How to collect the bottom of the PVC boat: from inflatable to hard

PVC boat bottom assembly is a process that can dramatically change the performance of your vessel. Many inflatable boat owners will sooner or later face the need to upgrade or repair this critical part of the structure, and it is the condition and type of bottom that determines water stability, plane ability and overall comfort while fishing or cruising.

The question of how to assemble the bottom of a PVC boat often arises when buying a used kit without instructions or if you want to replace the soft inflatable floor with a more rigid structure. Incorrect installation of elements can lead to deformation of cylinders, slowing down the speed or even depressurizing the seams at the most inopportune time. coatboard and load distribution.

In this article, we'll look at different types of bottoms, from simple inflatable to complex stringer-mounted assemblages, and learn what tools you'll need to work with and how to avoid the typical novice mistakes. A properly assembled bottom turns a soft can into a full-fledged speedboat.

Types of bottoms for PVC boats and their features

Before you start assembling, you need to clearly understand what type of bottom you are dealing with. inflatable floor (NDB), hard-bottomed Each type has its own unique build and operation specifications that cannot be ignored.

The low-pressure inflatable floor is a single, sealed chamber that, when pumped, takes a rigid shape. The assembly is minimal: you just need to straighten the folds and plug the pump in. However, such models often require additional reinforcement to go into plane with a powerful motor.

The hard-bed pitted bottom consists of individual aluminum or plywood slabs (sleeves) connected and inserted inside cylinders, a classic scheme that provides excellent rigidity. Stringers in such systems play the role of ribs of stiffness, not allowing the bottom to bend under the weight of passengers and the engine.

• 🛶 NDNDM: Maximum comfort, but less speed and sailing.
• 🔩 Pyola: high speed, excellent handling, but more difficult to assemble.
• ⚖️ Combie: a combination of an inflatable nose cockpit and a rigid aft compartment.

The choice of the type of bottom depends on the operating conditions. For quiet fishing from the shore, the inflatable option will also work, while for long crossings and large waves, a rigid dialing floor is preferable. It is important to consider that the weight of the structure with aluminum slugs will be much higher.

⚠️ Attention: Never attempt to install rigid plywood sleighs in a boat designed exclusively for NDND. This can lead to overstrain of the seams and rupture of cylinders due to the lack of necessary compensators.

Required tools and materials for assembly

You can't build well without the right tools, and even if you're just changing worn-out parts, you're going to need a set of tools, and you don't need to use any tools that can damage the delicate PVC fabric or deform the aluminum profile.

The main element for working with patio floors are stringer Long profiles running along the bottom, which can be made of aluminum or fiberglass, and often require special bolts, nuts and washers to fix them, which must be made of stainless steel brand. AISI 316 or AISI 304.

If it is about repairing or making reinforcements yourself, you will need:

• 🔨 Rubber sleigh fitting without damaging the edges.
• 📏 Roulette and marker for accurate position marking of stringers.
• 🧴 Special glue for PVC (two-component polyurethane) in the case of adhesive amplifiers.
• 🧽 Degreasing agent (acetone or alcohol) for surface preparation.

Pay special attention to the condition of the fasteners. The rust on the stringer bolts is not only an aesthetic problem, but also a risk of damaging the fabric when dismantled. It is better to immediately replace all the fasteners with a new one if the boat was operated in salt water.

A high-quality pump with a pressure gauge may be required to operate the inflatable floor. Pumping or not pumping NDND critically affects the rigidity of the entire structure. Using a car compressor without pressure control often causes seams to rupture in hot weather.

Step by step: Assembly of the pile bottom with stringers

Building a classic hard bottom is a consistent process that requires attention to detail. A mistake in the first sleigh laying phase can cause the rest of the elements to fall into place. Start on a flat, clean surface, away from prickly plants and sharp stones.

The first step is always to arrange the cylinders, spread them so that they lie flat, without strong clatters, then put side sleighs (if the design provides for their separate installation) or central plates. It is important to follow the order indicated in the product passport, since sleighs are often numbered.

After the main plates are laid, it's the stringer line, and these long profiles are cut through special holes or placed in grooves between the sleighs, and they're supposed to tie the entire structure together into a single monolith, and when you install them, you have to make sure that the ends of the stringers are resting on the transom inserts or on the nose pockets.

Puff nuts on stringers should be made evenly. First, get all the nuts by hand, then gradually tighten them with the key, moving from center to edge. Excessive force can lead to bending of the aluminum profile, and a weak puff to the appearance of backlashes and creaks when moving.

• 🔍 Make sure that no edge of the sleigh rests on the seam of the balloon at an acute angle.
• 🔩 Make sure the bolt heads are recessed and do not touch the fabric when inflated.
• 🌊 After assembly, check the flatness of the bottom - there should be no "humps" or "mes".

