This is a basic overview on the fibreglass coating
which is used on many home built boats. I have used
pictures from stevenson's projects website. Once the surface
of the boat is prepared a cloth is laid over the
area and smoothed.
This cloth is generally fibreglass although you can
get other materials such as kevlar. After that the Fibreglass Resin is
allied.
There are three types of fibreglass resin you
can use. They are;
POLYESTER-
This was a very popular coating with boatbuilders for quite a while.
It is cheap and easy to use. DO NOT USE IT. Polyester allows water to pass
through it. This water becomes trapped between the fibreglass coating and the wood.
This water will cause wood rot, and the fibreglass coating to delaminate.
VINYLESTER-
This coating is the one recommended by the Stevenson's in
the weekender video. It is almost identical to Epoxy except it is
more UV resistant. It is a commercial product however, and can
be difficult for a home boatbuilder to get.
EPOXY-
Epoxy is expensive, but is used by most home
boatbuilders. It is less UV resistant but you
will be painting over it anyway. Be carefull with
epoxy. Many people have alergic reactions. Wear a mask and gloves, and
use it in a well ventilated area.
NOTES:
COVER EVERYTHING OR NOT
Many people glass the boat on the bottum and then glass
or epoxy everywhere else. There is quite a dispute going
on concerning this practice. Here are the two sides.
The people who cover all surfaces with epoxy state that it protects the entire wood
surface. The people who are against this practice however state that no
epoxy job no matter how carefull is perfect. There will be small even microscopic holes
in the epoxy surface where water can get through. Once socked into the wood the water
can not dry out of the wood because it is sealed in epoxy. They suggest that it is
better to only put the epoxy on the wood where it is necessary. For example if you
epoxy the outside of the boat and not the inside any moisture soaked into the
wood from the outside can dry out into the inside through the uncoated side. I am
assuming that paint will allow water vapour through. I have not
made up my mind on which side is right but due to the dispute and the cost of epoxy I will
only be coating my boat on the outer hull and deck with tape on the keel bottum and seams inside.
