Ensuring water safety and water safety is not just a recommendation, but a requirement for every boat owner. The most effective way to remove water trapped in the hull is to install an automatic water system. hold-pumpMany owners of PVC boats and metal boats underestimate the importance of this device, relying on manual scooping, but it is the automatic pump that can save the boat at a critical moment when the owner is not on board or is busy with management.
The installation process requires attention to detail, because the quality of the assembly depends on whether the system will work when it is most needed. Errors in sealing or choosing a wire section can lead to battery failure or flooding. In this article, we will discuss how to properly pump upIt works reliably and for many years.
Selection of equipment and preparation of materials
For small inflatable boats and canoes, compact models with a capacity of up to 500 liters per hour are often chosen, whereas for metal boats with a large bottom area, more powerful units of 750-1,100 l / h will be required. pressure, which must be sufficient to raise water to the height of the side, taking into account the hydraulic resistance of the hose.
In addition to the pump itself, you'll need a quality hose, a return valve, a fuse and reliable terminals. The hose should be flexible, but not collapse under vacuum when the pump is running. The return valve is a critical element that prevents water from flowing back into the hold after the pump is turned off. Without it, the water from the hose will drain back, causing the pump to turn on again and again, which will quickly land the battery.
⚠️ Attention: Do not use garden hoses for drinking water. Under the influence of temperature changes and sea salt, they quickly lose elasticity and can burst on a bend. Use a specialized hose for marine use.
For the electrical part of the preparation, stock up on a copper wire with a cross section of at least 2.5 mm2 (and for powerful pumps - 4 mm2 or more). Aluminum wires should not be used categorically because of their low conductivity and oxidation in humid conditions. switch-off or a switch for forced shutdown of the system, which must be installed in an easily accessible place at the control panel.
Definition of installation site and preparation of the bottom
Selecting a mounting point is the first step to determine the efficiency of the entire system. The pump should be installed at the lowest point of the hold where water flows. In flat-bottomed boats, it is usually the center of the transom or a specially designated pit. If the bottom has a complex geometry with rigidity ribs, installation may be required. drainage Or using a flexible hose to collect water from different angles.
When marking the hose outlet or pump housing installation (if it is submersible), the transom angle must be taken into account. The hole must be strictly perpendicular to the surface of the side at the exit point to ensure maximum leakage of the flange. For metal boats, the installation site should be treated with an anti-corrosion composition immediately after drilling to prevent the spread of rust from the edge of the hole.
It's important to have free access to the pump to service it, because the pump doesn't have to be clamped by the interior elements or the fuel tanks, and often it's mounted on a removable base or a false bottom that can be raised, and it allows you to quickly remove the impeller from the debris, sand or algae that inevitably enter the hold.
Use a transparent section of the hose or insert a transparent insert into the system immediately after the pump, which will allow you to visually monitor the pump operation and the presence of air in the system without disassembling the structure.
Mechanical installation: drilling and sealing
The most important step is to physically connect the pump in the boat to the off-shore water, to do this, a hole in the board or transom will be drilled with a diameter corresponding to the pump outlet or the passage section of the hose. It is extremely important to use a quality drill on metal or wood (depending on the material of the boat) and avoid the formation of ripped edges that can damage the seals.
The sealing of the connection is carried out using a marine sealant (polyurethane or silicone) and special access bushings. Apply the sealant not only on the thread, but also on the adjacent surfaces of the flange. For metal boats, brass or stainless passage elements are ideally suited, which are screwed on both sides of the side, clamping the material of the hull like a sandwich.
If you use a flexible hose running through the side, be sure to install a protective sleeve so that the sharp edge of the hole does not rub the hose with time from vibration. The hose should have a smooth curve without clamps. Sharp inflections reduce throughput and put extra stress on the pump engine, which can lead to its overheating.
| Parameter | Recommendation | Critical error |
|---|---|---|
| Hose material | UV-resistant PVC reinforced | Garden hose, rubber without reinforcement |
| Hose diameter | Strictly on the pump passport (usually 19-25 mm) | Use a narrower hose to fit |
| Hermetic | Polyurethane (Sikaflex, 3M 5200) | Acid silicone, building foam |
| Firming | Stainless clamps with screw | Plastic screeds, tape. |
⚠️ Attention: Before the clamps are finally tightened and the sealant is dry, run a water test strait. Get water into the hold and check the connections for leaks. It will be impossible to eliminate leaks after the boat is launched.
