PRACTICAL
Foam suitable for boatbuilding is available
from specialist glassfibre suppliers for
around £30-40 for a 4ftx4ft sheet. Start
with a dry fit of the new material. It doesn’t
need to be a perfect glove-like fit, though
the thickness should match that of the
original core, and if you leave too many
gaps they will need to be filled by a
greater volume of expensive epoxy.
Equally, each section doesn’t need to be
in a single sheet – indeed it’s probably
easier to fit if it’s not. It’s also important to
make sure everything is properly dry
before you start the laminating stage.
This is the first stage of gluing the
structure back together. Other than for
very small panels this will take a greater
volume of filler than you imagine. It needs
to be mixed to a consistency at which it’s
almost able to stand in peaks like beaten
egg whites or meringue.
Andy mixed a large quantity in a big
container, before trowelling it onto the
deck to spread it out as quickly as
possible. It’s worth emphasising that it’s
important to work fast at this stage. The
epoxy will have a working life of an hour
or so once it’s spread out, which allows
the heat released during the curing
process to escape, but if left in volume in
a large mixing container it will create an
Any epoxy that has been squeezed out of
the edges in the last stage of the process
can be trowelled towards the centre of the
foam, and more epoxy filler added to
provide enough to bed the top layer of
laminate. Again press down firmly from
the centre and remove the excess that’s
squeezed out at the edges. To ensure a
good bond it’s worth applying an even
spread of weight across the deck – we
used bags filled with sand from the beach
next to the boatyard to provide an even
pressure while the epoxy cured.
(^12)
Epoxy is spread on the foam ready
for the outer skin to be replaced.^13
Glue should squeeze from the edges
and this can then be tidied up.
14
Bags of sand were ideal for
applying an even pressure across
the deck laminate while the glue cured.
(^9)
The area clean and dry ready for the
new foam to be glued in place.^10
Cutting to size and dry fitting the
new foam panels.
11
Spread the epoxy quickly and
liberally then fit the foam, ensuring
glue is squeezed out at the edges.
Step
by
step
Cut and shape new foam
Bed new foam on epoxy/silica mix
Glue the old top-layer of laminate back in place
exothermic reaction, getting hotter
and hotter in a handful of minutes
and set the epoxy prematurely. The
key is to start by putting large
dollops onto each area of deck, then
roughly spread these out as quickly
as possible, before finally checking
the detail at the edges and corners.
Make sure the whole base is well
covered, with plenty in the recesses
around the edges – to be sure there are
no voids you’ll need to see at least a bit of
excess being squeezed out everywhere
when you place the foam. With epoxy
spread, position the foam, pressing it
down in the centre of each panel, then out
towards the sides.