Wooden Boat Restoration Repair - WEST SYSTEM Epoxy

6.3 Casting epoxy bases for hardware
Installing Hardware 45
Occasionally, fittings must be set at specific angles to the hull or deck surfaces.
Downrigger bases, lifeline stanchions, winches and turning blocks are all good
examples. Traditionally, hand-carved, wedge-shaped shims have been used to achieve
the proper angles with such fittings. Unfortunately, wooden shims require a great deal
of time and carpentry skill. Hardware casting can save time and is easy to do; more
importantly, it can result in a stronger, waterproof base. Cast the hardware at an angle
to the surface as follows:
1. Prepare the bonding surfaces. Clean the substrate and hardware bonding surfaces with
solvent to remove any contaminants. Sand the deck with 50-grit sandpaper. Apply a
release agent, such as an automobile wax or a non-stick cooking spray, to the base of
the hardware.
2. Position the hardware. Mark the outline of the hardware and shim it to its desired
angle. Mark the shim locations. Often one edge of the fitting will rest on the deck and
become the zero point for the required angle.
3. Wet out the substrate (deck) surface with resin/hardener mixture except for the shim
locations.
4. Cast epoxy supports under the hardware (Figure 6-3a). Prepare a mixture of
resin/hardener/404 High-Density filler (peanut butter consistency). Use the mixing
stick to place three portions of the mixture within the hardware outline, evenly spaced
around the perimeter. Use enough of the mixture and pile the mixture high enough to
contact the base of the hardware when it is shimmed in its proper position. When
cured, the epoxy supports will take the place of the temporary shims. Set the fitting in
place with the temporary shims holding the hardware at the proper height and angle.
The bottom of the hardware should contact all three epoxy supports. Allow the epoxy
supports to cure thoroughly.
5. Tap the hardware with a mallet to break it loose and remove the temporary shims.
Mask off the area around the fitting with duct tape and plastic in case of accidental
epoxy spills.
6. Prepare the deck and hardware for casting the base. Wash and sand the cured epoxy in
the deck base area. Reapply mold release to the hardware base. At this time, mask off
areas of the hardware that you don’t want to come in contact with the epoxy. You may
also find it helpful to place small pieces of tape over the holes in the hardware item to
prevent the epoxy mixture from oozing up through them when the piece is
repositioned.
7. Apply enough thickened epoxy/404 (peanut butter consistency) to fill the entire base
area. If the base to be cast is more than ½" (12mm) thick, you may want to use 206 Slow
Hardener to reduce the possibility of exothermic heat buildup during the curing
process. Build up the mixture slightly taller than the base supports, roughly forming
the shape of the base. Fill all voids around the epoxy supports.
8. Reset the hardware in its proper location. Slowly press it into the proper position on
top of the cast epoxy supports. Allow excess epoxy mixture to squeeze out of the gap
between the base of the hardware and the deck. Sculpt the squeezed out mixture into
the desired shape (Figure 6-3b). A standard fillet works well in this situation (Section
8.4.3). Add extra mixture if necessary for shaping or to fill any voids. Remove any
excess before it cures. Allow the epoxy to cure thoroughly.
9. Tap the hardware with a mallet to remove it from the base. Clean the bottom of the
hardware and the top of the cast base with solvent to remove the mold release. Sand
both bonding surfaces with 50-grit paper.
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