Columbia Coronado 25 Owenrs Manual page 85

6.1.6 (continued)
Chopped fiber materials include mat and other chopped rovings. Although roving
is sold as continuous strand material, it is usually chopped during use. These
materials offer non-directional strengths and are applied behind gel coated
surfaces to prevent the weave pattern of the cloth or woven roving from being
transferred to the exterior surface. Still, chopped fibers do not provide as
high a level of strength and stiffness as do the continuous fiber products.
6.1.7 Manufacture of Fiber Glass Products
Fiber glass products are manufactured by combining the basic materials
described in a suitable mold. Several techniques are used, two of which
are hand lay up and sprayup.
In hand lay up fiber glass materials (mat, woven roving and/or cloth) and
resin are placed manually in the mold. Hut, first, the mold has to be
prepared. It is cleaned thoroughly, cracks and flaws are repaired, and a
release agent (such as a wax) is applied. The proper gel coat is then
brushed or sprayed onto those mold surfaces corresponding to the external
surfaces of the finished part.
After the gel coat has cured, enough glass fiber laminates for the desired
thickness of the product axe cut to fit the mold, and the resin is prepared
with catalysts and/or promoters. Glass and resin are then added alternately
until the laminate is complete. Each layer of glass and resin is worked with
serrated or grooved rollers or squeegees to facilitate the resin's wetting of
the glass, to remove air bubbles, and to obtain the desired thickness.
The finished laminate is allowed to gel undisturbed: and then, as soon as
practicable, it is extracted from the mold and set aside to complete its
cure before subsequent finishing operations begin.
In Sprayup, a mechanized improvement on hand layup, resin and chopped fiber
glass roving are sprayed simultaneously onto the mold surface. The resulting
mass is then rolled and cured.
SECTION 6
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