How to Buy a Bottom for a PVC Boat: A Complete Guide to Choosing

Operation of inflatable boats is often associated with wear of rigid elements, and the owners sooner or later face the question: where and how to buy the bottom for the PVC boat. load-bearingThis is a hull that provides stiffness, protection from sharp objects at the bottom of the reservoir and stability when people are on board, and the safety of the crew and the durability of the cylinder directly depend on the quality of this element.

The market offers a variety of solutions, from factory originals to handicrafts, which creates confusion among the buyer: improperly selected plywood can swell after the first season, and poor-quality aluminum can deform under load. In this article, we will analyze all the nuances of material selection, consider the features of the material. plywood and metallic We will also recommend the replacement or manufacture.

You have to make an informed decision based on the operating conditions of your vessel: Will you go out to sea with a powerful engine or prefer quiet fishing on a lake with oars? The answers to these questions will determine what type of bottom you need.

The main types of bottoms for inflatable boats

The first thing to decide before buying a bottom for a PVC boat is the type of design. The modern industry offers several basic options, each with its own advantages and disadvantages. floor-floor (Air Deck), slug-hard Hard Bottom and combined solutions, depending on the class of the boat and the requirements for its performance.

Inflatable floors are valued for their light weight and compactness when assembled, and are ideal for mobile fishermen who often travel between bodies of water on public transport or carry a boat for long distances, but they do not provide the stiffness required for glides with a powerful motor. plywood or aluminum Slange create a hard surface, allowing you to confidently stand on your feet and install powerful power units.

Hard bottoms are also divided into flat bottoms (Flat Bottom) and keel bottoms. Flat bottoms are easier to produce and cheaper, but they are worse at dissecting waves. quillson It's a great way to improve seaworthiness and stability, and if you're planning to use it on the wave, you're going to have a boat with a hard bottom on the keel.

• 🚤 Air Deck: Light weight, excellent comfort, but low stiffness and the risk of puncture.
• 🪵 Plywood flooring: classic solution, high rigidity, maintainability, but high weight and susceptibility to moisture.
• ⚙️ Aluminum leaf: maximum strength, resistance to rotting, but high price and risk of corrosion in salt water.

⚠️ Warning: Never use conventional building plywood without special treatment to replace the bottom in a PVC boat. moisture will quickly penetrate the pores of the tree, which will lead to the stratification and rotting of the material within one season.

It is also worth mentioning the so-called RIB-ah Rigid Inflatable Boats, where the bottom is made of fiberglass or aluminum as a unit with cylinders, and you can't replace the bottom in this design, because it's a matter of overhauling the housing, not buying an expendable element, and we're talking about collapsible models where the floor is a removable element.

Plywood bottom: material selection and processing

If you decide to buy a plywood PVC boat bottom, the key is the brand of the material. plywoodIt is made from hardwood veneer (usually birch) using water-resistant phenolformaldehyde glue, labeled as FC or, better yet for extreme conditions, FF, although less environmentally friendly, but more resistant to aggressive environments.

The thickness of the sheet also plays a critical role. For small boats (up to 3 meters) 9 mm thick is sufficient. For larger models, especially those designed for operation with a motor of 5 hp, it is recommended to use plywood thickness. 12 mm Insufficient thickness will lead to the fact that under the weight of passengers and the engine, the bottom will begin to bend (“play”), which causes discomfort and can damage the docking places with the balloon.

You have to pay special attention to the ends of the plywood sheet, and that's where the moisture gets in the material the fastest, and when you buy a finished product or make it yourself, you have to make sure that the ends are carefully cut. laminated They're painted with a few layers of epoxy, and some manufacturers use perimeter aluminum edging, which greatly extends the life of the cell.

The weight of the plywood kit is its main drawback: a set of sleighs for a boat 3.5-4 meters long can weigh from 15 to 25 kg. This significantly increases the total weight of the equipment, which is important to consider if you plan to often carry the boat alone. However, the rigidity and feeling of hard soil under your feet completely compensate for this disadvantage for many water engines.

Aluminum slugs: pros, cons and features

The alternative to wood is metal, and here the leader is no alternative. aluminumBuying an aluminum bottom for a PVC boat is an investment in durability. Aluminum doesn't rot, absorb water, or change its weight during operation. It's ideal for anyone who keeps the boat assembled in a garage or trailer, because they're not afraid of temperature and humidity.

But aluminum has its enemies. electrochemicalIf you use a boat in salt water, contact with other metals (such as motor lower unit or transom) can cause the material to collapse rapidly. The second disadvantage is noise. Raindrops or waves hitting the metal bottom create significant noise that can interfere with fishing. The third factor is thermal conductivity: it is unpleasant to sit on cold metal, additional insulation with mats is required.

Structurally, aluminum bottoms are often made as profiling sheets (rigidity ribs) or as a set of profiles that are assembled into a single plane; the sheet bottom is heavier but stronger; the set is lighter but may have gaps where sand and silt are clogged, making cleaning more difficult.

Characterization	Plywood (Marine)	Aluminum (AMG)	Plastic (HDPE)
Weight.	Medium/Severe	Medium.	Light.
Moisture resistance	Requires processing	High.	Absolute.
Toughness	High.	Very high.	Medium
Price.	Low/Mediocre	High.	Medium
Repairability	High.	Low.	Low.

