Airmar DST800 Retractable without Valve—TRIDUCER® Multisensor - Manual (Page 4)

4 Copyright © 2003 - 2010 Airmar Technology Corp. All rights reserved.
3. From inside the hull, use a 60mm or 2-3/8" hole saw to cut through the
inner skin and most of the core. The core material can be very soft.
Apply only light pressure to the hole saw after cutting through the inner
skin to avoid accidentally cutting the outer skin.
4. Remove the plug of core material so the inside of the outer skin and the
inner core of the hull are fully exposed. Sand and clean the inner skin,
core, and the outer skin around the hole.
5. If you are skilled with fiberglass, saturate a layer of fiberglass cloth with
a suitable resin and lay it inside the hole to seal and strengthen the
core. Add layers until the hole is the correct diameter.
Alternatively, a hollow or solid cylinder of the correct diameter can be
coated with wax and taped in place. Fill the gap between the cylinder and
hull with casting epoxy. After the epoxy has set, remove the cylinder.
6. Sand and clean the area around the hole, inside and outside, to ensure
that the marine sealant will adhere properly to the hull. If there is any
petroleum residue inside the hull, remove it with either mild household
detergent or a weak solvent (alcohol) before sanding.
7. Proceed with “Bedding” and “Installing” on page 3.
Maintenance, Parts & Replacement
Using the Blanking Plug
To protect the paddlewheel, use the blanking plug:
• When the boat will be kept in salt water for more than a week.
• When the boat will be removed from the water.
• When aquatic growth buildup on the paddlewheel is suspected due to
inaccurate readings from the instrument.
1. The O-rings must be intact and well lubricated to make a watertight seal.
On the blanking plug, inspect the O-rings (replace if necessary) and
lubricate them with the silicone lubricant supplied or petroleum jelly
(Vaseline
® ) (see Figure 5).
2. Remove the insert from the housing by removing the safety wire and
unscrewing the cap nut (see Figure 3). This will jack out the insert.
3. With the blanking plug ready in one hand, pull the insert most of the way
out. Remove the insert and rapidly replace it with the blanking plug.
With practice, only 250ml (10oz.) of water will enter the boat. Be sure
the blanking plug is fully inserted into the housing.
4. Screw the cap nut several turns until the threads are engaged.
Continue to tighten the cap nut completely for a watertight seal.
Hand tighten only. Do not over tighten.
5. Reattach the safety wire to prevent the blanking plug from backing out
in the unlikely event that the cap nut fails or is screwed on incorrectly.
Servicing the Insert
Aquatic growth can accumulate rapidly on the depth transducer’s surface
and impede or freeze the paddlewheel’s rotation reducing performance
within weeks. Clean the insert with a Scotch-Brite® scour pad and mild
household detergent, being careful to avoid scratching the depth
transducer. If fouling is severe, remove the paddlewheel (see step #1
below). Lightly wet sand it with fine grade wet/dry paper.
The water lubricated paddlewheel bearings have a life of up to 5 years on
low-speed boats [less than 10kn (11MPH)] and 1 year on high-speed
vessels. Paddlewheels can fracture and shafts can bend due to impact
with water borne objects and mishandling in boat yards. O-rings must be
free of abrasions and cuts to ensure a watertight seal. Order a
replacement Paddlewheel Kit 33-398-04.
1. To remove the old paddlewheel shaft, grasp the end with small diagonal
wire cutters and pull (see Figure 5).
2. Place the new paddlewheel in the cavity with the flat side of the blade
facing the same direction as the arrow on the top of the insert.
3. Tap the new shaft into place until the end is flush with the outside wall
of the insert.
4. Install a large O-ring near the top of the insert. Install a small
O-ring near the paddlewheel.
5. Place the remaining two O-rings on the blanking plug near the bottom.
Winterizing
After the boat has been hauled for winter storage, remove the blanking
plug to let the water drain away before reinserting it. This will prevent any
water from freezing around the blanking plug and possibly cracking it.
Replacement Multisensor & Parts
The information needed to order a replacement Airmar multisensor is
printed on the cable tag. Do not remove this tag. When ordering,
specify the part number, date, and frequency in kHz. For convenient
reference, record this information on the top of page one.
Lost, broken, or worn parts should be replaced immediately. If you
have purchased a plastic housing and have a wood hull or desire
greater strength, purchase an Airmar metal housing.
Obtain parts from your instrument manufacturer or marine dealer.
Gemeco Tel: 803.693.0777
(USA) Fax: 803.693.0477
email: [email protected]
Airmar EMEA Tel: +33.(0)2.23.52.06.48
(Europe, Middle East, Africa) Fax: +33.(0)2.23.52.06.49
email: [email protected]
Blanking
Plug
Hull Nut or
Isolation Bushing
Paddlewheel,
Shaft & O-rings Housing, Nut & Washer
33-538-01
04-004 (plastic)
02-030 (bronze)
02-570-01 (stainless steel)
04-186-1 (isolation
bushing)
33-398-04
33-417 (plastic, P17)
33-100 (bronze, B17)
33-495-01 (stainless
steel SS577)
Figure 5. Replacing the paddlewheel and O-rings
arrow
flat side of
blade faces bow
shaft
blanking
insert
large
O-ring
small
O-ring(s)
Copyright © 2006 Airmar Technology Corp.
BOW
►
AIRMAR
®
TECHNOLOGY CORPORATION
35 Meadowbrook Drive, Milford, New Hampshire 03055-4613, USA
www.airmar.com
Figure 4. Preparing a cored fiberglass hull
inner skin
core
outer skin
solid or hollow cylinder
pour in
casting
epoxy
9-12 mm
(3/8-1/2")
larger than the
hole through the
hull’s outer skin
hull thickness
Copyright © 2005 Airmar Technology Corp.
plug