changing hardeners or by cooling or heating the resin.
of materials. Although better adhesive properties are
There are many types of room temperature hardeners
generally claimed for epoxies, especially when heat is
from which to choose. Users are cautioned that room
applied to achieve a higher strength bond, they are
temperature hardeners are alkaline in nature, so they
more costly than polyesters. Like the polyesters,
should be handled with care. Rubber gloves and eye
epoxies are available in a variety of viscosities and
protection are recommended when you are handling
with a wide range of other characteristics.
epoxy resin and hardener. Always wash the skin
Epoxy resins are activated for room temperature
immediately after any contact with the hardener.
cures by the addition of a recommended amount of a
specific room temperature hardener. However, unlike
be varied to change the cure time, since any change in
The three types of repair patches applied to
concentration will adversely affect the other
reinforced plastic laminate are shown in figure 4-7.
properties. Cure conditions can be varied only by
Figure 4-7.--Types of patches applied to reinforced plastic boats.