The polyvinyl chloride (PVC) inflatable boat is a versatile craft valued for its compactness and lightness. However, to turn an inflatable boat into a fully-fledged motorized vessel that can withstand the wave and propeller thrust, a well-designed engine mounting system is essential, and it is the quality of the motor-hull connection that determines not only the speed of movement, but also the safety of the crew on the water.
The main node that handles all the loads of the propeller is the transom. It's a rigid vertical plate that is built into or attached to the stern of the boat. The wrong choice of the type of transmutant or the violation of the technology of its installation can lead to the failure of the engine, which on the go can lead to the tipping of the boat or the loss of expensive equipment. In this article, we will discuss in detail all aspects of the selection, installation and operation of PVC outboard systems for boats.
Design features of feed transoms
The traverse is a rigid structure that transfers the thrust from the engine to the hull of the vessel, and depending on the design of the boat, these elements can be glued or removable. Pluted transmolant It is part of the power set of paiola and rigidly fixed inside the cylinders, which provides maximum rigidity, but increases the weight and dimensions of the boat in the assembled form.
Removable transverses, in turn, are divided into hinged and inserted. Hinged models are attached to cylinders with special pockets and slings covering the diameter of the cylinder, which allow you to adjust the height of the landing engine, but require careful pumping of cylinders to ensure rigidity. False transes They are fixed in special pockets on the bottom or sides and are often used on small boats where powerful engines are not required.
The most common material used for transoms is moisture-resistant plywood, coated with boat lacquer or enamel, or composite materials. The board is usually 12 to 25 mm thick, depending on the power of the intended motor, and it is important that the surface is smooth, chipped, so as not to damage the PVC fabric when frictioning.
Choosing a transom for engine power
The right transom is directly dependent on the power of the outboard motor you plan to use. PVC boat manufacturers always specify the maximum power allowed for each model, exceeding these limits leads to deformation of the aft part and potential rupture of the seams.
For motors up to 5 hp, a hinged trans-board that is attached by slings is often enough. However, for engines in 6-8 hp, it is recommended to use rigid structures with metal reinforcing elements. Motors over 10 hp require exceptionally rigid mounting, most often glued to the power set, since the vibrations and thrust of the screw create enormous pressure on the stern.
The choice also includes the type of propeller, and if you plan to use high-speed propellers with a large pitch, the load on the transom increases exponentially, and in such cases, even with a formal matching of power, it is better to choose a transom with a margin of safety.
When buying a boat with a hinged transom, check the quality of the slings: they must be made of durable tape, and the places of their sewing to the pockets are reinforced with additional layers of fabric.
Instructions for the installation of the hinged transcent
The installation of the hinged transom is a very careful process, because it's the engine's stability that depends on it, and you have to pump the boat's cylinders to the working pressure, and if you don't have enough pressure, you'll have to soften the sides, and the transom will walk under load, which can lead to it slipping out.
Then you put the pockets of the transom on the board, making sure that they sit tight and symmetrical, slings or belts should be tightened evenly from both sides, if you pull one side stronger than the other, the transom will get skewed, which will lead to yaw boats on the course and uneven wear of the anchorages.
⚠️ Warning: Never install the engine on an incompletely inflected boat. Soft sides will not be able to compensate for the hard drive, and the engine can tilt sharply to the side, creating an emergency situation.
The final step is to check the stability of the locking, and if you take a rumble or a deadwheel, you try to swing the transom from side to side, the backflip should be minimal, and if the transom walks freely, you either need to pump the cylinders or tighten the fasteners more tightly.
☑️ Verification of transone installation
Installation of the suspension device on the glued transom
Owners of transmesse-stick boats are spared the trouble of pumping the sides to fix the engine, but are faced with the task of properly positioning the engine. The suspension device must be mounted strictly in the center of the transmesse. Shifting the engine to the left or right will lead to permanent rolling of the boat, which worsens the performance and increases the risk of flooding the waves.
To fix the motor, special pinch screws or rods are used. When installing, you must ensure that there are no gaps between the sole of the deadwell and the plane of the transom. If the transom has a coating of non-slip tape (carpet), the screws must be tightened with enough force to compress the pile, but not damaging the fabric.
The important thing is the height of the installation. The lower anti-cavitation plate should be 10 to 20 mm below the bottom of the boat. If you lift the engine higher, you get cavitation and loss of traction; if you lower it, you increase water resistance and the risk of hitting underwater obstacles.
