The use of rigid deck inflatables (HBV) offers a wide range of opportunities for the fisherman, turning a regular walk into full-fledged trolling or many hours of fishing with comfort. Flagship or hunterIt often involves only inflatable seats, cans, which quickly tire the back. frame-chair It is not just a whim, but a necessity to maintain health and improve fishing efficiency.
The main difficulty is that soft sides and flexible floorboard can not serve as a reliable support for heavy construction without the risk of damage. The frame for the chair in the PVC boat with NDNDM must be designed to distribute the load exclusively on rigid elements - transom, stringers or special linings, bypassing puncture-sensitive cylinders. In this article, we will analyze all the nuances of creating and installing such a design, drawing on the experience of professional boaters.
You have to start by deciding what type of mounting you want, because it's what you want to build, and it's what you want to do, and you have a number of proven schemes that have their own advantages, depending on the size of your boat and the style you want to fish, and it's important to understand that there's no one-size-fits-all solution, and what's ideal for a two-seater boat might be redundant or not enough for a larger model.
Selection of material for the frame: aluminum or stainless steel
The first and most important step is to choose the metal from which the frame will be made. The market offers two main options: aluminum profile (most often duraluminium D16T) and stainless steel. Aluminum is much lighter, which is critical for small boats, where every extra kilogram affects speed and handling. aluminum-tube It is easier to process at home, they do not require complex welding equipment - a sufficiently high-quality argon welding machine or even special connecting elements.
Stainless steel, in turn, has excellent strength and durability, but has a significant weight. The design of stainless steel will be characterized by high inertia, which can adversely affect the centering of the boat, especially during sharp maneuvers. However, if you plan to install a massive rotary chair with a large margin of safety for fishing in large waters, this option is eligible for life.
When choosing a profile, you should pay attention to round pipes with a diameter of 20-25 mm or profile pipes 20x20 mm. Round section is preferable from the point of view of aerodynamics and ease of gripping used, if the frame will also be used as a handrail. Profile pipe is easier in docking and welding of angular connections, which can make it easier for a beginner. The surface of the metal should be carefully cleaned and, preferably, anodized or covered with powder paint to protect against salt water and ultraphyet.
⚠️ Attention! When welding aluminum structures in the vicinity of the installation site on the boat, make sure that sparks or drops of hot metal do not get on the PVC fabric. Even one random spark can burn through the cylinder, making the boat unusable.
To ensure the necessary rigidity and safety, the best choice is (wall thickness) at least 2 mm for aluminum and 1.5 mm for stainless steel. The thinner metal can deform under load or when hitting the side during landing.
Design features of frames for boats with NDND
Low-pressure inflatable floor (LDPB) boats have a unique architecture where the rigidity of the structure is ensured not only by inflated cylinders, but also by a system of stringers and transom bulkheads. The frame installation must take this into account. Unlike plywood floorboard boats, where you can rely on sheets of plywood, in NDB, the points of support are exclusively sink-board and, in some cases, longitudinal stringers, if they are made of rigid material and are located close to the sides.
The most common and reliable design is a U-shaped frame that is attached to a transom. The vertical struts of such a frame are lowered down along the transom plate, and the horizontal bar serves as the basis for mounting the chair. This scheme allows you to completely unload the bottom of the boat, transferring the weight of the angler and equipment directly to the transponder, the strongest part of the boat, this is especially true for small and medium-sized boats, where space inside the cockpit is limited.
There are also combined options where the frame has additional support points on the sides or special brackets that cling to the liner cable. However, such solutions require individual fit and can interfere with the movement of the boat. For most users, the best solution is the transom version, which is easily dismantled and does not take up useful space when transported in a folded form.
When designing, consider the dimensions of the chair itself. The standard fishing chair has a seat about 40-45 cm wide, but with armrests, this figure can reach 60 cm. The frame should be wide enough to provide stability, but not so wide as to interfere with rowing or passage to the bow of the boat. The height of the chair back also matters: too high a back can create sailing or interfere with the view if you sit low.
Drawings and calculation of dimensions: assembly instruction
Before cutting metal, you need to create an accurate drawing or at least a detailed sketch with the dimensions. A mistake in the calculations at this stage can lead to the fact that the frame will mow the boat or simply will not stand up. The standard height of the seat above the bottom (or paiola) should be 40-45 cm for a comfortable landing. If you make the seat lower, you will find it difficult to get up, if higher, you will increase the risk of falling when pitching.
To create a frame, you will need the following set of tools and materials:
- 🛠️ Aluminum pipes with a diameter of 25 mm (wall 2 mm) - 4-5 meters linear.
- ⚙️ Flanks or plates for fastening to a transom - 2 pieces (from stainless steel or aluminum 5-6 mm thick).
- 🔩 Fixing elements (bolts, nuts, washers) made of stainless steel - a set of M6 or M8.
- 🎨 Soil and paint on metal or composition for anodizing.
The assembly process begins with the slicing of pipes according to the drawing. Vertical racks are usually 50-60 cm long (depending on the height of the transom and the desired height of the chair), and the horizontal bar is 50-60 cm Welding is better done in the environment of argon, using a filler rod of the same brand as the base metal. This will ensure maximum strength of the seam. After welding, the seam must be cleaned with a petal circle to remove sharp edges and inflows.
☑️ Preparation for frame assembly
The important thing is to make fasteners. To fasten the frame to the transom, special brackets are used that cover the top edge of the transom plate. These brackets must have soft rubber or silicone pads so that PVC does not damage when the bolts are tightened. The distance between the attachment points should correspond to the width of your boat in the transom area.
