Operating an inflatable boat in bad weather or in hot sun requires the protection that only a well-designed chassis can provide. The basis of the entire structure, the bearing skeleton that determines its strength, wind resistance and durability, are arcs, and it is the quality of these elements that determines whether your house will withstand the gusts of wind or will form at the first storm warning.
Many PVC boat owners make the mistake of thinking that the fabric is the main thing and the frame can be made from improvised materials, a misconception that often leads to breakdowns at the most inopportune moment. Arcs for awning They're under tremendous stress, constant vibration, resistance to airflow, and the weight of wet fabric, and the wrong choice of material or geometry can turn a comfortable walk into a fight against a collapsing shelter.
In this article, we will discuss in detail which materials are best suited to create a frame, how to calculate the necessary dimensions and avoid typical installation errors, why the rigidity of the profile is more important than its thickness, and how to turn a standard awning into an aerodynamically stable structure that can withstand difficult swimming conditions.
Materials of fabrication of the frame: aluminum against fiberglass
Material selection is a fundamental step in the design of a running tent, and two major solutions dominate the market today: aluminum and fiberglassEach of them has its own strengths and disadvantages that must be considered before buying or manufacturing.
Aluminum arcs are typically made from 20 to 32 mm diameter round-section pipes, and their main advantage is their high rigidity and ability to hold shape under load. Aluminum is not afraid of moisture, lightweight and resistant to corrosion, especially if anodized alloy is used. However, such arcs have one significant disadvantage: when hit hard or critically overloaded, they can deform, and it will be almost impossible to straighten them back.
Fiberglass has a unique resilience, and unlike metal, it acts as a spring, absorbing gusts of wind, and if the load exceeds the strength limit, fiberglass breaks but doesn't bend, making it a great choice for removable spider awnings, where flexibility is important. fiberglass They can lose their properties under the influence of ultraviolet light over time, if they do not have a high-quality protective layer.
It is also worth mentioning steel pipes, which are sometimes used in homemade structures, and although steel is cheaper, its weight and rust exposure make this option unsuitable for lightweight inflatable vessels. Specific gravity The design directly affects the stability of the boat, so every extra kilogram on the roof can become critical when rolling.
Geometry and dimensions: calculation of optimal height and width
The right geometry of the arc determines not only the appearance of the awning, but also its functionality. A tent that is too low will press on the shoulders of the boat, and a too high one will turn into a sail that will carry the boat off course even in low winds.
When calculating the width of the arc, it is important to consider not only the dimensions of the cylinders, but also the method of attachment. The arc should rely on transmutor or nose cans, or on special stops fixed on the cylinders. The distance between the points of support should be such that the arc is in light tension, but does not create excessive pressure on the arc. PVC boats.
The optimum height of the awning above the seat should be at least 90-100 cm for comfortable accommodation of an adult in a life jacket.
The shape of the arc also matters. Arched arcs provide better water runoff from the roof of the awning, while broken structures (from straight stretches) are easier to make, but create pockets to accumulate water. compound-arcMake sure that the connecting elements (internal inserts) are of sufficient length to prevent backlash.
For high-speed running awnings, it is recommended to use rear-facing arcs, which allows for airflow to be redirected upwards, reducing drag and the risk of sailing. Direct vertical struts work worse and require more frequent maintenance of the anchorages.
Methods of attaching arcs to the boat hull
The reliability of the arc attachment is a safety issue: in the event of a rollover or a sharp maneuver, the frame should not break apart or damage the cylinders of the boat. There are several basic fixation methods, each of which has its own features of installation.
The most common option is the use of squirrelsThese are special sites that are mounted on rigid cans, the arc is inserted into the socket or fixed with a clamping, and it is important that the site has a soft coating or pad, so that the PVC does not rub when vibrating, the fastening should be rigid, but allows rapid dismantling.
⚠️ Warning: Never attach the awning arcs directly to inflatable tubes with ropes or slings without rigid spacers. This will cause local cloth squeezing and can cause a tear when stretched!
The second popular method is to insert the lower ends of the arcs into special pockets sewn to the awning itself, which are then fixed on the sides of the boat, which is good for temporary shelters, but less reliable when going on planing. metal-glass, welded or glued to a transom board.
☑️ Checking the reliability of anchorages
The third option is a spider system, where the arcs are not rigidly bound to the boat, but are held by stretching the fabric and placing the support on the side, which is convenient for storage, but requires perfect cutting of the fabric, and any error in size will lead to sagging or, conversely, to rupture of the seams.
Structural reinforcement and wind resistance
Even the strongest arcs can't withstand the elements if the awning isn't designed aerodynamically, and the main problem with running awnings is the sail effect, and when you get under the canopy, the wind creates a huge lift that can flip a light boat or rip out the anchorages.
