Final Fairing & Finishing - WEST SYSTEM Epoxy

Figure 7 Apply the fairing compound with the
notched spreader. Control the height of the
ridges by the angle you hold the spreader.
4. Apply the fairing compound with the notched spreader (Figure 7). Hold the spreader
at a higher angle to leave deeper ridges on the lowest areas and at a lower angle to leave
shallower ridges on the higher areas. The tops of the ridges should be slightly above the
finished fair level. Allow the fairing compound to cure thoroughly.
5. Sand the ridges fair. The ridges of fairing compound are much easier to sand than solid
material.
6. Prepare the surface for bonding. Use a wire brush to rough up the exposed surface of
the fairing compound within the grooves.
7. Trowel a second layer of fairing compound over the surface to fill the grooves (Figure
8). Use a smooth-edged spreader held firmly against the surface to drag away excess
compound, leaving a smooth surface flush with the faired ridges. Mix the fairing compound
for the second layer to the same density as the first layer. Allow the fairing compound
to cure thoroughly.
8. Sand the surface smooth. It should require only minor local fairing before barrier coating
and finishing as described in the Finishing section.
Guide methods
Final Fairing 7
Figure 8 Trowel a second layer of fairing
compound over the surface to fill the grooves
after the ridges have been sanded fair.
The standard method for filling low areas is often one of trial and error. Excess fairing
material is applied, then removed and often reapplied and removed until a fair level is
reached. Skill and experience are required to accurately apply the fairing compound
and cut it away to produce a fair surface with a minimum of waste and effort. The batten
guide or template guide methods allow you to accurately fill low areas over a very
large area, even entire hulls, using a minimum of material and requiring less sanding
time.
Ridges of fairing compound are applied across the unfair surface and a batten or templates
are pressed into the ridges. When cured, the cast batten or template profiles provide
guides for the application of the remaining fairing compound. A batten laid across
the guides accurately controls the level of the fairing compound applied between the
guides, in much the same way concrete is leveled between two forms to build a sidewalk.
The number of guides required depends on the size and shape of the surface. On
flat or simple curved areas like a hard chined hull or a fin keel, one to three guides may
be enough to describe the surface. On curved surfaces, a number of closely spaced
guides may be necessary to accurately describe surface. A single guide may be placed in
an unfair area for general reference or many may be applied over an entire hull in a
regular grid pattern for more precise application.