness of fiberglass matting, while also adding
Fiberglass matting makes up the bulk of any fiberglass bodied
car. Several layers are built up one on top of another until
the desired thickness and strength is achieved. This is what
you might see if you look at the inside of a fiberglass panel.
Fiberglass cloth is strong and is often used where it may be
visible and therefore aesthetics are important. One of the downsides
of fiberglass cloth is that because the strands are neatly woven
the layers do not intermesh like they do with the disorganised
and loose strands on the fiberglass mat. Therefore the layers
of cloth sit on top of one another, rather than meshing together
like the fiberglass mat.
Resin and Hardener
Without resin the fiberglass itself would be useless for building
anything requiring rigidity. Resin is mixed with a catalyst
before application to the fiberglass. The drying process involves
a chemical reaction which has several variables including, the
amount of catalyst, temperature, humidity, and any water present
in the fiberglass resin (water shouldn't be there!).
As a personal example I once added sand to fiberglass resin
to achieve a rough texture needed for this particular application.
The sand was ever so slightly damp. The resin without sand dried
quickly and without event, the resin with sand in took several
days to fully harden.
When the chemical reaction between the catalyst and fiberglass
resin takes place heat is produced, depending on the thickness
of the resin the temperatures can get quite hot. Enough to melt
plastic in extreme cases.
The results which can be achieved with fiberglass are quite
impressive. Its properties allow anyone to make an exotic bodyshell
for a car. Once fully hardened and sealed with resin or a gelcoat
fiberglass is waterproof, relatively light weight and when done
properly it is extremely strong. It is reasonably inexpensive
when compared to the alternatives, in short it is an ideal material
for the automotive field.