Practical Boat Owner – May 2018

(sharon) #1

64 Practical Boat Owner t http://www.pbo.co.uk


PRACTICAL


More complex shapes: making a double-ended canoe


REINFORCEMENTS


Wax (x3)
600g/m biaxial cloth
600g/m biaxial cloth
400g/m reinforcements
4x across
1x bow
1x stern
2x gunwales
Peel ply
Re-mesh
(epoxy transport mesh
with release sheet combined)

2
2
2

1 2 3 4 5 6

Canoe infusion
Layers under the bag
(in order of application)

Each layer is cut to shape,
but comes off the roll rectangular

65

4

4

4

4

4

2

1

3

1


Confi dent that we had learnt the
basics, it was time to transfer our
new-found epoxy vacuum infusion
knowledge into making a double-ended
canoe, a Gougeon 12.3. The process
followed much the same route as making
our demonstration clipboard, except this
time there would be no gelcoat stage, and


no hand-brushed wetting out. Instead, the
infusion epoxy would be piped in and
form both the inner and outer fi nish. On
production models, a manufacturer would
probably choose to brush in an exterior
gelcoat fi rst for aesthetic reasons. Ours
would be simply be rubbed down and
spray-painted when fi nished.

2


The canoe mould is prepared with
three coats of release wax, each one
polished hard to partly melt and spread
each layer thinly.


3


The fi rst of a total of two layers of
600g/m^2 biaxial cloth is rolled out
over the hull, ensuring there is overlap at
the edges for trimming.

4


The glassfi bre cloth is lifted up and
draped into the hull mould. Each
end is then folded in and cut
symmetrically to form the stem and stern.


5


The edges are carefully trimmed to
about 15mm from the outside of the
mould. This is to allow the vacuum bag
sealant tape to attach to the fl ange.

1


Extra lengths of 100mm 450g/m^2
reinforcing cloth are placed in the
bow and stern, and at regular intervals
across the hull, and taped into place.

2


Reinforcements across the hull are
cut and slightly overlapped in the
middle to avoid distortion – they will move
slightly under vacuum.

3


Another layer of 100mm reinforcing
tape is added along the length of
each gunwale, creating a complete rib
cage of extra strength.

(Colours for guidance only)
Free download pdf