Legendary OBE 1 The D16T's robust duraluminium hull, which has been tested for decades, often requires attention due to natural wear, corrosion or mechanical damage, and owners face the need to seal a leak, repaint or reinforce a transom, and the quality of these works directly depends on the safety of the water.
Recovery process aluminum-boat It's a very different experience from fibreglass or PVC, and it requires specific metallurgy skills, argon welding skills, and an understanding of the chemical reactions that occur when metal comes in contact with water, and if you don't fit the right sealant or if you break the welding technology, it can be catastrophic in the first season.
In this article, we will discuss in detail the stages of diagnosis, methods of eliminating cracks and seams, as well as modern methods of protecting the hull. You will learn how to prolong the life of your vessel and whether the game is worth a candle if you get the boat in poor condition.
Diagnosis of the condition of the body and identification of defects
The first step in any recovery is thorough defectThe boat needs to be turned over, cleaned of dirt, mud and old paint. Often, deep corrosion ulcers or microcracks are hidden under the enamel layer, which are not visible on surface inspection, and special attention should be paid to the zygomatic joints and the area around the transom, where the metal stresses are maximum.
To detect microcracks, experienced craftsmen use kerosene testing or special penetrating compounds, and if you apply kerosene to the seam after cleaning and degreasing, and powder it with chalk on the back side, after a while, you will see greasy spots indicating through defects, which makes it possible to avoid missing any problem area before starting the main work.
The metal thickness assessment is critical, and using an ultrasonic thickness meter will help you determine whether you should repair a particular sheet or replace it more easily, and if corrosion has eaten more than 30-40% of the thickness of the sheet, local curing of the pentacles will not have a long-term effect, and it will take a long time to do so. patterning new element.
⚠️ Warning: Never ignore the bloating of paint on the sides. There is almost always a hotbed of active corrosion under the bubble, which will quickly turn into a through hole.
Visual inspection should be done in good light, preferably using a magnifying glass. Cracks in duraluminium often have a direction along the rolled fibers or along the lines of welds. It is important to determine the nature of the damage: it is a fatigue crack from vibration or the result of impact on an underwater obstacle.
Duraluminum welding technology: argon and choice of materials
Basic material of the case Obi. Duraluminum D16T, which is notoriously hard to weld because of its tendency to crack when heated, requires argono-arc welding (TIG) with a non-melting tungsten electrode to be repaired properly, and a conventional electric welding or semi-automatic is not suitable because it burns metal and creates fragile connections.
The key is to choose the filler material. The D16T alloy is most commonly used with wire. AMG6 or AMG5The use of improper wire, such as pure aluminum or silumin, will cause the seam to simply crumble under load after a short time.
- 🔥 Before welding, be sure to clean the edges of the metal to shine and degrease with acetone - the oxide film prevents the formation of a quality seam.
- 💨 The argon supply must be stable, without pulsations, to protect the welding bath from oxidation by atmospheric air.
- ⚡ Welding should be carried out in short seams (arms) in a staggered manner to avoid warping of a thin sheet from overheating.
If you don't have experience welding aluminum, you should leave that part of the job to the professionals. The overheated metal loses its strength (there's a vacation), and the boat can burst on the wave. It's important to keep the temperature in place and not to hold the burner in one place for too long.
Use graphite or copper linings under the seam when welding a thin bottom - this will help to avoid burns and ensure uniform formation of the roller on the reverse side.
Seam sealing and leak removal without welding
There are modern chemicals available to fix small leaks, fistulas or rivet joints, but it's important to understand that sealant is a temporary or auxiliary solution, not a substitute for metal in case of serious damage.
There are many polyurethane and thiocol sealants on the market, such as: Sikaflex, 3M 5200 They have excellent adg-esia to aluminum and remain elastic after drying, which allows you to compensate for the temperature expansion of the case, before applying the surface must be perfectly dry and rough.
| Type of sealant | Basis | Time of complete polymerization | Application |
|---|---|---|---|
| Sikaflex-290i | Polyurethane | 24-48 hours | Structures welding, seam sealing |
| 3M 5200 | Polyurethane | 5-7 days | Reliable sealing of the underwater part |
| Tixol-10-18 | Tiokol | 24 hours. | Filling cracks, fuel tanks |
| Aluminum paste | Epoxy + Al-powder | 12 hours. | Repair of chips and sinks |
When you seal a crack, you drill the ends to relieve the stress of the metal, then you sharpen the groove ("break" the seam) and fill it with sealants. To enhance the effect, you can put a glass cloth on top of it that is soaked in epoxy, and this will create a kind of bandage that will take over some of the load.
