Installing a hard bottom into an inflatable boat is the first and most important step to turning a simple inflator into a full-fledged floating craft for serious fishing or recreation. It is the hard slate (as professionals call the floor) that gives the body the necessary rigidity, allowing it to stand confidently on its feet, install a more powerful motor and move comfortably along the cockpit. Without a quality floor, the boat behaves like an unstable float, and each row turns into a fight against the inertia of a soft construction.
The choice of material for the bottom is often the subject of fierce debate between fans of classical plywood, fans of light aluminum and adherents of modern composites. Plastic bottom PVC boats have been gaining popularity in recent years due to their absolute durability and durability, but they have their own nuances that you need to know before buying or building it yourself. In this article, we will discuss in detail all aspects of choosing, installing and operating a hard floor.
It should be noted that replacing the standard inflatable floor (NDF) or thin plywood with a stronger material dramatically changes the running specifications of the vessel, increasing displacement, which may require a review of the load capacity, but it significantly improves stability and safety. Polypropylene and polyethylene The high density materials used for such purposes have unique properties that make them ideal for aquatic environments where contact with water occurs constantly.
Advantages and Disadvantages of Hard Plastic Floor
The main advantage of plastic is its complete inertia to water, unlike plywood, which must be constantly dried, lacquered and protected from stratification. polymer You can forget it in the water for the whole season, and it won't happen, it doesn't rot, it doesn't rust (like aluminum in certain conditions), it doesn't require complex maintenance, and it makes plastic sleigh the perfect choice for those who keep the boat assembled or have no conditions for quality drying after every fishing.
But there's a downside to this: Plastic, especially high-quality shipbuilding, can be heavier than thin aviation plywood, although lighter than steel. In addition, in the cold, some plastics become brittle, so operating at extremely low temperatures requires caution. The temperature threshold of fragility of most polypropylene sheets is about -20°C, below which the mechanical strength drops sharply. It is also worth considering that the smooth surface of the plastic can be slippery, which requires additional processing or the use of anti-slip coatings.
An important aspect is rigidity: a thin sheet of plastic without additional reinforcement can bend under the weight of a person, creating a trampoline effect. Therefore, for boats of medium and large size, sandwich structures or profiled plastic are often used, which holds the shape better than a flat sheet, This is especially true for boats longer than 3 meters, where the requirements for floor strength increase proportionally to the area.
⚠️ Attention: Do not use conventional building polycarbonate or plexiglass to make the floor. These materials do not have the necessary impact toughness and when loaded on a kink (for example, when hitting a wave) can crack, creating a dangerous situation with sharp edges and loss of body rigidity.
Comparison of materials: Plywood, Aluminum or Plastic?
To make a good decision, you need to compare the basic specifications of the materials: plywood (usually bakelite or laminated) is a classic, affordable and maintainable, but requires care. Aluminum (often duraluminum) is lightness and strength, but high thermal conductivity (cold to the feet) and the possibility of corrosion in salt water, and plastic occupies a niche “put and forgot”, offering a balance between durability and weight.
Below is a comparison table that will help you decide on the material to upgrade your boat, and the data is averaged for sheets of thickness that provide comparable stiffness.
| Characterization | Plywood (9-12 mm) | Aluminum (AMG) | Plastic (PP/HDP) |
|---|---|---|---|
| Weight (kg/m2) | ~6-8 kg | ~3-4 kg | ~5-7 kg |
| Moisture resistance | Low (requires protection) | High. | Absolute. |
| Impact strength | Medium | High. | Very high. |
| Price. | Low. | High. | Medium |
The choice also includes the way the floor elements are attached to each other, the easiest way to connect the plywood with aluminum profiles or simply join with the overflow of cylinders. Aluminum sheets often require riveting or welding, which is difficult to do at home without skills. Plastic is perfectly cut, and you can use special profiles or even thermal welding to connect it, if you have the right equipment.
Technology of installation and assembly of plastic bottom
The process of installing a hard floor in a PVC boat requires precision and consistency. Improperly stacked sheets can damage the inside of the cylinders or disrupt the geometry of the inflated hull. Before starting work, be sure to clear the cockpit of sand and debris, as any abrasive particles under the hard sheet will work like sandpaper, rubbing the PVC fabric when moving.
The assembly begins with the laying of the nose. The sheets must fit tightly together, but must not rest on cylinders with force, creating excessive stress. For plastic floors, often use a groove-comb system or special connecting profiles made of aluminum that are fixed by screws. It is important to use a fastener with a flat hat and be sure to cover the hats with plugs or glue them so that they do not scratch clothes and tackles.
If you're making the floor yourself from sheet material, you need to make an exact pattern. The shape of the PVC boat cockpit often has complex curves, and right angles are rare here. Use cardboard or cheap sheet material for fitting. Gap. between the edge of the floor and the cylinder must be at least 1-2 cm along the entire perimeter, so that when pumping the boat cylinders do not deform and burst from the pressure of the hard edge.
