The tonbox on the boat is not just a tribute to aesthetics, but a necessary functional unit for any owner of a small vessel, whether it is PVC or light aluminum. This box, mounted in the nose or on the transom, solves several critical tasks at once: it protects the engine from shocks during shallow water, serves as a reliable seat for a rower and hides valuable property, fuel or tools from prying eyes. composites They have minimal weight and absolute resistance to aggressive aquatic environment.
Many anglers underestimate the importance of proper installation, relying on the case, but a well-designed tonbox significantly improves the safety of the vessel. It prevents the bow from being overwhelmed by a wave, acting as an additional splasher, which is especially important when driving against the wind. seat-box allows you to comfortably sit on floorboard, without experiencing discomfort from hard floor elements or inflatable tubes in hot weather.
Creating or acquiring such an element requires an understanding of the materials and principles of attachment, since the boat is subjected to constant dynamic loads. fiberglass Before the seams are sealed, so that your boat is not only more beautiful, but also more functional, and a properly selected tonbox will be the center of your boat's ergonomics.
Design features and purpose of tonbox
The tonbox is a hollow, streamlined box that is mounted in the bow of the boat, often when it is on board, and its main purpose is to protect the outboard motor when it is reversing or in shallow water, when the screw can touch the bottom. tonbox It takes the hit, keeping the integrity of the lower unit and the propeller intact, and this is especially important for PVC boat owners, where the risk of a balloon piercing the engine is much higher.
In addition to the protective function, the tonbox is a great place to store. fuel-tankAnchor gear, spare parts or personal belongings, protecting them from splashes and direct sunlight. Many models are equipped with soft overlays, turning the lid into a comfortable seat, saving space in the cockpit and avoiding the need to bring additional folding chairs.
⚠️ Note: When designing a tonbox, keep in mind that its volume should not be completely sealed without air valves unless it is used as a buoyancy unit.
It is also important to note the role of tonbox in improving driving performance: streamlined sides of the box contribute to better separation of the flow of water, which reduces resistance and can slightly increase speed or reduce fuel consumption. material allow you to create structures of complex geometry that perfectly repeat the curves of cylinders or the hull of the boat, without disturbing the hydrodynamics.
Selection of materials: fiberglass, aluminum or plywood
The choice of material for the manufacture of tonbox is a fundamental step in determining the durability and weight of the product. fiberglass This material is highly tensile, does not rot, does not rust and is easily repaired in case of damage, and the plastic tonbox can be made in any shape, allowing it to fit perfectly into the geometry of a particular boat, whether it is a boat or not. Kazanka squishy naughty.
Aluminum is also popular, especially among metal boat owners; lighter than steel but heavier than plastic, and requires high-quality corrosion treatment of welds. Aluminum tonboxes are often made angular, because the complex molding of this metal in the home is difficult, but their strength and resistance to impacts on stones or logs make them an excellent choice for harsh use.
Plywood is the most budget-friendly, but also the most time-consuming option to use on water, and you need top-grade marine plywood that needs to be thoroughly soaked in epoxy resins and stained, even with good processing. wood It gets moisture over time, which increases the weight of the boat, and plywood tonboxes are only advisable if you don't have access to composite technology.
Secrets of working with resin
When working with polyester resins, it is important to observe the temperature regime. If the room is colder than +18 ° C, the resin may not stand up (do not polymerize) even with the catalyst. In such cases, experienced craftsmen use heat guns or add special cobalt accelerators, but this requires precise dosing, otherwise the material will become brittle.
Comparative table of specifications of materials will help to make the final choice:
| Materials | Weight (average) | Difficulty of manufacture | Term of service | Cost |
|---|---|---|---|---|
| Fiberglass | Low. | High. | 20+ years | Medium |
| aluminum | Medium. | Medium | 15-20 years | High. |
| Sea plywood | Highly | Low. | 5-7 years | Low. |
| Polyethylene (PE) | Low. | Impossible (casting) | 20+ years | High (buy) |
Design and removal of dimensions
Before you start purchasing materials, you have to create a detailed design, and design starts with taking the exact dimensions from your boat, measuring the width of the cockpit at the installation site, the height of the sides and the distance to the paiola. dimensions Not only the boat itself, but also the items that will be stored inside (e.g., the height of the fuel tank).