⚠️ Warning: Don't use acid silicone sealants (the ones that smell like vinegar) to repair boats! the acid will cause instant corrosion of aluminum and only leaks more.
Recovery and reinforcement of the transone
The Tran is the most loaded part of the body OBE 1It's a machine that takes on the weight of the motor and the pulling forces. Over time, the metal gets tired, there are cracks around the fasteners, and in the worst case, the transom just breaks off. Repairing this area requires a comprehensive approach and often involves installing amplifiers.
If the holes under the bolts of the engine mounting are broken or cracks have gone around them, you can not cook "lively"; you need to cut out the damaged area, insert a repair insert and properly boil it around the perimeter. reinforcement from the same duraluminium from the inside and the outside.
- 🔩 Use only high-strength bolts (Class 8.8 and above) with wide washers to distribute the load.
- 🛡️ The reinforcing scarves shall be welded or glued with a fit on the intact metal of at least 50 mm.
- 📏 When installing a new transom, strictly observe the angle of kilvaternost to avoid burying the nose of the boat on planing.
☑️ Translation check
The wooden transom skin, if designed or made by previous owners, also requires revision. Rotten wood for an outboard motor is a way to quickly destroy the metal base due to constant contact with moisture and vibration. It is better to replace the tree with moisture-resistant plywood or completely abandon it in favor of a properly made metal hazel.
Anti-corrosion protection and painting
The final stage of the repair is to create a reliable barrier between the aggressive aquatic environment and the metal. Duraluminum itself is protected by an oxide film, but in places of welding and mechanical damage, this protection is broken.
The process begins with a complete cleansing of the body to the metal, the old paint is removed with a sandblast, a grinder or a chemical wash, the surface must be matte and rough for better soil adhesion, all irregularities, dents and welding seams are leveled with a car putty with aluminum powder.
Soiling is the most important step. It's aluminium that's used for special purposes. epoxy or soils with zinc (although zinc should be careful because of the risk of electrochemical corrosion, it is better to use two-component epoxy compounds).
Do I need to lay inside the boat?
Inside the boat also forms condensation, especially if it is stored under an awning or in a garage. Put the inner sides and bottom must be sure to prevent the appearance of "white" corrosion and blown stains.
Finishing is chosen based on budget and operating conditions: polyurethane enamel (e.g., polyurethane enamel) Interlux, Alexol) are expensive, but they provide a coating that is resistant to shock and ultraviolet. Alkyd enamel is cheaper, but require more frequent renewal. It is better to apply paint with a spray gun to obtain a smooth surface without leaks.
Cost of repair and feasibility of restoration
Before you jump into the pool with your head, you have to look at the economics. Obi 1. you can do it yourself and cost materials like welding, paint, soil, consumables. If you hire specialists, the amount can grow 3-4 times, approaching the cost of a good used boat in normal condition.
But if the hull is intact, and the problem is only seams and painting, it makes sense to restore it. You get a boat that's 100% sure, you know every bolt and seam. New boats of the same size made of aluminum now cost space money, and it's hard to find a quality counterpart.
If the bottom has turned into a sieve and the bulkheads have rotted, it's easier to find another body, and sometimes it's more profitable to buy a "killed" Ob with a whole bottom but a bad view, and move equipment on it than to resuscitate a corpse.
The repair of the Ob 1 is justified if the frame and main sheets of skin have retained geometry and thickness, and replacing more than 40% of the metal area makes the repair economically inefficient.
Can I seal a hole in the boat Ob with epoxy?
Temporarily, yes, if you're properly prepared (clean, degrease, cut), but on a permanent basis, especially on the bottom, this patch won't last long because of the body deformation as it moves along the wave, which is an emergency option until it's fully repaired.
What kind of solder to use for soldering aluminum?
Duraluminium soldering (D16T) is not suitable for conventional tin lead soldering, requires special high-temperature solderings based on zinc or silumin (e.g. 34A), as well as aggressive fluxes, soldering is less reliable than argon welding, and is suitable only for small defects.
How often should I change the anodic protection on the boat?
Protector treads (magnesium or zinc) are tested every season, and if they have collapsed by more than 50-60%, they need to be replaced, and their task is to collapse themselves, saving the boat hull from galvanic corrosion.