Operation of a small vessel is impossible without reliable fastening of the power plant. Stand for an outboard motor It is the quality of this unit that determines how well the screw will keep in flow and whether you lose expensive equipment during a storm or a failed maneuver. Owners of PVC inflatable boats and metal "kazak" often face the need to refine the standard transom or completely replace it to install a more powerful unit.
Incorrectly selected or mounted design can lead to critical consequences, up to the sinking of the boat. transom board It's a huge stress, vibration, surge and weight of the engine. If you're planning to upgrade your boat, it's important to understand the difference between factory solutions and homemade crafts. In this article, we'll look at all the nuances of choosing, manufacturing and installing a reliable support for your engine so that every fishing trip ends safely.
Safety is a big issue here, and many newcomers underestimate the importance of safety. transomatureIt's a "maybe" but water doesn't forgive mistakes. The critical parameter is the inclination angle of the daydvut, which directly depends on the height and shape of the transom board. The wrong angle will lead to cavitation, overheating of the engine and increased fuel consumption, so the design or purchase of the rack must be approached with engineering precision, considering not only the power of the engine, but also the material of the boat hull.
Design features and types of transom boards
All transomach boards can be divided into several categories depending on the material of manufacture and the method of attachment. For PVC inflatable boats, plywood inserts are most often used, which are inserted between cylinders. transom plate It should have high strength for bending and compression, since the weight of the motor is distributed unevenly.
Special attention should be paid pendantThese are removable structures that are attached to the sides of the boat with special brackets, which allow you to install motors of greater power than the standard transcense. However, such systems require very reliable fixation to exclude backlash. Vibration transmitted to the hull can quickly destroy the seams of inflatable tubes or loosen rivets on a metal boat.
There are also specialized solutions, such as rotary and folding transes, which are convenient for storage and transportation, but have more moving parts that require maintenance. The locking mechanism In such models, it should be made of stainless steel or brass, resistant to corrosion. The use of conventional black steel is unacceptable here, since salt water will quickly turn the fasteners into rusty debris.
When choosing between a solid and a composite structure, remember to maintain. If you often go to remote places, the ability to quickly replace a damaged element can save your expedition. The simplicity of the design is often the key to its reliability. Complex hinge systems are beautiful, but in extreme conditions, a simple but thick plywood board with a quality coating can be more reliable.
Materials for self-manufacturing
If you decide to do so boat-stack The choice of material becomes a determining factor in success. The basis for PVC squirrel boards is traditionally PVC moisture-resistant plywood. It is the only material that combines the necessary strength and affordable cost. FC conventional plywood will quickly dissipate from constant contact with water, even if it is carefully painted.
For metal boats or reinforced structures, aluminum sheets with a thickness of at least 4-5 mm are often used. Aluminum alloy AMG (aluminum magnesium) is very corrosive and highly impact-resistant, and steel is not recommended because of its weight and rust exposure, even if it has a good paint coating, and any scratch on the steel transmunus will be a corrosion hotbed that will weaken the structure over time.
Plywood coatings are a separate topic of conversation. In the past, fiberglass and epoxy were used a lot, but today's polyurethane paints and varnishes are better, they're more elastic and they don't crack when they hit. It's important to treat not only the planes, but also, most importantly, the planes. plywoodIt is through the slices of layers that moisture penetrates in the fastest way, causing swelling and rotting.
Use plywood with a thickness of at least 12 mm for motors up to 5 hp and 18-24 mm for motors 10-15 hp and above.
You can also add metallic linings to the engine attachment, especially for powerful engines that can push through wood when rods are tightened, and aluminum or plastic linings can spread pressure over a larger area, keeping the transax board intact for years to come.
Step-by-step instructions for making transoms yourself
The process of building a reliable engine support requires precision and adherence to technology. Below is a sequence of steps that will allow you to make a durable structure. Take your time and carefully check each step, as it will take much longer to rework the finished product.
- 📏 Take accurate measurements from your boat, given the curvature of the cylinders or the side.
- 🪚 Cut the workpiece from the plywood of the FSF or aluminum sheet according to the template.
- 🧪 Treat all surfaces and especially the ends with an antiseptic and primer.
- 🎨 Apply 3-4 layers of varnish or paint with intermediate drying and grinding.
When cutting material, it is important to use sharp tools so as not to damage the structure of the wood or deform the metal. For plywood, the best fit is an electro-cloak with a saw for clean cutting or a circular saw with a hard alloy disk. If you work with aluminum, use a metal hacksaw or a Bulgarian with an aluminum disk to keep the edges smooth.
☑️ Tran quality control
The final assembly involves the installation of fasteners. Plywood trunks often use glued sleeves or through bolts with wide washers. Fastening It should be made of stainless steel grade AISI 304 or AISI 316. Conventional fasteners will rust in the first season, and you risk losing the engine. All holes should be carefully sealed to prevent moisture from entering the material.
