The Gougeon Brothers on Boat Construction - WEST SYSTEM Epoxy

Chapter 14 – Hardware Bonding 141
Figure 14-13 Apply epoxy to the bonding surface.
to indicate 100% contact, but not so much that large
globs squeeze out when you set the item in place.
After applying epoxy to the surfaces, put the fitting
back in position and coat and install all the fasteners,
tightening them until everything is snug (see Figure 14-
15). Clean away any epoxy which squeezes out as the
item is bedded down. Use a putty knife or narrow
plastic spreader to remove most of the excess and paper
towels or rags to clean up some of the thinner epoxy.
We use solvent with paper towel on unpainted surfaces
when this is necessary for a thorough job. Dry cheese-
Figure 14-14 Wet sand the epoxy into the bonding surface.
Epoxy squeeze out
Backing plate on
thinner substrate
Figure 14-15 Tighten fasteners or increase clamping
pressure until a small amount of epoxy squeezes from
the joint.
cloth works well for removing the last uncured epoxy
residue. If a lot of epoxy squeezes out, you have applied
more than was needed, either to the hardware surface or
to an oversize hole. Try reducing the quantity on the
next item until a small but healthy amount of epoxy
squeezes out.
Casting Hardware in Place
Sometimes, fittings must be set at specific angles to the
hull surface to which they are attached. Winches, for
example, are angled to maintain a proper lead. Lifeline
bases, turning blocks, and engine mounts often must be
arranged in a manner that doesn’t permit them to
sit flat against a surface. Wedge-shaped wood bases
and shims are usually used to support these items,
but making them takes a great deal of time and skill,
especially on surfaces with a lot of camber. With the
hardware casting process, you can save a lot of time
and end up with superior results.
To begin casting, clean the wood/epoxy surface and set
the fitting in position, resting it on three points. One of
these points is generally the lower end of the item itself
and the other two are small, temporary wood props—
wedges work well—cut to the right height. When you
have the hardware exactly where you want it, load a
syringe with about a 50%-50% mixture of 404 High-
Density and 406 Colloidal Silica Fillers and epoxy.
Inject the thickened epoxy within the perimeter of