The process of preparing the boat for launch seems elementary only at first glance, and many owners, especially beginners, make critical mistakes related to the temperature expansion of air or uneven pressure distribution in the compartments. Wrong pumping. It can lead to deformation of the floor, rupture of the seams or, conversely, to the loss of rigidity of the structure at the most inopportune moment.
In this article, we will discuss the physics of the process, the technical nuances of working with valves and the algorithms of actions for different types of boats, you will learn why it is a bad habit to inflate "by eye" and how using a pressure gauge prolongs your life. PVC several times.
The main objective is to ensure operating pressure in 0.2 atmosphere (or passport) in all compartments, taking into account the ambient temperature, and it is compliance with these parameters that guarantees safety and comfort on the water.
Physics of the process: why you can not pump “to the point”
Air is a gas that obeys the laws of thermodynamics, and when you pump a boat in the shade or in a cool garage, and then you take it out into the scorching sun, the internal volume of air starts to grow rapidly. Temperature expansion It can increase the pressure in cylinders by 15-20% in just an hour.
If you initially pump the sides, then in the sun PVC The seams, which are the most vulnerable parts of the structure, can become unloaded and disperse, especially for boats of dark colors (gray, green, black), which heat up faster than light.
But underpumping is also a problem, because sluggish sides don't provide the necessary rigidity, and the boat becomes wobbly, and it blows away by the side wind, and then it's not very rigid. kielson If you have one, it doesn't spread out completely, which degrades driving performance and handling, and when you wave, soft sides can collapse, creating dangerous situations.
Always keep your pressure reserve if you plan to be in the sun, and keep the boat down to 0.1 atmosphere before you leave the shadows.
There's a simple rule: it's better to just under-pump the boat before you leave the house than to pump it on the shore, and in the first case, you just add air in 15 minutes, in the second case, you risk depressurization.
Selection of equipment: pumps and pressure gauges
The quality of the pumping depends on the equipment used. Hand-held foot or piston pumps ("frogs") are good for pumping or small boats, but they require considerable physical effort to fully pump large models. Electric pumps (12V battery or Li-ion) speeds up the process significantly, but often fails to deliver final pressure.
Most electric pumps blow to 0.15-0.18 atmospheres, after which their performance drops to almost zero. So professionals use a combined method: the main volume of air is pumped by the electrician, and the finishing pressure is achieved. high-pressure hand-pump with a built-in pressure gauge.
- 🔋 Battery pumps: Autonomous, comfortable, but heavier and require charging.
- 🚗 Lighting pumps: They are reliable, work on the car, but depend on the length of the cord.
- 🦶 Foot pumps: It’s a classic, timeless, effortful, but full control.
A critically important element is gaugeYou can't rely on sensations ("hard to touch") because the subjective sense of hardness varies with the temperature of the hands and the thickness of the boat material, and only the arrow or the numbers on the instrument will give you an objective picture.
Step-by-step instruction: algorithm of actions
The pumping process must be in a sequence to ensure that the load is evenly distributed to the seams and bottom: first, the cylinders are always pumped, then the inflatable floor (if any), and only at the end - the keel (if the model provides for it).
Start by opening all the valves. Let the boat spread naturally for 5-10 minutes. Then close the valves and start the air supply. At the beginning, make sure that the cylinders are inflated evenly, without skewing. If one side inflates faster, hold it with your hand.
☑️ The algorithm of proper pumping
When the boat takes shape, move to the final stage. Connect the pressure gauge and bring the pressure in the cylinders to the value recommended by the manufacturer (usually 0.2 atm). After that, pump the inflatable floor (if any) to a higher pressure - usually 0.25-0.3 atm, as it experiences load from the weight of the passengers.
The last step is to pump the keel. Inflatable keel It has to be hard like a rock, and it can have pressures of 0.4 to 0.6 atms or higher, and it's the hard keel that keeps the boat stable and stable on the water.
