AIRMAR B17 Thru Hull Transducer Instruction Manual
- June 13, 2024
- AIRMAR
Table of Contents
AIRMAR B17 Thru Hull Transducer Instruction Manual
Follow the precautions below for optimal product performance and to reduce the risk of property damage, personal injury, and/or death.
WARNING: Always wear safety glasses, a dust mask, and ear protection when installing.
WARNING: Immediately check for leaks when the boat is placed in the water. Do not leave the boat unchecked for more than three hours. Even a small leak may allow considerable water to accumulate.
WARNING: Retractable models—All the O-rings must be intact and well lubricated to make a watertight seal. Do not dry fit the insert in the housing. Attempting to install the insert without lubricating all the O-rings may damage them, possibly preventing full insertion and a watertight seal.
WARNING: Retractable models—Always attach the safety wire to prevent the insert or blanking plug from backing out in the unlikely event that the cap nut fails or is screwed on incorrectly.
WARNING: B117 and P319—Do not use the spacer if there is insufficient space to tighten the nut, or it is within 11mm (1/2″) of the top of the housing.
CAUTION: Never pull, carry, or hold the transducer by its cable. This may sever internal connections.
CAUTION: Plastic housing—Never use a fairing with a plastic housing; the protruding sensor would be vulnerable to damage from impact.
CAUTION: Metal housing—Never install a metal housing in a vessel with a positive ground system.
CAUTION: Never use solvents. Cleaner, fuel, sealant, paint, and other products may contain solvents that can damage plastic parts, especially the transducer’s face.
CAUTION: Never power sand or pressure wash the sensor. It may weaken the structure or damage the internal components.
IMPORTANT: Read the instructions completely before proceeding with the installation. These instructions supersede any other instructions in your instrument manual if they differ.
Record the information found on the cable tag for future reference.
Part No. ___ Date _ Frequency ____
kHz
Applications
-
Best performance on hull deadrise angle through 7°.
Can accommodate up to a 12° deadrise angle. -
Plastic housing recommended for fiberglass or metal hull only.
Never install a plastic housing in a wood hull since swelling of the wood may fracture the plastic. -
Bronze housing recommended for fiberglass or wood hull. Never install a bronze housing in a metal hull because electrolytic corrosion will occur.
Tools & Materials
- Safety glasses
- Dust mask
- Ear protection
- Electric drill [Ø 10mm (3/8″) or larger chuck capacity}
- Drill bit: Ø 3mm or 1/8″
- Hole saw (see table below)
- Countersink tool (installing a flush housing)
- Sandpaper
- Mild household detergent or weak solvent (such as alcohol)
- File (installation in a metal hull)
- Marine sealant (suitable for below waterline)
- Additional washer [for aluminum hull less than 6mm (1/4″) thick]
- Slip-joint pliers (installing a metal housing)
- Grommet(s) (some installations)
- Cable ties
- Water-based anti-fouling coating (mandatory in saltwater) Installation in a cored fiberglass hull (page 4):
- Hole saw for hull interior: (see table below)
- Fiberglass cloth and resin or Cylinder, wax, tape, and casting epoxy
Identify Your Model
The model name is printed on the cable tag.
Model (Housing)| Minimum vertical space inside the hull| Outside
Hull Ø Hole Saw| Cored Fiberglass Hull Hull Interior Ø Hole Saw
---|---|---|---
Low-profile: B117 P19 P319| 95mm (3-3/4″)| Ø 51mm or 2″| Ø 60mm or 2-3/8″
Retractable Low-profile: B17 P17| 200mm (8″)| Ø 51mm or 2″| Ø 60mm or 2-3/8″
Retractable Flush: P217 P314| 200mm (8″)| Ø 51mm or 2″| Ø 60mm or 2-3/8″
-
large displacement hulls
-
small displacement hulls
-
planing hulls
-
outboard and I/O
-
stepped hull
-
fin keel sailboats
-
full keel sailboats
Figure 1.
Best location for transducer
Mounting Location
Guidelines
CAUTION: Do not mount the transducer in line with or near water intake or discharge openings or behind strakes, fittings, or hull irregularities that will disturb the water flow.
- The water flowing under the hull must be smooth with a minimum of bubbles and turbulence, especially at high speeds.
- The transducer must be continuously immersed in water at all speeds.
- The transducer beam must be unobstructed by the keel or propeller shaft(s).
- Choose a location away from interference caused by power and radiation sources such as: the propeller(s) and shaft(s), other machinery, other echosounders, and other cables. The lower the noise level, the higher the echosounder gain setting that can be used.
- Choose a location with a minimal deadrise angle, so the transducer beam will be aimed at the bottom.
- Choose an accessible spot inside the vessel with adequate vertical space for the height of the housing, tightening the nuts, and removing any insert (see the table on page 1).
