Proper inflatable floor pumping is the foundation of safety and comfort on the water, and many boat owners underestimate the importance of accurate performance, relying on simple "touch" or "to the point." hardness It directly affects the driving qualities of the vessel and its stability on the wave.
In this article, we will discuss all the nuances of working with low pressure air cylinders (LDPA), you will learn why the pressure gauge indicators change from time to day and how to prevent critical errors that can lead to deformation of the case. PVC materials They have a unique elasticity, but require strict compliance with the operating regulations.
Ignoring the manufacturer's recommendations often leads to premature wear of the seams and loss of shape of the vessel. boat It has been in service for many years, you need to understand the physics of the processes occurring inside the cylinders when external conditions change.
Why it is important to follow the rules of pumping
The low-pressure inflatable floor (LDPB) acts as a keel and ensures the structure is rigid, and if the pressure is insufficient, the bottom will sag under the weight of passengers and equipment. hydrodynamic deterioration: the boat will start to glid worse, fuel consumption will increase, and the move will become rolling and unpredictable.
On the other hand, pumping cylinders in hot weather carries even more serious risks: the air inside the closed volume expands when heated, which can cause joints to rupture or warp bulkheads. The critical threshold for most PVC materials is an excess of working pressure by more than 20-25%.
Well-pumped bottoms turn soft shells into hard platforms, which is especially important when you're installing them. outboardBecause the transom beam has to be rigidly supported, otherwise there is a cruising transmutant effect, which is dangerous for the control.
Standard pressure values for different types of cylinders
PVC boats are designed to be divided into power cylinders (board) and bottom. The sides typically use pressures in the range of 0.2-0.25 atmospheres, enough to provide buoyancy and spray protection, while maintaining some elasticity to mitigate the shocks to the wave.
The inflatable floor is a very different situation, where it takes a lot more pressure to create a rigid plane, and the standard range for BND is between 0.4 and 0.6 atmospheres (or 40-60 kPa / 0.4-0.6 bar). AirDeck They can withstand up to 0.8-1.0 atmospheres, but this is rare.
It is important to understand the difference between the units of measurement. On pump and pressure scales, values can be given in bars, atmospheres (atm), or kilopascals (kPa). For household purposes, 1 bar ≈ 1 atmosphere ≈ 100 kPa can be considered.
Always use a pump with a built-in pressure gauge or connect a separate measuring instrument. Visual assessment of the hardness of the side is often misleading, especially in windy weather.
Effects of Air and Water Temperature on Pressure
The physical laws are inexorable: gas expands when heated, and compresses when cooled. If you pump the boat in the morning in cool weather (+15 ° C) to 0.5 atmospheres, then by noon, when the sun warms the black or dark blue side to +40 ° C, the pressure inside can rise to 0.7-0.8 atmospheres.
This is called thermal expansion, and in the enclosed volume of the balloon, it puts an excessive load on the seams, which is why experienced boaters advise that you do not need to be able to do this. undersize When assembled in the shade or in the morning, leaving a reserve for air expansion.
The reverse happens when you go out, and if you get a boat pumped up in a warm garage and it gets into cold water (+10°C), the pressure drops dramatically, and the bottom becomes soft, and you have to make it. surge on the water or on the water (if the design permits).
⚠️ Warning: Never leave a fully pumped boat in direct sunlight unattended, and the pressure can rise so much that the valves start to blow air, or, in the worst case, the seam will burst.
Table of pressure standards depending on temperature
So, so you don't have to do complicated calculations on Gay-Lussac, we've developed a reference table that will help you navigate what pressure you want to put on the pressure gauge when pumping under different conditions.
| Pumping temperature | Expected operating temperature | Recommended pressure (atm) | Note |
|---|---|---|---|
| +10...+15°C | +25...+30°C (sun) | 0.35 - 0.4 | Leave the margin for expansion |
| +20...+25°C | +25...+30°C (sun) | 0.45 - 0.5 | Standard pumping. |
| +25...+30°C | +30... +35°C (heat) | 0.4 - 0.45 | Control overheating |
| +10...+15°C | +5...+10°C (water/shadow) | 0.5 - 0.6 | Refrigeration compensation |
The data in the table is averaged for most models of boats with the bottom of the NDND. product-passportSince the density of the fabric and the design of bulkheads may differ from manufacturer to manufacturer.