When creating a sketch, consider ergonomics. The height of the seat should be comfortable for rowing or fishing, usually 35-45 cm from the level of the pyeol. If the tonbox is installed on a transom, its shape should allow you to conveniently position the legs and not interfere with the operation of the tiller or remotely located. gaskle.
Use cardboard patterns before you unveil the main material, cut the life-size outlines of the future tonbox from the packaging cardboard, paste them with tape and try them on the boat, which will allow you to see errors in geometry and avoid spoiling expensive fiberglass or metal.
Remember to provide technological holes. drainage It's also a good idea to have hatches or a removable lid to access the contents without removing the entire drawer, and it's best to have all the corners in the drawing rounded, which is not only aesthetically pleasing, but also to increase the strength of the structure, reducing stress concentration.
Technology of production of fiberglass
Making a tonbox of fiberglass yourself is a time-consuming process, but rewarding. You'll need a matrix (shape) that can be made from foam or plywood, fiberglass (better to use a structural one, such as a T-11 or T-13) and a binder (polyester or epoxy resin). formworkIt repeats the desired shape of the box.
A separation layer (wax or PVA) is applied to the prepared surface, after which the layers of resin-soaked glass tissue are laid down. It is important to carefully roll each layer with a roller to drive out the air bubbles, which are the main cause of stratification and cracking. To strengthen the structure, additional strips are laid at the attachment sites and on the ribs of rigidity. reinforcement.
⚠️ Attention: Polyester resins and fiberglass are only used in a well-ventilated environment or outdoors, styrene vapors are toxic, and fiberglass dust causes severe skin and airway irritation, and use a respirator and gloves!
Once the resin is polymerized, the product is removed from the matrix, grinded and painted. For boat elements, two-component polyurethane paints are ideal, which create a durable, glossy coating that is resistant to ultraviolet and salt water. The interior is also desirable to cover with gelcoat or waterproofing paint.
☑️ Lamination steps
Installation and anchorage to the boat
The attachment of the tonbox to the boat is a critical moment on which safety depends. bracket Stainless steel or aluminum that covers the cylinders without clamping them. Between the metal elements and PVC must be a soft pad (for example, microporous rubber) to avoid friction.
On metal boats, the tonbox is often welded or screwed with bolts through rubber shock absorbers. shock absorbers The rigid bonding of the two metal structures will cause the welds or the tonbox itself to quickly collapse due to vibration when the engine is running.
If you use a transom tonbox, make sure it doesn't shift the boat's center of gravity too far back, which can lead to the transmolant being buried in water and reduced planing efficiency. When installing a nose box, it's important that it doesn't interfere with viewing and handling.
Care and maintenance in season
Proper care of the tonbox will prolong its life and preserve its appearance. After every fishing, especially in salt water, the box must be rinsed with fresh water. The salt, when dried, forms crystals that can scratch the paint coating and accelerate the corrosion of metal attachments.
Regularly check the condition of the fasteners and tightness of the seams. If you find microcracks in the fiberglass, they must be fixed immediately, otherwise the water, freezing in winter, will expand the damage. ventilation internal volume.
Regular washing and checking of fasteners is a guarantee that the tonbox will not turn into a source of problems in the middle of the reservoir.
Internal surfaces should be periodically treated with anti-corrosion compounds, if metal is stored there, it is also not recommended to store fuel in a tonbox in leaky canisters for a long time, since gasoline vapors can accumulate, creating an explosive situation.
Frequently Asked Questions (FAQ)
Can I use tonbox as a buoyancy block?
Theoretically, yes, if it's sealed and secured so it won't come off in a flip, but it requires special calculations of the volume and strength of the mounts. Standard tonboxes for storage are not designed to handle the loads that arise when an inverted boat with a crew surfaces.
What thickness of fiberglass is better to choose for a beginner?
For beginners, the T-11 or T-13 fiberglass (about 0.2-0.25 mm thick) is optimal, it is easier to soak in resin and it is easier to drive out bubbles. The thicker fabrics (T-23 and above) require skill, since the resin may not soak through them, leaving dry stains.
Do I need to paint the tonbox from the inside?
The paint or gelcoat inside protects the fiberglass from moisture (although fiberglass itself is moisture resistant, unprotected ends and microcracks can draw water) and makes cleaning the box easier, and the light color inside will make it easier to find small objects.
How much does fiberglass tonbox dry?
The primary polymerization time is about 24 hours at +20°C. However, complete polymerization and strength gain occur within 7-10 days. Before this period, loading the product or drilling holes in it is not recommended.