When choosing an aluminum variant, it is important to pay attention to the alloy brand. AMG It's a magnesium alloy that's very corrosion-resistant and very durable, and using pure aluminum or soft alloys can deform the bottom for an outboard motor load.

Geometry and compatibility: flat or keel?

The geometry of the bottom is often overlooked when the owner decides to buy a new bottom for the PVC boat. The shape must strictly conform to the design of the balloon. If your boat has an inflatable keel, then the hard bottom must have the appropriate groove or protrusion to install it. The flat bottom in the keel boat just won't fall into place or breaks the hydrodynamics.

Keel bottom It consists of several sections connected to each other, with a central section having a keel profile, which provides stability and allows the boat to keep its course better, especially in lateral winds. quillson - longitudinal stiffness element, which takes on the load from the transom and motor, distributing it along the entire length of the cylinder.

What is a kielson and why is it needed?

The keel is a rigid beam (wooden or aluminum) that runs along the diametrical plane of the boat under the sleigh, prevents the bottom from being deflected by the weight of the engine and passengers, and protects the inflatable keel from damage by sharp objects at the bottom of the reservoir. Without the keelson, operating a boat with a powerful motor at high speeds is dangerous.

Flat bottoms are easier to make and cheaper, and they consist of rectangular or trapezoidal sheets connected by stringers, which are suitable for boats without an inflatable keel or for models where maximum interior space and ease of assembly are the priority, but in the wave, a flat bottom boat will behave less predictably, prowl harder and less plane.

When ordering or buying, it's important to know exactly the model of the boat and the year of manufacture. frigate or hunter The geometry of the bottom can vary from year to year, and the best way to be sure is to take measurements from the old bottom, or to use a factory pattern if it's preserved.

Where to buy: factory products or order from private owners?

The market offers two main ways to solve the problem: to purchase the original bottom from the manufacturer of the boat or order the manufacture from specialized craftsmen. bottom It guarantees perfect compatibility. You get a product that's designed by engineers for your model, with the right angles, can openings and mounts.

But original parts are often expensive and have to wait unless they're in stock, and manufacturers sometimes save on materials using medium-quality plywood, and private craftsmen and small workshops come on to the stage, and they can make the bottom to your individual size, use it. plywood increased strength or make a reinforced version under a heavy motor.

When ordering from private individuals, it is important to require a portfolio of works and reviews. A good master always uses high-quality fittings: stainless bolts, reliable stringer connections. Also, you can often order custom solutions from private individuals, such as the bottom with integrated runduks or a reinforced transom node.

⚠️ Warning: When ordering the bottom "to order" be sure to specify the type of glue used for plywood. the adhesive must be water-based or specialized water resistant. Use of cheap adhesive compounds can lead to the release of toxins and the layering of the veneer.

Pricing varies widely: plywood bottoms can cost between 30% and 60% of the cost of a new boat, depending on the complexity and material. Aluminum variants tend to cost 40-50% more than plywood ones.

Hard bottom installation and maintenance

The proper installation of the bottom is the key to the long service of the boat. The process begins with the layout of the balloon on a flat surface. It is important to make sure that there are no sharp stones or branches under the boat that can damage the material when stretched. First, a transom board is installed (if it is removable), then sections of the bottom are consistently laid, starting with the bow or from the transmolent, depending on the design.

The key point is installation stringer They are inserted into the slots between the plywood sections, and when pumping a boat, the stringers must be tightly pressed against each other, creating a monolithic plane, and if the stringers are too tight, they can be slightly smeared with talc or soap solution, but not by force, so as not to damage the plywood grooves.

Maintenance of the bottom consists of regular inspection and drying. After each fishing, the plywood floor must be wiped dry with rags and let it dry completely before packaging. Keeping the boat assembled with a wet bottom is a sure way to get mold and rot. Aluminum bottoms require periodic cleaning of oxides and checking of attachment sites.

If you notice that the plywood has started to fluff or there are chipped varnishes, immediately start restoration, clean the damaged area with sandpaper, degrease and coat with a new layer of epoxy glue or varnish, timely repair will extend the life of the bottom for several seasons.

Frequently Asked Questions (FAQ)

Can I use regular laminated plywood for the bottom of the boat?

You can only use laminated plywood as a temporary solution, and the laminate only protects the surface, but the ends and any scratches will become the gateway to moisture, and the inside of this plywood will quickly dissipate, and if there is no other way out, the ends should be thoroughly soaked with epoxy and painted.

How to calculate the required thickness of plywood for a boat 3.2 meters?

For a boat with a length of 3.2 meters, designed for operation with an engine up to 5-8 hp, the optimal thickness will be 9-10 mm. If you plan to install a more powerful engine or frequent transportation of heavy loads, it is better to choose 12 mm.

Which is better: a single-section bottom or a set?

The single-section bottom (whole sheet) is extremely rigid and tight, but it is inconvenient to transport and difficult to fit into a narrow cylinder. The dial bottom (of 3-5 sections) is more compact in folded form and easier to assemble, but requires stringers and more complex assembly. For boats longer than 3.5 meters, the dialing bottom is almost uncontested.

How often should I change the bottom of a PVC boat?

If properly operated and stored, a quality plywood floor lasts 5-7 years. Aluminum can last 10 years or more. However, if the boat is often stored in a damp garage or under a condensate awning, the life of the plywood can be reduced to 2-3 years. Regular inspection of the condition of the ends and surface will help determine the need for replacement.