Installation of sonar aluminum-boat It's not just a wired device to a transom, it's a complex engineering challenge that requires understanding the physics of ultrasound propagation in metal. Unlike fiberglass or PVC, aluminum has high electrical conductivity and stiffness, which creates specific interference and risks when you install it. Any mistake in sealing or choosing a mounting location can cause "noise" on the screen or, in the worst case, corrosion of the boat's hull.
The main challenge is that standard transom mounts designed for plastic may not be suitable or require improvement. Aluminum board has the ability to vibrate at high speeds, as well as quickly cool and heat up, which affects the density of the emitter. Kazanka, salute modern Alumacraft.
Competent installation will provide a clear picture of the bottom and fish even at plane speeds, which is why the choice of installation point on the aluminum housing often shifts from the geometric center of the transom to areas with less flux.
Choosing the installation method: drill or not?
The first and most important question that an aluminum boat owner faces is: disrupt the integrity of the hull or look for workarounds? Aluminum drilling is a technically simple process, but psychologically difficult for many anglers. If you decide to use an through mount, you will get the most stable signal and no vibrations, but you will lose the warranty on the hull if it is still valid.
The alternative is to use graffiti For aluminum boats with a flat or almost flat transom, this is often the best option. However, if the transom has a complex shape, reinforcements or pads, the clamping paws may not provide the necessary stiffness, in which case the sensor will "jump" on the screen when moving along the wave.
⚠️ Attention: When drilling aluminum side is strictly forbidden to use conventional steel drills without cooling - they instantly "lick" the metal and can break inside the hole. Use only special aluminum drills with a trihedral point and abundantly lubricate the drilling site.
There is also a compromise option - installing a sensor inside the housing (in-hull), but for aluminum it is only applicable in exceptional cases. Since the metal shields the signal, the sensor will have to be glued into a cut piece of the bottom or use special epoxy compounds, agreed on the density of aluminum, which requires a high skill of the master.
Preparation of tools and materials
The quality of the installation depends on what you do. Lowrance, Garmin or Humminbird You're going to need a set of specialized tools, and you don't have to rely on household tools, because working with marine materials requires precision and purity.
First of all, take care of sealants. Conventional silicone from a construction store will not work — it will peel off under the influence of vibration and fuel. You need a polyurethane or specialized marine sealant, for example, based on the basis of MS polymersYou'll also need degreasing agents that don't leave the film behind, and abrasive materials to prepare the surface.
Before applying the sealant, warm the aluminum surface and the tube with the sealant to room temperature (about 20 ° C. Cold metal worsens adhesion, and the composition may not be grasped correctly.
List of required equipment:
- 🛠️ A drill or screwdriver with a speed regulator (low revs are important for aluminum).
- 🔩 A set of drills for metal (cobalt or with hard alloy soldering).
- 🧴 Degreasing agent (acetone or specialized cleaner).
- 🔌 Sealant for marine applications (polyurethane).
- 📏 Marking tool (kern, marker, roulette).
Pay special attention to cable channels and corrugated. The wiring on an aluminum boat should not lie open on the metal to avoid rubbing the insulation and short circuit on the hull. Use high-quality corrugated and plastic clips for fixation.
Finding the Best Place to Install
Setting the mounting point is 80 percent of the success of the whole operation. On an aluminum boat, the clean water zone can be very narrow. You need to find a place where the flow of water as the boat moves will flow around the sensor evenly, without vortices and bubbles.
Often aluminum cases have longitudinal or transom stiffness ribs, you can't attach the sensor directly to the edge, it won't work properly, you have to find a flat area between the ribs, and if there's no flat area, sometimes you have to make a special adapter pad out of textolite or the same aluminum that's glued onto the side.
How do you find a no-twist zone?
Pour water over the tan of a launched boat (at low speed) or use a soap foam. See where the water flows smoothly, without bubbling. That's where you need to attach the sensor, often closer to the cheekbone or, conversely, strictly in the center, depending on the shape of the bottom.
When choosing a location, also consider the angle of inclination. The sensor should look strictly down, perpendicular to the surface of the water when the boat is in the operating position (on planing). If the sensor is upside down or down, you lose the signal at speed.
Important criteria for choosing a place:
- 🌊 Absence of air bubbles in the water stream.
- 📏 Sufficient distance from the engine (minimum 30-40 cm) to avoid hydrodynamic noise from the propeller.
- 🔌 The possibility of convenient cable laying to the head unit without unnecessary hinges.
Technology of end-to-end installation (through the board)
If you've chosen the through mounting method, opening the hole is key, first the mounting site is thoroughly cleaned and degreased, then the center of the future hole is curled so that the drill doesn't "walk" through the slippery aluminum.