Boat Types (Figure 1)
-
Displacement hull powerboats —Locate amidships near the centerline. The side of the hull where the propeller blades are moving downward is preferred.
-
Planing hull powerboats —Mount well aft, on or near the centerline, and well inboard of the first set of lifting strakes to ensure that the transducer will be in contact with the water at high speeds. The side of the hull where the propeller blades are moving downward is preferred.
Outboard and I/O —Mount just forward of the engine(s).
Inboard—Mount well ahead of the propeller(s) and shaft(s).
Stepped hull —Mount just ahead of the first step. Boat capable of speeds above 25kn (29MPH)—Review the installation location and operating results of similar boats before proceeding. -
Fin keel sailboats —Mount on or near the centerline and forward of the fin keel 300 to 600mm (1 2′).
-
Full keel sailboats —Locate amidships and away from the keel at the point of minimum deadrise angle.
Installation
Hole Drilling
Cored fiberglass hull —Follow separate instructions on page 3.
-
Drill a Ø 3 mm or 1/8″ pilot hole from inside the hull. If there is a rib, strut, or other hull irregularity near the selected mounting location, drill from the outside.
-
Using the appropriate size outside hull hole saw, cut a hole perpendicular to the hull from outside the boat (see table on page 1).
Flush housing —Use a countersink tool to make a ‘seat’ in the hull. -
Sand and clean the area around the hole, inside and outside, to ensure that the 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.
Metal hull —Remove all burrs with a file and sandpaper.
Bedding
CAUTION: Be sure the surfaces to be bedded are clean and dry.
Apply a 2mm (1/16″) thick layer of marine sealant around the flange and up the sidewall of the housing (Figure 2). The sealant must extend 6mm (1/4″) higher than the combined thickness of the hull, washer, any spacer, and the hull nut. This will ensure there is marine sealant in the threads to seal the hull and to hold the hull nut securely in place.
Installing
NOTE: Ignore any arrows on the housing, insert, and blanking plug.
-
From outside the hull, push the housing (and cable if applicable) into the mounting hole using a twisting motion to squeeze out excess marine sealant (Figure 2).
Figure 2. Bedding and installing
Copyright © 2006 – 2010 Airmar Technology Corp.
-
From inside the hull, slide the washer onto the housing.
B117 and P319 —Also slide the spacer onto the housing and rest it against the washer. Do not use the spacer if there is insufficient space to tighten the nut or it is within 11mm (1/2″) of the top of the housing. Aluminum hull less than 6mm (1/4″) thick—If necessary, use an additional rubbery, fiberglass, or plastic washer. Never use bronze because electrolytic corrosion will occur. Never use wood because it will swell, possibly fracturing the plastic housing. -
Screw the hull nut in place.
Plastic housing —If your housing has wrenching flats, do not clamp tightly possibly causing the housing to fracture.
Plastic hull nut —Hand tighten only. Do not over tighten.
Metal hull nut —Tighten with slip-joint pliers.
Cored fiberglass hull —Do not over tighten, crushing the hull.
Woodhull —Allow the wood to swell before tightening the hull nut. -
Remove any excess marine sealant on the outside of the hull to ensure smooth water flow under the transducer.
Retractable Models Only
-
All the O-rings must be intact and well lubricated to make a watertight seal. After the marine sealant cures, inspect the O-rings on the transducer insert (replace if necessary) and lubricate them with the silicone lubricant supplied.
-
Slide the insert into the housing. Seat the insert into place with a twisting motion until the key fits into the notch. Be careful not to rotate the housing and disturb the marine sealant. Screw the cap nut in place. Hand tighten only. Do not over tighten.
D800, DT800 —Be sure the insert is fully inserted into the housing. 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.
fiberglass hull plastic or bronze housing (P319/B117 shown)
fiberglass or wood hull flush housing retractable insert (P217 shown)
fiberglass or wood hull metal housing retractable insert (B17 shown)
Figure 2. Bedding and installing -
Attach the safety wire to prevent the insert from backing out in the unlikely event that the cap nut fails or is screwed on incorrectly (Figure 2).
Plastic housing— Attach the safety wire to one eye in the hull nut. Keeping the wire taut throughout, lead the wire in a counterclockwise direction and thread it through one eye in the cap nut, the pull ring/eye in the insert, the second eye in the cap nut, and the second eye in the hull nut. Twist the wire securely to itself.
Metal housing— Wrap one end of the safety wire tightly around the housing and twist it together with the long end. Keeping the wire taut throughout, lead the wire straight up and through the eye in the cap nut. Loop the wire through the pull ring/eye in the insert and twist it securely to itself.
