Many owners of Soviet aluminum boats face the problem of stability, especially when installing powerful outboard motors. Kazanka-M or Kazan 5 They were originally designed for low-power engines, so turning can be critical, and adding extra side boules is the most effective way to fix the situation without completely replacing the vessel.
This upgrade not only improves stability, but also increases the useful area of the cockpit, as well as improves the performance of the turbulent, but the process of welding new elements requires strict adherence to aluminum welding technology, since a violation of temperature regimes can lead to the release of metal and loss of strength of the main body.
In this article, we will discuss in detail all the stages of creating boules, from calculating buoyancy to the final painting. Security In water, it depends on the quality of the work performed, so you should not ignore the recommendations of experienced boat mechanics. You will learn what materials are best to use and how to avoid typical errors in welding duraluminium.
The feasibility of installing boules on Kazanka
The main reason fishermen and speed-drivers are taking serious tuning is because they're shifting their center of gravity, and when you put a modern 30-horsepower engine on the trunk of an old boat, the stern starts to scoop, and getting into a turn at speed becomes a dangerous maneuver, and the buoys act as extra floats that increase the width of the lower unit and the moment of resistance to roll.
In addition, additional volumes on the sides allow load-bear This is especially true for those who are taking heavy equipment, tents or several passengers on a hike, and the aluminum sheets that form the boulay add little weight to the structure, but they give a significant increase in displacement.
⚠️ Before starting work, be sure to check the condition of the base metal of the case in the areas of the proposed weld. The presence of cracks or severe corrosion requires preliminary repairs, otherwise the new design will not save the situation.
And it's also aesthetically pleasing, because well-designed boules that replicate the zygomatic contours make the silhouette of the boat more aggressive and modern. Kazan use this opportunity to completely repaint the boat in camouflage or bright monochromatic color, hiding the traces of time.
Calculation of buoyancy and geometry of the structure
Before cutting metal, engineering calculations must be performed: Too narrow boules will not give the desired effect, and too wide will turn the boat into a clumsy barge, increasing water resistance and fuel consumption. The optimal width of the additional board is usually 150 to 250 mm in the widest part.
The Archimedes formula is used to calculate that 1 liter of displaced water is equal to 1 kg of held cargo. However, you must leave a buoyancy margin of at least 30-40% in case of water entering the boules or heavy loading. The length of the boules usually corresponds to the length of the straight side, without reaching the nozzle and the transom by 10-15 cm.
It's important to calculate the angle of keeliness of the bottom of the boules correctly, and it should move smoothly into the angle of keeliness of the main hull, so that there are no hard blows to the water during the course of the wave, and if you make the transition too sharp, the boat will go goat or burrow its nose.
Selection of materials and preparation of tools
For the manufacture of boules, aviation aluminum is most often used. AMG5 or AMG6These alloys are highly corrosive and weldable, and the thickness of the boulder sheet is usually 2-3 mm, which ensures sufficient rigidity without excessive weighting, and the use of thinner metal is unacceptable because of the risk of breakdown.
For power set inside the boules (ribs and frames), profile pipes or strips of the same alloy are used. The anchoring of boules to the main body is carried out through welded corners or directly, if the thickness of the main side (at least 2 mm) permits. Welding It must be produced only in argon medium by a semi-automatic or manual method.
Use wire of the same brand as the base metal (e.g. Sv-AMg6 for AMG5) to avoid galvanic corrosion in the seams.
In addition to metal, you will need a quality degreasing, acetone to remove oxide film before welding, high-purity argon and tungsten electrodes (if cooked by hand).
Technology of manufacture and welding of boules
The process begins with cutting sheet metal into pre-made patterns of cardboard or plywood. The pattern must exactly repeat the bending of your cheekbones. KazanAfter cutting, the parts are assembled into a single structure (box) on the choppers, and cross bulkheads are installed inside every 30-40 cm to prevent collapse when hitting a wave.
The next step is to prepare the main body, and the welding site is cleaned to shine with a metal brush (use the aluminum brush only, without any trace of steel), then fit the finished boules, they must fit tightly to the side along the entire length, and gaps of more than 1-2 mm are unacceptable, because they are difficult to boil properly.
☑️ Boolean welding stages
Cooking should be short seams (by 2-3 cm) spread out to avoid overheating of the metal and its warping. A long continuous seam can lead the thin side of the boat. Pay special attention to the bow and aft ends of the boules - there the concentration of stresses is maximum. After cooling, the seams are cleaned with a petal circle.