Table of recommended pressure parameters
Other design elements of the boat require different approaches. Below are the average values, but always check your passport. PVC.
| Element of the boat | Recommended pressure (atm) | Feelings of touch | Priority of pumping |
|---|---|---|---|
| Cylinders (board) | 0.20 | Elastic, but pressed with a finger | First. |
| inflatable floor | 0.25 - 0.30 | Hard, not bending under weight | Second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second second |
| Inflatable keel | 0.40 - 0.60+ | Very hard as a tree. | Third |
| Trans inserts | 0.15 - 0.20 | Elastic | Parallelly. |
The pressure of 0.2 atm seems low, but for the area of the sides of a large boat, this creates a huge total force, bursting the structure from the inside.
What is PSI and how to translate?
On some pressure gauges (especially Chinese or American pumps), the scale is indicated in PSI. 1 atmosphere ≈ 14.5 PSI. Accordingly, 0.2 atm is approximately 2.9 PSI. Don't confuse the scales so as not to tear the boat apart!
Work with valves: types and nuances
Modern boats are equipped with valves of different designs. Bravo valves (double-petaled) and spring-valveUnderstanding their work is essential for rapid pumping and tightness.
The double-petal valves have a central movable part; in the lower position (closed), it blocks the air out; in the upper position (open), it allows air out, which is convenient for pressurizing or packaging; when pumped, the airflow presses the petal itself, closing the valve.
⚠️ Attention: Before you start pumping, make sure that the center part of the valve is in the lower (closed) position. If it is raised, the pump will drive air to nowhere, and you will not be able to create pressure.
There's also a valve with a threaded lid, and the lid is an insurance and dirt protection valve, but it's not a pressure retention valve, and you can tighten it after you pump it so that the sand and water don't get into the valve mechanism.
Electric pumps often use special nozzles (adapters), make sure that the nozzle sits tightly in the neck of the valve, if the adapter is chosen incorrectly, it can slip inside the valve or, conversely, do not create leakiness, which will cause some air to escape into the atmosphere.
Typical errors and precautions
One of the most common mistakes is to ignore the surface on which the pumping takes place. To pump a boat on hot asphalt, concrete or sand, you expose the PVC to thermal shock. The bottom heats up instantly, the pressure rises, and the boat can deform before it even goes down.
Use a protective awning or bedding under the bottom during preparation, if this is not possible, try to keep the boat in the shade or constantly flip it over to keep the heat even. Direct sunlight The main enemy of a well-inflated boat.
- 🌡️ Ignoring temperature differences: Pumped in the heat, lowered in the cold - the boat will become soft.
- 🔥 Heating in the sun: A boat left on the shore can burst from overheating.
- 🔪 Sharp objects: Check the site for branches, stones and broken glass.
Another mistake is trying to level the balloons by hitting or pushing the arms very hard when the boat is already pumped, which creates local stress points in the seams, and you need to shape the boat as you build volume while the material is elastic.
The main principle of safety: the pressure in the boat should correspond to the temperature of the environment, not your sensations.
⚠️ Attention: Never use powerful industrial compressors without a gearbox or pressure gauge to pump a boat, which can create excess pressure in seconds, guaranteeing that the seams will break.
FAQ: Frequently Asked Questions
Can I pump a boat with a compressor from a car?
Car compressors can be used, but with great care. Car compressors often develop pressures up to 3-7 atmospheres, which is deadly for a boat (you need only 0.2-0.3). You need a high-quality pressure gauge and constant monitoring. It is better to use specialized PVC pumps with a pressure limiter.
Why does the boat become soft an hour after pumping?
You probably pumped the boat in a warm room or in the sun, and then you lowered it into cold water, and when you cool it, the air compresses, and the pressure drops. That's okay. Just push the boats back to normal, either on the water or just before you descent.
What pressure should be in the inflatable keel?
The keel must be pumped much stronger than the sides, usually to 0.4-0.6 atms and above (to the point, while the pump can be pushed through), it works as a rigid beam, providing stability. Soft keel turns the boat into a doughnut, which is difficult to operate.
Do I need to take air off after fishing?
When you're in a car in the heat, you have to blow some of the air out, otherwise the boat might burst. If you keep the boat in the garage at a stable temperature, you can leave it slightly pumped, but for long-term storage, you better blow it completely to relieve stress from the material.