☑️ Checking before flooring
Pay special attention to fixing the aft part, where the transom liner or the can will be installed for an outboard motor. Here the load is maximum, and any backlash can lead to structural failure. The plastic is well drilled, so you can use additional stops glued to the cylinders (on special glue for PVC) or fixed through stringers, if the design of the boat allows this.
Scream removal and noise insulation
One of the common problems of the hard floor, especially when combined with aluminum profiles, is squeaking. When a boat moves along a wave, or even when a fisherman moves inside a cockpit, rubbing plastic against plastic or metal against plastic creates an annoying sound that spreads very well on the water. It not only reduces comfort, but can also scare fish when fishing in shallow water.
To combat this phenomenon, you need to put damping material between the elements of the structure. linoleum, car-felt They need to be laid at all points of contact of rigid elements: between the floor sheets, between the floor and the cylinders (if there is contact), and also at the places of attachment of cans and transoms.
Secret to a quiet boat
Use a self-adhesive window seal (D profile) that is soft, moisture resistant and perfectly dampens vibrations, paste it on the ends of plastic sheets and on the contact points with aluminum profiles, which will reduce noise by 80%.
Also worth paying attention to the condition of the fasteners themselves: loose screws or bolts start to rattle; regularly check the tightening of joints, but do not drag them to avoid pushing the plastic. Using engrovers or plastic washers under nuts also helps to keep the connection reliable and quiet for a long time.
⚠️ Attention: Do not use water-absorbing materials such as ordinary fabric, foam or untreated wood for noise insulation, and when wet, they will produce odor, rot and extra weight that cannot be quickly dried.
Hard floor care and maintenance
Although the plastic bottom is considered almost indestructible, minimal maintenance is still necessary to extend the life of the entire boat. After each step on the water, especially muddy (silty) or sand water, it is recommended to rinse the floor with fresh water. Sand, stuck between the sheets, when compressed, can leave scratches on the surface of the plastic, which eventually turn into a network of small cracks.
If persistent contaminations appear on the surface (oil, gasoline, fish mucus), use soft detergents without aggressive solvents. acetone, petrol Or chlorine-containing products can change the structure of plastic, making it matte or sticky, and in the worst case, dissolve the top layer.
To restore slip and protect against UV, you can treat plastic floors once a season with car-made plastic polymers, creating a thin protective film that repels dirt and water.
When stored in winter, plastic is better kept in a straightened state, although it is less susceptible to deformation than plywood. If the boat is stored in assembled form, try to periodically change the position of the cargo inside to avoid residual deformation on the floor in places of prolonged pressure. Storage at temperatures below -10 ° C requires special care when folding - the plastic becomes rigid and can crack on the bend.
Tuning: improving the functionality of the bottom
Once you have a solid plastic bottom, many owners don't stop there and start tuning, and one of the most useful improvements is the installation of guides for cans (seats), and the plastic makes it easy to mount aluminum profiles that can be moved around, locking banks in the right position, which allows you to change the landing depending on fishing conditions or the number of passengers.
Another popular element is the integration of sonar fasteners, fishing rod holders, or even a small table, where you can easily insert mounting pads into a plastic sheet that will be level with the surface without interfering with movement, and to do this, a hole is milled or cut in the plastic, where a mounting element with a burtic is pasted or inserted.
And safety is also important. You can put a slip-resistant coating on smooth plastic, similar to what is used on boat decks, and it can be special abrasively sprayed self-adhesive tapes or EVA mats, which is especially true for boats that are used in rainy weather or for hunting, where there may be water and dirt on the floor.
The plastic bottom is the perfect platform for modernization, its strength allows heavy equipment to be installed, and its chemical resistance ensures that the mounts do not rust after the season.
Can I use a regular sheet polypropylene from a construction store?
Technically, you can, but you have to be careful with the brand. Building polypropylene (often used for formwork) may not have UV stabilizers. When exposed to the sun, it will quickly lose strength and start to crumble. Look for sheets labeled "for outdoor use" or specialized shipbuilding plastics.
How much heavier will the boat become after the plastic flooring is installed?
Weight gain depends on sheet thickness and bottom area. On average, replacing the inflatable floor with an 8 mm plastic sheet will add 5 to 10 kg to the total weight of the tackle, which has a slight effect on motor speed, but can be noticeable when carrying a boat to the water in a disassembled form.
How to cut plastic to fit into the shape of a boat?
It is best to use an electrojigsaw with a metal file (with a small tooth) or a Bulgarian with a wood/plastic disk (at minimum speeds, so as not to melt the edges). For direct cuts, a knife with a replaceable blade will fit, if the plastic is not too thick (up to 4-5 mm).
Why is the floor creaking, even if it is new?
Screeching is caused by friction of dissimilar materials (plastic aluminum) or by the ingress of sand between layers, and it can also be caused by insufficient rigidity of the structure when the sheets are playing on the wave, the solution is the use of lubricants (silicon), gaskets and the elimination of backlashes in the mounts.