Drilling should be done carefully, without heavy pressure, periodically removing the shavings. The diameter of the hole should correspond exactly to the diameter of the thread of the sensor or bushing. After drilling, the edges of the holes are necessarily treated with an anti-corrosion composition, since aluminum is actively oxidized on a fresh cut.
| Parameter | Recommendation | Critical error |
|---|---|---|
| Diameter of the drill | Strictly specificated sensor | The "eye drilling" will lead to leaks |
| Hermetization | Polyurethane sealant + washers | Use of silicone or tape |
| Puff. | Dynamometer key (if indicated) | The retraction will lead to deformation of the sensor body |
| Cable | With a supply of length and loops for water runoff | A strained cable transmitting vibration to the sensor |
When the sensor is installed across the side, a special sleeve is used, a sealant is applied to the thread, the sensor is inserted into the hole, and the inside of the side is fixed by a nut. Between the boat hull and the nut, and between the sensor and the board, rubber or plastic washers from the kit must be installed, they compensate for vibration and prevent electrochemical corrosion between the heterogeneous metals (aluminum and brass / bronze of the sensor).
☑️ Checklist of end-to-end installation
Installation on a transom plate without drilling
For those who don't want to drill the hull, there are transom mounts. On flat-transe aluminum boats, they work quite well, but they need to be installed correctly, and the main goal is to keep the legs tightly pressed against the metal.
Often, standard plastic feet slide over smooth aluminum, and to avoid this, you can stick a thin layer of anti-slip rubber onto the inner surface of the legs, or use 3M VHB double-sided tape in combination with the main fastener, which will increase friction and reduce vibration.
⚠️ Attention: When using aluminium boat clamping mounts, watch for the galvanic pair. If the mounting screws are steel and the boat is aluminum, rapid corrosion will begin at the contact point when water enters. Use only stainless steel (A2, A4) or brass, and be sure to isolate the contact of metals with lubrication.
The angle of the sensor on the transom bracket is controlled by moving the bar up and down the slots. After the initial setup, be sure to run a test run. If the picture breaks at speed, perhaps the sensor gets out of the water (cavitation) or, conversely, is too deep and creates resistance.
The main advantage of transom mounting is mobility, and you can easily remove the sonar for storage or transportation, which reduces the risk of equipment theft and damage to the sensor on the berth.
Sealing and protection of compounds
Aluminum is a metal that is easily electrochemically corroded, especially when in contact with copper cable veins or water. So sealing all connections is a critical step. Water should have no access to the thread or the cable's entry point into the sensor.
To protect the contacts inside the boat, use adhesive shrink tubes. When heated, the glue melts and fills all the voids, creating a monolithic protection. The usual insulation on the boat does not live long - it dries and unsticks from vibration.
The cable that passes through the side should be protected from rubbing. If the cable passes through a hole in the metal, use a rubber oment or bushing. The sharp edge of an aluminum sheet can cut the insulation in one season of active use.
- 🔌 Use it. shrinkage with glue for all twists and joints.
- 🛡️ Lay the cable in the corrugated or cable channel, fixing it every 30-40 cm.
- 💧 Treat the exit of the cable from the sensor with a special spray-insulator.
Customization and calibration after installation
After you physically install and dry the sealant (usually 24 hours), you get the adjustment step, start the engine and go out into clean water, first check the sound sonar at idle, the picture should be stable, without vertical interference lanes.
Then accelerate the boat to operational speeds. If the signal is lost, try lowering the sensor a little bit. If there is noise, perhaps the sensor is too deep and creates a cavitation bubble.Sensitivity) and noise level (Noise Filter) in the instrument menu.
Aluminum boats have high levels of background noise from the engine and hull vibration, and sound sounder settings should include noise suppression or high frequency sensitivity, which will help cut off excess illumination and get a clear picture of the bottom.
Why does the sonar show "porridge" on an aluminum boat?
A common cause is poor contact of the battery mass (minus) with the boat hull or engine, or electromagnetic tips from poor-quality wiring. Check the reliability of the terminal mounting and use a shielded cable for the sensor.
Can I attach the sensor to the glue without drilling?
There are sensors for in-hull, but they're for fiberglass. You can't glue aluminum to a conventional sensor, because the metal shields the signal. There are special adapters that stick into the cutout in the bottom, but it's a complicated procedure that requires welding or working with epoxy resins.
How often should I check the leakage?
It is recommended to conduct a visual inspection of the anchorage and sealing sites at the beginning and end of each season. If the boat is kept on the water constantly, the check should be done once a month.