9
Preparing a Cored Fiberglass Hull
The core (wood or foam) must be cut and sealed carefully. The core must be protected from water
seepage, and we recommend that the hull be reinforced to prevent it from crushing under the locking
nut which would allow the housing to become loose. If unsure, please consult your local OceanLED
representative.
TIP
: Always wear safety goggles and a dust mask.
1.
Drill a 3mm / 1/8" pilot hole perpendicular to the inside of the hull. If there is a rib, strut, or other
hull irregularity near the selected mounting location, this will need to be taken into account in
the planning phase and the location adjusted accordingly, or the obstruction safely removed or
modified. If the pilot hole is drilled in the wrong location, drill a second hole in a better location and
repair first pilot hole.
2.
Using a 1" sized hole saw, cut a hole from outside the hull through the outer skin only. Be sure to
hold the drill plumb, so the hole will be perpendicular to the angle of the hull.
TIP
: Be aware that to seal the core, you will need to reinforce the core by replacing the soft core material
with hard epoxy. Reinforcing the core will prevent the hull from crushing when the unit is tightened down
and prevent the unit from releasing the seal pressure due to core compaction.
3.
The core material can be very soft. Apply only light pressure to the hole saw after cutting through
the outer skin to cut through the material. Once you have cut through the core material, you will
need to apply more pressure to cut through the liner material on the inside of the hull.
4.
Remove the plug of core material so the core of the hull is fully exposed. Using a heavy grit
sandpaper, sand and clean the inner skin, core, and the outer skin around the hole to remove
fiberglass. Then using a Dremel tool, carefully remove around ¾” of the core material from inside
the outer and inner layers of hull. Be careful at this point to not damage the outer hull layers. This
process should leave a ¾” recess.
TIP
: Completely seal the hull to prevent water seepage into the core. Allow enough preparation time
for several layers of epoxy to completely dry. Remember – environmental conditions can accelerate or
decelerate curing times which also varies on type of epoxy used. Consult epoxy directions and test cure
time before procedure.
5.
Using any type of hard epoxy, generously coat the inside core material with the epoxy, making sure
to evenly coat the inside surfaces.
6.
When dry, gently sand and clean the area around the hole, inside and outside, to remove excess
epoxy buildup and also to remove any previous bottom paint to ensure that the sealant will adhere
properly to the hull. If there is any petroleum residue inside the hull, remove it with acetone before
sanding.
OceanLED INSTALL / AMPHIBIANS / 053014 / v4.2
