Airmar DST800 Retractable with Valve—TRIDUCER® Multisensor - Manual (Page 4)

4
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” (see page 3).
Operation & Maintenance
How the Valve Works
THE VALVE IS NOT A WATERTIGHT SEAL! The multisensor
incorporates a self-closing valve which minimizes the flow of water into the
boat when the insert is removed. The curved flap valve is activated by both
a spring and water pressure. Water pushes the flap valve upward to block
the opening, so there is no gush of water into the boat. Always install the
insert or the blanking plug secured with the cap nut and safety wire for a
watertight seal.
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 up the insert.
Remove the insert with a slow pulling motion. Replace it by sliding the
blanking plug into the housing.
NOTE: In the very unlikely event that the valve breaks, replace the
housing the next time the boat is hauled.
3. With the blanking plug fully inserted, screw the cap nut several turns until
the threads are engaged. Continue to tighten the cap nut completely.
Hand tighten only. Do not over tighten.
NOTE: The blanking plug must be fully inserted in the housing and the
cap nut screwed on completely for a watertight seal.
4. 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.
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.
Servicing the Insert
Aquatic growth can accumulate rapidly on the depth transducer’s face 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 No. 33-540-01.
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 the yellow O-ring near the top of the insert. Install a small O-ring
near the paddlewheel.
5. Place the remaining two small O-rings near the bottom of the blanking
plug.
Replacement Sensor & 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, Hull Nut & Washer
33-538-01
04-004 (plastic)
02-530-02 (stainless)
04-186-1 (isolation)
33-398-04
Valve:
33-510-01 (plastic, P617V)
33-588-01 (bronze, B617V)
33-617-01 (stainless, SS617V)
NO Valve:
33-100 bronze low-profile, B17
33-224-01 bronze flush, B21
33-094-01 stainless low profile, SS577
Copyright © 2005 - 2014 Airmar Technology Corp. All rights reserved.
Figure 5. Replacing the paddlewheel and O-rings
arrow
flat side
of blade
shaft
blanking
insert
faces bow
yellow
O-ring
small
O-ring(s)
Copyright © 2005 Airmar Technology Corp
BOW ►
plug
35 Meadowbrook Drive, Milford, New Hampshire 03055-4613, USA
• www.airmar.com