Comparison of specifications before and after tuning
To understand the effectiveness of modernization, consider a comparison table of parameters of a standard boat and a boat with installed boules. Kazan and the size of the boules.
| Parameter | Standard Kazanka | Kazanka with boules | Change of change |
|---|---|---|---|
| Breadth on cheekbones | 1200 mm | 1500-1600 mm | +25-30% |
| Stability (full roll) | High risk | Stable. | Significant improvement |
| Displacement (useful) | 400 kg | 550-600 kg | +150 kg |
| Weight of an empty boat | 140 kg | 155-160 kg | +15-20 kg |
As you can see from the table, the weight gain is small, but the safety and comfort gains are huge, and the boat becomes less sensitive to the movement of passengers inside the cockpit, which is especially important for fishing when you need to stand up full-length or make a sharp jump when catching large fish.
But remember that the high sides with boulders react more strongly to the side wind, which can make it difficult to drive at low speeds, and the width of the ladder increases, which should be considered when transporting a boat on a trailer or storing in a garage.
Finishing and painting
After welding and seam cleaning, the surface must be prepared for painting. Aluminum requires special preparation because the usual soils are poorly maintained. It is recommended to use etching soils (phosphate) or special adhesive primers for non-ferrous metals.
Two-component polyurethane enamels or epoxy compounds are best suited for painting, and they create a strong, chemically resistant film that is not afraid of gasoline, oil and ultraviolet light, and it is better to apply the paint with a pneumatic spray gun in 2-3 layers with intermediate drying.
The Secret to Long-Term Painting
Before applying the finish enamel, be sure to degrease the surface with acetone or a special degreasing agent immediately after drying the soil.
The inside of the boules, if they are sealed, it is also desirable to treat with anticory, at least a simple bitumen varnish, in case of microcracks. If the boules are open (not sealed), then painting the internal cavities is not required, but you need to provide drainage holes at the bottom point for draining water.
Typical errors in self-tuning
One of the most common mistakes is saving on the thickness of the metal, and in order to save money, the craftsmen take a sheet of 1.5 mm, which, when hit by a wave or a log, simply bursts on the weld. Strength The design should be redundant, especially given that aluminum is prone to the accumulation of fatigue cracks.
The second mistake is wrong geometry: the boules should not go below the main line of the keel. If the bottom of the boules is below the keel, then when you go to the planing or when you moor, you will be screeching with the boules, which will lead to their rapid destruction. The bottom line of the boules should be an extension of the cheekbones line or slightly higher.
⚠️ Warning: Never use steel wire or steel electrodes to weld aluminum, guaranteed to cause rapid seam breakdown due to electrochemical corrosion in salt or even fresh water.
Also, the reinforcement of the transom plate is often overlooked, and the installation of the boules changes the fluid dynamics, and the load on the transom may increase, check the status of the transom riffles on the transom, and if necessary, add additional scarves from inside the boat.
Outcome recommendations and security
tuning Kazan With boules, it's a time-tested way to give an old boat a second life, and well-designed onboard elements make the boat versatile, both for a quiet fishing with a sonar and for an active water-motor rest, the main thing is to take your time and perform each stage of work efficiently.
Remember that any interference with the design of the swimmer requires responsibility. Once completed, be sure to conduct sea trials in shallow water in life jackets. Check the boat for leaks, circulation stability and wave behavior.
Highly executed boula from AMG5 turn unstable Kazanka into a safe family boat, allowing you to confidently use engines with a capacity of up to 40 hp.
Regularly inspect the welding sites of the boules to the hull. Even small cracks in the heat zone require immediate repair. Careful care and timely maintenance will ensure your boat long and safe operation for many years to come.
Do I need to register a boat with boules in the GIMS again?
Yes, if the change in design (the installation of boules) has led to a change in the basic specifications of the vessel, such as length, width or carrying capacity, it is theoretically necessary to make changes in the documents. In practice, if the boules do not change the dimensions dramatically and do not remove the boat from the category of small craft, owners often leave everything as it is. However, when undergoing a technical examination, the inspector may ask questions if the width of the vessel in the documents and in reality will be very different.
What welding current to set for AMG5 with a thickness of 3 mm?
For manual argono-arc welding (TIG) aluminum with a thickness of 3 mm, the optimal current is 90-110 Amps. However, the exact settings depend on the diameter of the tungsten electrode (usually 2.0-2.4 mm) and the flow rate of argon. It is best to test boiling on the scraps of the same metal before starting the main work.
Can you make the boula removable?
Theoretically, you can use bolts through welded corners, but this creates additional problems: the need to seal the holes, the risk of weakening the fastener from vibration, and the difficulty of providing a rigid connection. Welded boules are more reliable and durable, because they eliminate the points of concentration of stress around the bolts.
How much does one side of a bull weigh?
The weight of one boulder is about 2.5 meters long and 20 cm wide from a sheet of 2 mm will be approximately 6-7 kg. Together with the ribs and scarves, the weight of one side can reach 8-9 kg. Thus, the total weight of tuning (two sides) will add to the weight of the boat about 15-18 kg, which is insignificant for the total carrying capacity.