Operating a low-pressure inflatable boat requires the owner to understand the basic physical processes that occur inside the cylinders. Many beginners mistakenly believe that the more inflated the boat, the better it will behave on the water, but this misconception can lead to damage to the seams or deformation of the hull geometry. The right balance of rigidity and elasticity of the material is the key to long service of your body. fly-boat.
The question of how much pressure PVC NDND should be in a boat doesn't have the only universal answer in absolute numbers, without reference to ambient temperature: the pressure inside the balloon is dynamic and directly depends on the heating of the gas by the sun or cooling at night, and ignoring this fact often causes tissue to break in the summer heat or the appearance of folds when you go out on the water in the morning after a cold night.
In this article, we will discuss in detail the technical details of operating inflatable floor boats, consider the dependence of the gauge on degrees Celsius and give clear instructions for preparing for the water. Understanding these processes will allow you to avoid emergencies and enjoy fishing or cruising without too much concern for integrity. polyvinyl chloride design.
Physics of the process: the dependence of pressure on temperature
The basic law that every PVC boat owner should know is that when heated, the gas expands, increasing the pressure in a closed volume, and when cooled, it shrinks. This means that if you pumped the boat in the morning at +15 ° C to the recommended 0.25 atm, then by noon, when the sun warms up the black cylinders to +40 ° C, the pressure inside can rise to a critical 0.35-0.4 atm. score-point It's mandatory during the day.
There is a common mistake when users pump the boat "by eye" or "to the point" in an air-conditioned room and then take it out in the sun, in such cases, the material can not withstand internal stress, and there are breaks at the seams or valve connections, and vice versa, if you pump the boat in the evening when it becomes cool, in the morning it will look sluggish and "sloppy", which will adversely affect the performance.
⚠️ Warning: Never leave a fully pumped boat in direct sunlight unattended. If you can't put too much pressure on, make sure to create a shadow with an awning or turn the boat upside down to reduce heating of the black surface of the bottom.
To understand the processes accurately, it is important to consider that different gases behave differently, although in practice we most often use air. Air humidity also plays a role, but to a lesser extent than the temperature gradient. gauge High quality, as cheap Chinese analogues often give an error of up to 0.05 atm, which is significant for low pressure values in boats.
Why do black boats heat up faster?
Black absorbs almost the entire spectrum of solar radiation, turning it into thermal energy. Light boats (gray, camouflage with a predominance of light colors) heat less, but the difference in pressure will still be noticeable.
Standards for different elements of the boat
The design of the boat with NDND is more complicated than the model with plywood peyol, because here the bottom itself is a load-bearing element of rigidity. The pressure in the inflatable floor sections is usually lower than in the onboard cylinders, but the requirements for uniformity of load distribution are higher. If the sides can withstand higher values, then the pumping of the bottom will cause it to swell upwards ("domel"), which will make the landing in the boat unstable.
Standard factory recommendations for most manufacturers (such as: Flagship, Solar., hunterHowever, always consult the product passport as the density of the fabric (e.g. 900 g/m2 or 1100 g/m2) affects the strength specifications.
| Element of the boat | Recommended pressure (atm/bar) | Maximum pressure (atm/bar) | Features |
|---|---|---|---|
| Onboard cylinders | 0.25 – 0.30 | 0.35 | Basic buoyancy |
| inflatable floor (NDB) | 0.15 – 0.20 | 0.25 | Flat rigidity |
| Keel (if any) | 0.15 – 0.20 | 0.25 | Improvement of course |
| Inflatable transom | 0.20 – 0.25 | 0.30 | Motor attachment |
It is important to understand the difference between the units of measurement. On pump gauges, the scale is often marked in PSI (pound force per square inch) or kPa (kilopascal). To translate: 1 atm ≈ 1 bar ≈ 14.5 PSI ≈ 100 kPa. Confusion in the units of measurement is a common reason that users accidentally pump their own devices. PVC boats They are several times higher than normal, believing that they pumped only 0.2 "units".
The optimal pressure for the sides is 0.25 atm, for the bottom of the NDNDM - 0.15-0.20 at a temperature of +20 ° C. Exceeding these values is dangerous for the integrity of the seams.
The algorithm of proper pumping of the boat
The process of bringing the boat into operation must be systematized to avoid distortions and uneven tension of the fabric. First, the main cylinders are always pumped, then the keel (if it is separate), and only lastly, the inflatable floor, this sequence is due to the fact that the boards set the general geometry, and the bottom only fills the inner space, resting on them.
Use a back pressure valve pump or watch the process carefully so that the air does not come out when the piston position changes. For the final fine-tuning, high-pressure foot or hand pumps are ideal for feeling the air resistance. Electric pumps are good for primary pumping by 80-90%, but the finishing pressure is better controlled mechanically.
- 🌊 Spread the boat on a flat surface without sharp objects and debris.
- 💨 Pump the cylinders to a state of elasticity, but not to full rigidity (about 0.15 atm).
- ⏳ Leave the boat to lie down for 10-15 minutes to straighten the folds of material.
- 📈 Bring the pressure in the sides to 0.25 atm, and in the bottom of the NDND to 0.15-0.20 atm.
⚠️ Warning: Do not use car compressors for the final stage of pumping without a pressure gauge. They deliver air very quickly and can instantly create excess pressure that will tear the seam before you notice the change in shape of the cylinder.
