Interphase Twinscope Operation Manual page 18

MOLDED FAIRING BLOCK
If your installation requires a fairing block, you
may either have one made locally, or purchase
a molded plactic unit from Interphase or your
Interphase distributor.
For this transducer, the molded Fairing Block
Part Number is:
42-2005-000
Mount Transducer so it is Vertical
Waterline
Hull
Transducer
Waterline
Hull
Installing the Thru-hull Transducer
1) Drill a 1/8" pilot hole from inside the hull to assure
access to tighten the housing nut and clearance for the
transducer cables. If there is any hull irregularity near the
selected mounting location, it may be desirable to drill from
the outside.
2) Use a 1 - 1/16" hole saw and drill the hole from the
outside of the hull. Sand or clean the area around the hole,
inside and outside to insure that the sealing compound will
adhere properly to the hull. Select a marine grade bedding/
caulking compound and use according to the instructions.
3) Remove the bronze hex nut from the housing and cables.
4) Uncoil the two transducer cables and thread it through
the hole into the inside of the hull.
DANGER: DO NOT apply tension to the transducer
cables as this may sever internal connections. Apply a 1/8"
thick layer of sealant on the upper flat surface of the bronze
Keep parallel
housing and fairing block (if used).
to waterline !
5) From the outside of the hull, push the cables and
housing into the 1 - 1/16" hole. Twist the housing slightly
to squeeze out excess sealant. Carefully confirm that the
transducer is aligned so that the blunt rounded end (the
front) is pointed directly toward the front of the boat.
Forward
6) Install and tighten bronze hex nut (allow for swelling in
wooden hulls). Do not overtighten nut - especially if a
wooden fairing block is used as it will expand in water.
7) Remove excess sealant from the outside to assure
smooth water flow over the transducer.
DANGER: Wood hulls and fairing blocks will expand
after the boat is put back into the water, so it is important
Keep parallel
that the transducer be only hand-tightened until the wood
to waterline !
fully expands. Otherwise the wood fairing block may
crack.
DANGER: Be sure to check for leaks when the boat is
placed in the water. Allow at least 24 hours after
installation for any leak to appear.
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