To increase wind resistance, additional stretches and stretches must be used. Windbreakers We have special valves in the front of the awning that allow some air to pass through or flow around the structure, reducing pressure, and it is also important to ensure that the joints between the arcs and the fabric are sealed so that the wind does not inflate the awning from the inside.
| Enhancement element | Materials | Function | Place of installation |
|---|---|---|---|
| Wind ribbon | PVC 600-850 g/m2 | Load distribution | Tent perimeter |
| Stretching (storm trap) | Sling 25-30 mm | Fixation from uplift | From arc to rim boats |
| Stiff sleeve | Teflon/Caprol | Friction protection | Contact points of arc and tissue |
| Additional arc | Aluminum d20 mm | Prevention of sagging | Central part of the span |
Special attention should be paid to the connections of composite arcs. If you use telescopic or collapsible structures, make sure that the locks (buttons, screws) have reliable protection against spontaneous unwinding. Vibration on water can weaken any connection if it is not lawful.
The secret of a quiet tent
Whistling wind in tight strings or thin cables can drive you crazy in a few hours, and to eliminate this effect, use spiral wind generators (whistle) on stretchers or wrap the cables with special violin tape that extinguishes the vibration.
Caring for the frame and prevention of breakdowns
The durability of awning arcs depends not only on the quality of the material, but also on the correct care. Aluminum, despite its resistance, is susceptible to oxidation at scratch sites, especially in salt water.
After each operation, especially in seawater, the frame must be washed with fresh water, which removes the salt, which is the main enemy of metal compounds and adhesives. Conservation In winter, it requires a complete drying of all elements to avoid the appearance of mold at the junction of fabric and metal.
⚠️ Warning: Do not keep awning arcs twisted or bent for a long time, which leads to "material fatigue" and microcracks that can cause sudden breakage on the water.
Check the lubrication status of the movable joints regularly. Silicone lubricant is great for aluminum pipes, which does not collect sand and dirt. If you notice that the arc has started to walk at the junction, immediately replace the sealing sleeves or add a fixing element.
When transporting a boat assembled (which is not recommended, but sometimes necessary), make sure the arcs do not touch the sharp edges of the translat or motor. surface from mechanical damage.
Self-Manufacturing vs. Prepared solutions
The owner of a boat often faces a dilemma: buy a ready-made set of arcs or make them yourself. Flagship, Poseidon) ensure compatibility with the model; they already have the geometry and the mounting units ready.
Self-manufacturing gives you freedom to create and to take into account individual needs. You can make the awning taller, wider or reshape the arcs for better aerodynamics. But it requires metal skills, a bend and accurate calculations. A mistake of a few centimeters can make the awning unusable.
Ready-made arcs are a guarantee of compatibility and time saving, and homemade arcs are an opportunity to create an ideal awning for unique tasks, but requiring an engineering approach.
If you decide to make arcs yourself, use quality rental. Pipes for water supply will not work — they are too heavy and rust. Look for aviation aluminum or special alloys for shipbuilding. Also don't skimp on accessories: cheap carbines and fixers can fail at a critical moment.
Ultimately, the choice depends on your skills and budget, and for most users, the best option is to buy a quality, customized kit (strengthening mounts, adding stretch marks), which will provide a balance between reliability, cost and time.
Frequently Asked Questions (FAQ)
Can I use arcs from one boat manufacturer on another?
Most of the time, no. The geometry of the cylinders, the distance between the banks, and the shape of the transom are different from one manufacturer (and even from one brand model), installing incompatible arcs can cause the awning to skew, leakage to the boat, and even damage, and can only be installed if the mounting system is completely redesigned.
What is the best arc diameter for a boat 3.5-4 meters long?
For boats of this size (for an outboard motor 10-20 hp) is optimal is the diameter of the aluminum pipe 22-25 mm. for more powerful engines and speeds over 40 km / h, it is recommended to use reinforced arcs with a diameter of 28-32 mm with additional spacers.
How to prevent condensation inside the awning when using aluminum arcs?
Aluminum has a high thermal conductivity, so when temperatures drop, condensate actively forms on it, which drips inside. You can solve the problem by wearing special covers made of foamed polyethylene or fabric on the arcs, or treating them with a thermal insulating coating.
Do I need to remove the awning when driving at high speeds?
The awning is designed for use on the go, but when going to planing and gaining maximum speed, the wind load increases sharply. If the awning does not have a special aerodynamic shape and reinforced mounts, it is better to lower or remove it to avoid the risk of turning the boat or breaking the frame.