After pumping, be sure to check all the valves for leakage. Apply soap solution on the open valve and press on the balloon - the absence of bubbles will confirm the shut-off mechanism. transmesseMake sure it is pumped symmetrically, otherwise, when installing the engine, there may be a skew leading to the roll of the vessel.
☑️ Checking the boat's readiness
Exploitation in the heat and cold: seasonal nuances
Summer maintenance requires special attention. As mentioned, the sun is the main enemy of a pumped boat. If you go out in the morning when it was cool and pumped the boat to normal, by 12-14 p.m., be sure to check the pressure. You'll probably have to blow some of the air to compensate for the expansion of the gas. Ignoring this rule is a direct route to repair. polymer.
Winter fishing or boating in the cold season dictates different conditions: in the cold, PVC cloth blubs, becomes less elastic, and the pressure inside drops. In such conditions, the boat can be pumped to the upper limit of normal (0.3 atm), but this should be done carefully. Sharp blows on the ice or rocky shore of a frozen boat can lead to microcracks that will manifest later.
The storage of the boat also depends on the season. If you leave the assembled boat in the garage or in the country, take into account the night temperature changes. In winter, it is better to keep the boat slightly underperformed or even deflated, because in the cold the material loses its strength to bend. In summer, in a closed unventilated room (for example, a metal container), the boat cannot be kept categorically - the greenhouse effect will heat the air inside to critical values.
Diagnosing problems through pressure
The behavior of the boat on the water can tell you a lot about the correctness of its pumping. If you notice that the boat has become worse to keep its course, "scour" or excessive rolling, check the pressure in the keel and nose. Lack of keel rigidity leads to loss of course stability, especially when moving against the wave or against the current.
If the bottom of the boat NDND began to resemble a pillow and fall out into the cockpit, this is a sign of pumping the bottom relative to the sides or, conversely, insufficient pressure in the sides that “embrace” the bottom. Visual inspection of the side line is also informative: at the right pressure, the seams should be stretched, but not whitened from overstrain of the cord threads.
- 📉 The boat became sluggish on the move - check the pressure in the keel part.
- 🌪️ The boat is blown aside in the wind - perhaps one of the sides is pumped.
- 🛋️ The bottom is arched upwards - excessive pressure in the sections of the NDND.
- 💧 There is water in the cokpite - check the tightness of the valves and joints under pressure.
A common problem is material fatigue. Over time, PVC can stretch slightly in places of greatest tension. If you feel that the boat is holding pressure worse than a new one, you might want to add 0.01-0.02 atm over the norm, but only if the material allows and does not look thinned. However, more often the cause lies in temperature fluctuations or micropunctures.
Take a rule to carry a compact pressure gauge nozzle. It takes up minimal space, but allows you to check the condition of the boat in seconds and avoid problems on the water.
Maintenance and care of inflatable elements
To keep the NDND boat under pressure for a long time, you need to monitor the condition of the valves. Sand, dust and small debris, getting into the valve mechanism, violate the leakage. Rinse the valve joints regularly with clean water and check the rubber seals for cracks or denting.
After each operation, especially in salt water or water with a high content of silt, the boat must be washed. The salt and dirt act as an abrasive and a chemical reagent, gradually destroying the top protective layer of PVC. This leads to microcracks through which air can escape, albeit slowly, but constantly reducing the air. rigidity.
⚠️ Warning: When washing a boat, do not use aggressive chemicals, gasoline, acetone or solvents. They destroy the polyurethane impregnation of fabric. Use only special PVC care products or ordinary soap solution.
Drying before packaging is a critical step. If you pack a wet boat, the molding process will begin inside, which will weaken the fabric base. Also, water in the folds when frozen in winter can damage the material structure. Always dry the boat in the shade, as wet boat drying in the sun is also undesirable due to uneven warming.
Frequently Asked Questions (FAQ)
Can I pump a PVC boat with a compressor from a car?
Car compressors can only be used for primary pumping (up to 70-80% of the volume), to bring the pressure to operating values must be manual or foot pump with a pressure gauge. Car compressors often provide too powerful flow, not allowing you to control the time of reaching the desired pressure, which can rupture the seams.
Why does the boat lose pressure at night?
It's a normal physical process. At night, the temperature drops, the gas inside the cylinders shrinks, and the pressure decreases, in the morning, when the sun starts to warm the boat, the pressure will return, and if the boat deflates completely overnight even in warm weather, there is a leakage (puncture or valve malfunction).
What pressure is safe for a NDND boat in winter?
In winter, the material becomes stiff. The recommended pressure remains within 0.25 atm, but should be pumped gradually, allowing the material to warm up or adapt. It is critical to avoid impact loads on a frozen boat. Some anglers recommend keeping the pressure just below the maximum (about 0.22 atm) to compensate for possible differences.
How is the pressure in a boat with NDND different from a boat with floorboard?
In hard floorboard boats (plywood, aluminum), only float cylinders hold the main pressure. In NDNDB boats, the bottom is also inflatable and requires its pressure (usually less than the sides) to create a rigid plane. An error in pumping the bottom of NDNDM causes the entire boat to be geometry disrupted, whereas in a SDB, this affects only comfort.
Do I need to bet the boat on the roof of the car?
Yes, it is. When driving, especially in sunny weather, the cylinders are heated by friction against the air and the sun, the pressure inside can increase by 30-40%, it is recommended to blow about 10-15% of the air in front of the road or regularly check and vent excess on the way to avoid rupture.