⚠️ Attention: When drilling holes in plywood, be sure to use a drill with sharp sharpening and low revs, so as not to "rag" the edges of the hole, which will further lead to rapid destruction of the material around the fastener.
Table of selection of thickness of the transmuted board
The right choice of thickness of the material depends on the weight and power of the engine being suspended. Using a board that is too thin will lead to its deformation, and an excessively thick one will weight the stern of the boat, which will affect the driving performance.
| Engine power (hp) | Motor weight (kg) | Materials | Recommended thickness (mm) |
|---|---|---|---|
| 2 - 5 | 15 | FSF phanera | 12 - 15 |
| 6 - 10 | 15 - 30 | FSF phanera | 18 - 21 |
| 10 - 15 | 30 - 45 | Phanera FSF/Aluminum | 24 - 28 |
| 15+ | 45+ | Aluminum/Reinforced plywood | 30+ |
The data in the table is averaged. inflatable floor boats (BBBBs) are loaded differently than in hard floorboard boats. In any case, safety margin is never superfluous. If you're in doubt, it's better to choose a thickness of 1-2 mm more than the design is at risk.
Effect of weight on driving performance
The weight gain on the transom requires the boat to shift its center of gravity forward, and if not, the boat will start digging its nose, causing the cockpit to flood with water and slow down.
Installation and adjustment of the inclination of daydvut
After cross-board And it's ready and mounted on the boat, and the engine assembly phase is coming in, and the key here is to set the right inclination of the daywut relative to the bottom, and the standard angle is 0 degrees (vertically), but it can vary depending on the design of the boat and the load.
To adjust the angle of inclination, special holes in the engine rods or additional gaskets (wedges) between the motor and the transom are used. Engine tilt It affects the boat's differentiation, and if the lower unit is too backward, the boat's nose will be upwards, which makes it less visible and manageable, and if it's too forward, it will peck at the boat, increasing the water resistance.
- 🚀 At full gas, the water jet should exit parallel to the surface of the water.
- 🌊 The anti-cavitation plate should be 1-2 cm below the bottom of the boat.
- ⚓ When installing, make sure that the motor does not touch water when reversing.
Incorrect angle adjustment can lead to cavitation, which boils water around the propeller to form vapor bubbles, which dramatically reduces traction and can damage the propeller blades, so after installation, be sure to conduct sea trials on the safe part of the reservoir, observing the behavior of the boat and the operation of the engine.
The ideal angle of inclination is achieved when the boat is horizontal and the anti-cavitation plate is parallel to the surface of the water.
Care, maintenance and typical mistakes
Even the best quality. boat-stack After each foray into the water, especially in salt water, the structure needs to be washed with fresh water, which will help wash away salt, sand and aggressive chemical compounds that can destroy the protective coating.
Once a season, it is recommended to conduct a revision of the fasteners. Check the tightening of the bolts, the condition of the washers and nuts. Vibration is the main enemy of all connections. Loctite) will help to avoid spontaneous unwinding of the fastener while driving.
⚠️ Warning: Never leave the hanging motor on the transom during long parking or winter storage, which puts a constant strain on the board and can cause it to deform or break the mounts.
A typical mistake is to ignore minor damage to the coating, a paint chip or scratch on the varnish is an open gate for moisture, repairs must be done immediately, cleaning the damaged area and applying a new layer of protective composition, and you should not overload the transom with motors that exceed the manufacturer's recommendations, which is dangerous not only for the transom, but for the entire structure of the vessel.
Timely lubrication of moving parts (if any) and UV protection will extend the life of your rack. Use special sprays to protect PVC and rubber if the transom comes into contact with cylinders. A comprehensive maintenance approach will ensure you will have many years of safe and comfortable operation.
Can you use conventional plywood for transom if it is well painted?
Regular plywood (PC) has a water-resistant adhesive layer, even the best paint will eventually give a microcrack, moisture will penetrate and plywood will begin to dissipate. Use only PSF or marine plywood.
What is the maximum weight of the engine will withstand an inflatable boat?
This depends on the density of PVC fabric and the design of the transom, and typically for 2-3-person boats the limit is 10-15 hp (about 35-45 kg), exceeding this weight can lead to deformation of the aft part and loss of buoyancy.
Do I need to remove the engine when transporting a boat in a trailer?
It is advisable to remove the load on the transom and avoid vibrations when driving on the road. If removal is not possible, use transom wheels and securely lock the motor so that it does not hit the transom.
How often should I change the PVC boat?
When properly operated and maintained, a high-quality board from the FSF lasts 5-7 years or more, signs of wear are swelling of the ends, cracks in the lacquer layer and the appearance of backlash in the places where the motor is attached.