Why do you need an anti-cavitation plate?
An anti-cavitation plate is a horizontal protrusion above the propeller, and it prevents air from being sucked from the surface of the water to the propeller blades in sharp maneuvers or on the wave, preserving traction and protecting the engine from overheating.
Typical errors in the fastening of the motor
One of the most common mistakes is to use homemade transmuters made of inappropriate materials: conventional building plywood without special impregnation quickly gains water, becomes heavy and rots, losing its load-bearing capacity, which can lead to a sudden collapse of the transmuner at full speed.
Another mistake is ignoring the safety rope, and many aquatic motorists rely only on regular engine rods, but vibration has the ability to gradually weaken even tightly clamped screws, and lack of insurance is a direct route to losing the engine.
It is also common to get the wrong centering: if the motor is crooked, the boat will be constantly led aside ("scour"), and the operator will have to constantly adjust the course, leading to rapid fatigue and fuel overrun.
| Mistake. | Consequence | Decision |
|---|---|---|
| Weak belt fastener | Engine derailment in the water | Use belts with fastexes or carabiners |
| Soft sides | transom skewing, boat roll | Control pressure with a gauge |
| Lack of insurance | Loss of engine during vibration | You need to tie the motor with a cable |
| Wrong height. | Cavitation or nosebugging | Adjust the height of the suspension device |
The main enemy of reliable fastening is vibration. Regularly check the tightening of all screws and belts during the first hour of operation and after each long parking.
Protection against breakdown and engine insurance
Even with a perfectly assembled design, the risk of engine failure cannot be completely eliminated, especially when passing a steep wave or braking sharply. Therefore, the use of a safety rope is a mandatory safety rule. The cable must be made of a synthetic material (nylon, polypropylene), which does not rot and has high tensile strength.
One end of the cable is attached to the motor's deadwheel (usually a transport handle or a special dice hole), and the second to the rim on the bow of the boat or to the paddle handle, which runs through the nose handle. The cable must be stretched, but have a small margin of length, allowing the motor to walk a little while while the suspension is working, but not allowing it to go underwater when the suspension is broken.
For hinged transverses, there are additional fixation systems, such as carbines that connect transom slings to cylinder rings, which prevents the transom from slipping downwards in a sharp jerk, and the use of such elements greatly improves the reliability of the entire system.
Can I use the chain for insurance?
The metal chain is not recommended, it has a lot of weight, which puts additional strain on the stern, and when jerking, it can damage the boat hull or the engine's deadwheel due to lack of elasticity.
Maintenance and care of fasteners
Operating in an aqueous environment, especially salty ones, aggressively affects the metal parts of the attachment, and after each foray into the water, the transom and fasteners must be washed with fresh water, which will remove salt, sand and silt, which can act as an abrasive or a corrosion catalyst.
Check the condition of the wooden transoms regularly for delamination or cracking. Even a microscopic crack under load can grow quickly. If you find damage to the lacquer coating, immediately hide and paint over the damaged area to prevent moisture from entering the plywood.
The fabric elements of the hinged transverses also require maintenance. Mud and sand stuck in the sling fibers rub the threads. Periodic washing of removable elements with soft soap will prolong their life. Do not dry PVC and fabrics in the direct sun or in open heat sources, this leads to a loss of elasticity and strength.
Frequently Asked Questions (FAQ)
Can I strengthen the standard hinged transom on my own?
Yes, it is possible, but it requires caution. Usually reinforcement is made by installing additional wooden linings or metal corners. However, it is important not to disturb the balance of the boat and not to damage the fabric of the cylinders with sharp edges of metal.
What is the maximum weight of the engine can withstand a standard PVC boat?
Standard two-seater boats are usually designed for engines up to 5-8 hp (weight 20-25 kg). Triple and larger models with glued transmessel can carry engines up to 15-18 hp (weight up to 40-45 kg).
Why does the engine break even when the screws are tight?
Most often, the reason is vibration, which gradually releases the fastener, or in the impact of the screw on the obstacle (log, bottom), which creates an instant load exceeding the friction force of the strubcines.
Do I need to lubricate the transom screws before installation?
Yes, it is recommended to use graphite or silicone grease for threading, this will prevent metal parts from boiling and make it easier to unscrew after prolonged contact with water. Do not use solidol or litol, as they are washed out and can contaminate the water body.