Vetus BOWA0361 Manuel D'installation page 19

3.5 Installation of the thrust tunnel
• Drill 2 holes in the hull, where the
centreline of the thrust tunnel will
be, in accordance with the diameter
of the marking tool.
• Pass the marking tool (home-made)
through both pre-drilled holes and
mark the outside diameter of the
thrust-tunnel on the hull.
D [mm] (inches)
Steel GRP Aluminium
133 136
(5 9 / ") (5 23 / ") (5
32 64
• Dependent on the vessel's construc-
tion material, cut out the holes by
means of a jigsaw or an oxy-acety-
lene cutter.
• Install the thrust-tunnel.
Polyester thrust tunnel:
Resin: The resin used for the polyester thrust tunnel is Isophtalic
polyester resin (Norpol Pl 2857).
Pre-treatment: The outside of the tunnel must be roughened.
Remove all of the top surface down to the glass-fibre. Use a
grinding disc for this.
Important: After the tunnel been sawn to length, treat the end of
the tube with resin. This will prevent water seeping in.
Laminating: Apply a coat of resin as the first coat. Lay on a glass-
fibre mat and impregnate with resin. Repeat this procedure until
you have built up a sufficient number of layers.
A polyester thrust tunnel should be finished as follows:
• Roughen the hardened resin/glass-fibre. Apply a top coat of resin.
• Treat the side of the tunnel which
comes into contact with water with
'epoxy paint' or 2-component polyu-
rethane paint.
• Then apply anti-fouling treatment if
required.
Installation manual BOW PRO Series Thrusters: BOWA0361, BOWA0364 and BOWA0421
D
136
23 / ")
64
3.6 Drilling the holes in the thrust-tunnel
- Mark the installation position of the
bow thruster by means of the interme-
diate flange.
- Use the drill pattern supplied, to deter-
mine the correct position of the holes to
be drilled.
Important: The pattern of the holes must
be positioned precisely on the centreline of
the tunnel.
Consult the template for the dimensions of the holes to be drilled.
Drill the holes through the thrust tunnel and take care that the holes
are free of burrs.
22 ( 7 / ") 22 ( 7 / ")
8 8
ø 30 (1 3 / ")
16
ø 9 ( 3 / ")
8
ø 9 ( 3 / ")
8
ø 9
( 3 / ")
8
37 (1 29 / ") 79 (3 1 / ")
64 8
3.7 Protection of the bow thruster against corrosion
To prevent corrosion problems,
do not use copper based anti-
fouling. Cathodic protection
is a 'must' for the protection of
all metal parts under water and
the bow thruster is supplied
with a zinc anode for this pur-
pose.
Corrosion of a steel or aluminium
thrust tunnel can be reduced by en-
suring that the tail piece is completely
insulated from the thrust-tunnel.
NOTE: The gaskets supplied are al-
ready electrically insulated. However
the bolts and the shaft need to be fit-
ted with insulation material, for exam-
ple nylon bushes.
ENGLISH
Insulation
bush
Gasket
Insulation
bush
19
020803.06