The final chord is pumping the cylinders. Do this gradually, letting the material stretch. After full pumping, check the tension of the stringers again, because when the pressure in the cylinders changes, the geometry of the bottom can change slightly.

⚠️ Attention: When assembly, never use sharp tools (knives, screwdrivers) to sleeve. One awkward movement can penetrate the cylinder, and the boat will become unusable.

Modernization: installation of plywood reinforcement and keel

Many owners are looking to improve the boat's performance by placing an extra hard bottom on top of the standard NDNDM, which reduces water resistance and makes it more confident to glid, but this upgrade requires accurate weight and balance calculations.

To create reinforcement is usually used moisture-resistant plywood brand FSF The sheets are 9-12 mm thick, and they are painted exactly along the inner contour of the bottom, and it's important to round all the corners and grind the ends so that they don't rub PVC fabric as they move and vibrate.

The key is fixing the gain, which should not be loosely dangled inside, but it should not be rigidly attached to cylinders, and the best option is to use existing pockets for sleighs or create a system of belts that run under the bottom (if the design of the boat allows it). When installing plywood, be sure to leave gaps in 5-10 mm from the sides to compensate for the thermal expansion of the material.

Installing a removable hard keel is another popular upgrade, and the keel is attached to the transom and stretches along the bottom, creating a sharp cheekbones, which greatly improves course stability, and fastening is done through special eyelets on the transom and cylinder.

Repair and replacement of the elements of the bottom

Over time, the elements of the bottom wear out. Aluminum stringers can bend, plywood sleigh can be stripped of moisture, and the inflatable floor loses its tightness. Timely repairs extend the life of the boat for many years.

If the slate has been layered, you can try to repair it by soaking the ends with epoxy resin and pulling rods together. However, for the central part of the boat carrying the main loads, it is better to make a new part from the same plywood of the FSF. Be sure to treat the new slate with varnish or special impregnation to protect against water.

Repairing the inflatable floor requires cleanliness and dryness. The puncture site is cleaned, degreased and sealed with a patch of the same PVC material. The use of PVC glue is critically important - the usual "moments" or epoxy are poorly maintained and the elasticity of the seam is disturbed.

• 🔧 The bent stringer can be straightened, putting on a flat surface and loading with a load.
• 🧵 Gusts of fabric along the seams require professional gluing in the workshop.
• 💧 Always dry the boat before long storage to avoid mold on the bottom.

When you replace the stringer fasteners, it often turns out that the holes in the tissue are stretched, in which case you have to use washers of increased diameter or put additional reinforcing pens around the hole.

Frequent errors in assembly and installation

Inexperienced water engines often step on the same rake, and avoiding them will help to know the typical scenarios of improper operation, the first and most common mistake is assembling a boat on dirty sand or asphalt, small pebbles caught between the sleigh and the cylinder, work like an abrasive and quickly wipe the fabric.

The second mistake is ignoring the assembly sequence, trying to force the last slate when the stringer is not yet installed, deforms the entire geometry, the boat becomes "bubbly", holds its course poorly and wears out faster.

The third problem is that we use the wrong materials for repair, and trying to glue a PVC boat with inflatable boat glue is doomed to failure, because these materials have different chemical structures and do not bond to each other at the molecular level.

⚠️ Attention: Never leave a assembled boat with hard sleighs installed under direct sunlight for long periods unattended. The air in the cylinders heats up, the pressure rises, and the hard elements can push the fabric from the inside out.

Also worth mentioning is the weight saving error: In an effort to make the boat lighter, some people remove some of the sleigh or stringers, which causes the bottom to walk, the engine gets hydraulic shocks, and passengers to feel uncomfortable from constant vibration.

Boat maintenance and storage

The proper maintenance of the bottom is the key to the longevity of your boat. After each trip to the water, especially in salt water or muddy rivers, the boat must be washed. Sand and silt, stuck in the folds of the bottom, when drying, turn into an abrasive paste.

Drying is critical. Slanks need to be allowed to dry completely before they fold the boat. Wet plywood inside a closed case is the perfect medium for a fungus that will destroy not only the wood but also the fabric of the cylinders. Aluminum stringers are also better wiped with dry rags.

Keep the boat straightened or half-assembled, if space allows. If that's not possible, fold it carefully, trying not to make sharp bends in the docking of rigid elements. The optimal storage temperature is from -10 to +30 degrees.

• 🧼 Use a soft sponge and soap solution to clean the bottom.
• ☀️ Avoid drying in the open sun during peak heat.
• 📦 When storing, put bags of silica gel on the bottom of the boat to absorb moisture.

Check the keel and slingboard amplifiers regularly, and they take the brunt of the mooring and shoreing, and the weak bolts need to be tightened and the cracks removed immediately.