Electrical connection circuit of the pump
The electrical circuitry for connecting the pump must be reliable and moisture-proof. The standard circuit includes a battery, fuse, switch (tumbler) and pump itself. The fuse is installed as close as possible to the battery plus terminal (at a distance of no more than 15-20 cm), This protects the wiring from ignition in the event of a short circuit.
To connect the wires, use only tinted copper terminals, squeezed with a special tool, the crimper. Scrolls and soldering without subsequent insulation in conditions of vibration and humidity do not live long. Each connection must be carefully isolated with a shrink tube with a glue layer. Conventional insulation will quickly unstick from moisture.
Connection diagram:
[+] AKB --> [Fuse] --> [Tumbler] --> [Pompa] --> [-] AKB
If the pump is automatic, it has a built-in float switch or level sensor, in which case the constant battery plus (through the fuse) goes directly to the pump, and the circuit breaks out inside the device itself, but the manual switch on the panel is still necessary to force the system to turn on or completely de-energize the system during prolonged parking.
☑️ Electrical checks
Installation of the return valve and protection of the system
The return valve is mounted on the hose immediately after the pump, before the water is lifted on board, and its job is to keep the water in the hose when the pump is off, and this prevents the siphon effect, where the water flows back into the hold, and eliminates the need for the pump to refill the hose when it is turned on, and the valve is mandatory if the hose output hole is below the water level when the boat is fully loaded.
When mounting the valve, strictly monitor the flow direction indicated by the arrow on the device body. Incorrect orientation will block the water out completely. Some pump models already have built-in valves, but they are often less reliable than individual brass or plastic counterparts, so installing an additional external valve will not be superfluous.
To protect against large debris (leaves, branches, rags) on the inlet of the pump, it is recommended to install a filter mesh. However, be careful: the mesh requires regular cleaning. If it gets clogged, the pump will work idle. In conditions of severe contamination of the hold, it is better to use a pump with a whirlpool impeller, which is less sensitive to solid inclusions than centrifugal.
What to do if the pump buzzes but does not pump?
It's likely that the system has a traffic jam or a back valve has clogged, so try to force the water into the hose from the exit side or clean the valve, and check if the hose is clamped.
Testing and maintenance of the system
Once you've been able to plug in the pump in the boat, you need to do a comprehensive test. Don't just dry it. Fill the hold with water (you can use a bucket) and watch the pumping process. Take a look at the time it takes the pump to handle the volume and see if the bottom is completely drained. Ideally, the pump should turn off automatically when the water level drops below the sensor.
Regular maintenance will extend the life of the device. After each trip in salt water, it is recommended to wash the system with fresh water to prevent the crystallization of salt on the blades and in the mechanism. Once a season, remove the pump, clean the case of oily film and check the condition of the wires for oxidation.
Winter storage requires a special approach: the pump must be completely dismantled, dried and stored in a warm room; the residue of water inside the enclosure can freeze and rupture plastic or deform seals; the battery should also be turned off and stored for preservation.
The main secret of the durability of the pump is to prevent its operation "dry" for a long time and always use a fuse of the correct denomination.
Which battery is best used for pumping?
The best way to power a bilge pump is to use traction batteries (GEL or AGM) that are resistant to deep discharge, but if the pump is used infrequently and briefly, a conventional starter battery will do, provided it is fully charged, and the main thing is that the capacity must be sufficient to allow the pump to run for several hours at a time.
Can I connect the pump directly to the battery without a tumbler?
Technically, the automatic pump can be connected directly through the fuse, and it will turn on itself by the level sensor. However, the presence of a manual circuit breaker is necessary for safety: it allows you to force the pump to turn off in the event of a false alarm or when transporting a boat on a trailer to avoid battery discharge.
Why does the pump work but the water doesn't pump?
The most common causes: air plug in the hose (you need to pour water manually), clogging of the impeller with garbage, failure of the return valve (stick in the closed position) or too large a vertical pressure exceeding the capabilities of a particular pump model.
Should I lubricate the pump?
Most modern bilge pumps have sealed bearings and do not require lubrication. Trying to oil them can cause rubber seals to swell and fail, and only the movable mechanical parts of the float switch need to be lubricated if it starts to catch up using silicone lubrication.
How to choose the power pump for a boat with a length of 4-5 meters?
For a boat with a length of 4-5 meters (PVC or aluminum), the optimal performance will be 500-750 liters per hour. This is enough to quickly remove water from the wave or a little rain. Putting too powerful pump (1500+ l / h) does not make sense - it will consume a lot of energy and may not have time to suck up water due to the limited diameter of the regular holes in the hold.