What to do if the boat overheats in the sun?
If you find that the boat left in the sun has become "stone" and the pressure is clearly higher than normal, do not open the valves abruptly. Cover the boat with a wet awning or blanket and wait 10-15 minutes until the temperature inside the cylinders is equal to the surrounding temperature, only after that blow the excess air to normal.
The algorithm of proper pumping of the boat
The process of bringing the craft into operation should be systemic. Chaotic pumping of one or the other cylinder will cause distortion and stress in the joints. Follow the proven sequence of actions.
☑️ Pumping procedure for PVC boat
First, the main buoyancy cylinders are always pumped in about half, so that you can straighten the folds of the material and align the geometry, then you pay attention to the bottom, you need to pump it last, or you need to bring it to condition after the sides, to ensure maximum rigidity.
Use a pump with the right performance. For bulk boats (3.2-3.6 meters), a hand-held frog may not be effective at creating high bottom pressure. foot-pump Or an electric compressor with auto-stop function.
After the initial pump, leave the boat for 10-15 minutes. PVC has the ability to stretch under load. The pressure will inevitably drop, and you will need a final test. pumping up to nominal values.
The rule is: shape first, pressure later. Don't try to pump the balloon to 0.5 atmospheres right away if it's still folding, and that will create local stretch points.
Frequent errors and precautions
One of the most common mistakes is using car compressors without pressure control. The powerful airflow heats the balloon quickly, and the lack of an accurate pressure gauge leads to pumping. Always monitor the process.
It's also dangerous to pump a boat over your eyes, especially if you're changing operating conditions, and what was normal fishing on an overcast day will become critical for a walk at noon. Manometer - your best friend in this case.
Remember to check the valves. Sometimes the air poisoning is not because of the hole, but because of a grain of sand that enters the valve seal, and regular cleaning and grease with silicone will prolong the life of the valve valves.
⚠️ Warning: Never use open flames or powerful heat guns to "stripe" folds in the cold. Local overheating can melt PVC fabric or weaken the adhesive seam.
inflatable floor maintenance and storage
Properly storing a boat prolongs its life no less than proper operation. After the season, the bottom of the NDNDM should not be left pumped "to zero" or, conversely, in a compressed state under heavy loads.
Before packing, the boat must be thoroughly washed from sand and silt, dried and folded in free loops. Sharp cracks in the cold can lead to microcracks in the material. Use talc to treat the surface so that the layers of fabric do not stick together.
Check the pressure in the canned boat regularly (every 2-3 months) to help you notice a slow leak and identify the problem before the next season. Repairs It is easier to do in the workshop, while the hole is small.
Can I keep my boat full in the winter?
Keeping a fully pumped boat in an unheated room in winter is absolutely impossible. Temperature changes will lead to pressure surges and condensation inside, which will cause mold and glue degradation.
Frequently Asked Questions (FAQ)
Can I pump a boat with a car compressor?
Car compressors often do not have accurate pressure gauges for low pressure (up to 1 atmosphere) and can overheat, it is better to pump the main volume manually, and use the compressor only for final pressure, constantly monitoring the parameters.
Why does the pressure drop in the boat after pumping?
It's a normal physical process. PVC material has the ability to stretch under pressure. 15 to 20 minutes after pumping, the volume of the balloon increases slightly, and the pressure drops. You just have to pump the boat back to normal before you go out.
What pressure is critical for a joint to break?
For most PVC boats, pressures above 0.8-0.9 atmospheres are considered critical. However, seams may not withstand less pressure if they have been damaged or glued together in a faulty manner. Do not experiment with limit values.
Should I shoot a boat when it is in the shade?
If the boat is assembled in the heat and then brought into a cool room or shade, the pressure will drop, and you don't need to put anything out. You only need to blow the air if the boat was under the sun and the pressure has risen above normal.