Cable Routing & Connecting
CAUTION: If your transducer came with a connector, do not remove it to ease cable routing. If the cable must be cut and spliced, use Airmar’s splash- proof Junction Box No. 33-035 and follow the instructions provided. Removing the waterproof connector or cutting the cable, except when using a watertight junction box, will void the sensor warranty.
- Route the cable to the instrument, being careful not to tear the cable jacket when passing it through the bulkhead(s) and other parts of the boat. Use grommets to prevent chafing. To reduce electrical interference, separate the transducer cable from other electrical wiring and the engine. Coil any excess cable and secure it in place using cable ties to prevent damage.
- Refer to the echosounder owner’s manual to connect the transducer to the instrument.
Checking for Leaks
When the boat is placed in the water, immediately check around the transducer for leaks. Note that very small leaks may not be readily observed. Do not leave the boat in the water for more than 3 hours before checking it again. If there is a small leak, there may be considerable bilge water accumulation after 24 hours. If a leak is observed, repeat “Bedding” and “Installing” immediately (page 2).
Installation in a Cored Fiberglass Hull
The core (wood or foam) must be cut and sealed carefully. The core must be protected from water seepage, and the hull must be reinforced to prevent it from crushing under the hull nut allowing the housing to become loose.
CAUTION: Completely seal the hull to prevent water seepage into the core.
-
Drill a Ø 3 mm or 1/8″ pilot hole from inside the hull. If there is a rib, strut, or other hull irregularity near the selected mounting location, drill from the outside (Figure 3). (If the hole is drilled in the wrong location, drill a second hole in a better location. Apply masking tape to the outside of the hull over the incorrect hole and fill it with epoxy.)
-
Using the appropriate size outside hull hole saw, cut a hole from outside the hull through the outer skin only (see table on page 1).
-
From inside the hull using the appropriate size hull interior hole saw, cut through the inner skin and most of the core (see table on page 1). 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.
-
Remove the plug of core material, so the inside of the outer skin and the inner core of the hull is fully exposed. Sand and clean the\ inner skin, core, and the outer skin around the hole
Figure 3. Preparing a cored fiberglass hull
Copyright © 1996 – 2021 Airmar Technology Corp.
-
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.
- 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.
- Proceed with “Bedding” and “Installing” (page 2).
Anti-fouling Coating
Surfaces exposed to saltwater must be covered with an antifouling coating. Use
water-based anti fouling coating made for transducers only. Never use ketone-
based paint since ketones can attack many plastics possibly damaging the
transducer. Brush on anti-fouling coating every 6 months or at the beginning
of each boating season.
Retractable Models: Coat the following surfaces
- Outside wall of the insert below lower O-ring and exposed end
- Bore of the housing up 30mm (1-1/4”)
- Exterior flange of the housing
- Blanking plug below the lower O-ring including the exposed end
Maintenance, Parts & Replacement
Cleaning
Aquatic growth can accumulate rapidly on the transducer’s face, reducing its
performance within weeks. Clean the surface with a Scotch-Brite® scour pad and
mild household detergent, being careful to avoid making scratches. If the
fouling is severe, lightly wet sand the surface with fine grade wet/dry paper.
Retractable Models
Using the Blanking Plug
To protect the insert, use the blanking plug:
- When the boat will be kept in saltwater for more than a week.
- When the boat will be removed from the water.
- When aquatic growth buildup on the insert is suspected due to inaccurate readings from the instrument.
- All 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 (Figure 4).
- Remove the transducer insert from the housing by removing the safety wire and unscrewing the cap nut (Figure 2).
- With the blanking plug ready in one hand, pull the transducer insert most of the way out. Remove the insert and rapidly replace it with the blanking plug. Seat it into place with a pushing twisting motion until the key fits into the notch in the housing. With practice, only 250ml (10oz.) of water will enter the boat. Screw the cap nut in place. Hand tighten only. Do not over tighten. D800, DT800—Be sure the blanking plug is fully inserted into the housing. 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.
- 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
Replacing the O-rings
All the O-rings must be intact and well lubricated to make a watertight seal.
Inspect the spare O-rings and lubricate them with silicone lubricant or
petroleum jelly. Replace the O-rings.
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, possibly cracking the plastic.
Replacement Transducer & Parts
The information needed to order a replacement transducer 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, and worn parts should be replaced immediately. Obtain parts from your instrument manufacturer or marine dealer.
Gemeco USA
Tel: 803-693-0777
Email: sales@gemeco.com
Airmar EMEA Europe, Middle East, Africa
Tel: +33.(0)2.23.52.06.48
Email: sales@airmar-emea.com
35 Meadowbrook Drive, Milford, New Hampshire 03055-4613, USA
www.airmar.com
4 Copyright © 2006 – 2021 Airmar Technology Corporation