Methods of fastening the frame to the boat
Safety is not just a matter of comfort, it's a matter of life. There are several basic ways to fix the frame on a NDL boat, and the choice depends on the design of your boat. The most popular method is mounting to the slab, which uses U-shaped braces or special clips that are put on the top edge of the tan and fixed by screws, which allows you to quickly remove and install the frame without having to drill the boat.
The second option is to use regular sledging stands or bolts, if they are located in the right places, and the frame can be attached to them with carbines or studs. This method is less versatile, because it requires the same geometric dimensions, but it is completely safe for the sides. Some anglers practice a combined method, where the frame is based on a transom, and for additional stabilization use of stops in inflatable tubes through special protective platforms.
The third, most difficult, but also the most reliable way is to integrate the frame into the boat structure through the hinge bars, in which case the frame is made of response parts that are snapped or screwed to elements rigidly bound to the cylinders, but for boats with NDNDT this method is often unacceptable because of the risk of deformation of the bottom when the load is not correct.
| Type of attachment | Difficulty of installation | Reliability | Impact on the boat |
|---|---|---|---|
| On the transom plate. | Low. | High. | Minimum |
| To the leer tubbas | Medium | Medium | Missing. |
| Emphasis on the side (through protection) | High. | Medium | Requires protection. |
| Integrated (jams) | High. | Very high. | Risk of deformation |
In any form of attachment, be sure to use grover washers or a thread lock, as vibration from the motor can gradually weaken the connections. Check the bolt tightening regularly before each step into the water.
Use rubber or silicone pads with a thickness of at least 3-4 mm in the areas of contact of the metal with PVC. This will prevent the rubbing of the fabric and the formation of microcracks when vibrating.
Protection of cylinders and floorboard from damage
Although strong, BND boats are vulnerable to mechanical damage; a metal frame, especially in conditions of constant vibration and water movement, can become a source of problems if not taken care of protection; the main danger comes from the sharp edges of the fasteners and the frame itself, which can rub against cylinders when rolled.
To protect the contact points, use special rubber linings, a car camera or a specialized PVC tape. A good solution is to use a large-diameter shrink tube on the lower parts of the frame struts. It will create a soft but strong barrier between the metal and the fabric of the boat. It is also recommended to paste the sides in the places of possible contact with a protective film or "armored film", which is sold in the shops for tuning boats.
Pay special attention to the contact area of the frame with the floorboard, if the frame has lower supports. Even if the support is on the stringer, vibration can be transmitted to the inflatable sections. Use wide support pens that increase the contact area and reduce the specific pressure on the surface. It is critically important to avoid point pressure of metal at the joints of the NDND sections, as this can lead to depressurization of the seams.
⚠️ Attention! Never put the frame on the eye. Be sure to test the load on the shore: sit in the chair, sway from side to side and check if any part of the frame touches the soft elements of the loaded boat.
Installation of the rotary mechanism and chair
Once the frame is ready and installed, it is the seat itself that is mounted, and for fishing, the most convenient option is to use a rotary mechanism with the ability to lock in different positions, which allows you to quickly turn around to throw or catch the fish without getting up, and the mechanism is attached to the horizontal crossbar of the frame through the intermediate platform.
The seat mounting area should be large enough to be stable. The optimal size is a 20x20 cm square or a 20 cm circle. The mounting is carried out on 4 bolts. Between the mechanism and the platform, and between the platform and the frame, it is desirable to install rubber dampers. They will extinguish the vibration that is transmitted from the motor and water, making the seat more comfortable and prolonging the life of the fasteners.
Choose the chair according to the operating conditions. In hot climates, the best models are those with a mesh back and seat that do not heat up in the sun and dry quickly. In cold water, the ideal seats are those with soft upholstery and high sides. Make sure that the turning mechanism has a reliable hold so that you do not turn your back to the movement at the most inopportune moment.
Secrets of a comfortable landing
For long fishing, choose a seat with backrest adjustment. Even a small angle of 100-110 degrees significantly reduces the load on the lower back compared to a vertical landing of 90 degrees.
Frequently Asked Questions (FAQ)
Can I install a frame on a boat without drilling a transom?
Yes, it's possible. There are clamp-frame models that attach to the top of the transom plate with powerful screw clips that don't require drilling holes or leakage, but they're less reliable than a bolt, and they require regular tightening checks.
What is the maximum weight of a homemade frame?
When using an aluminum pipe with a diameter of 25 mm with 2 mm and high-quality welding, the frame calmly withstands a load of up to 150-180 kg. This is more than enough for any angler along with equipment.
Do I need to remove the frame when transporting the boat in assembled form?
Yes, the frame needs to be dismantled. Even if it seems compact, when folding the boat and packing it into a bag, the rigid elements can damage the fabric or shift, creating dangerous pressure on the seams. The frame is easily disassembled into its components (if designed) or removed entirely.
Does the chair frame affect the stability of the boat?
It does, but it's not that important if the frame is made of lightweight materials and properly mounted, and the center of gravity shifts upwards, which theoretically reduces stability, but in practice, when you're loading the boat and you're sitting in a chair (rather than standing), it's almost invisible, and you're compensated by the ease of handling the gear.
Properly designed and installed frame turns an ordinary inflatable boat into a full-fledged fishing boat, allowing you to fish with the comfort of a professional, without sacrificing the mobility and ease of PVC rafting.