The construction or modernization of an inflatable vessel often requires the installation of a hard bottom, and plywood It's a leader in terms of price and strength, but when it gets into an aggressive aquatic environment, it quickly loses its properties, dissects and rots without proper protection, and boat owners often wonder what composition to choose to forget about the problem of getting wet for years.
Wrongly selected infiltration Not only can the transom not save the transom, but it can also damage the balloon by breaking the adhesive seams or the rubber layer upon contact, and in this material we will go through the chemical and physical properties of the various coatings, as well as the application technology that guarantees them. waterproofing Even in extreme conditions.
Deep. conservation Wood is not just a surface painting process, but a complex process of saturating fibers with protective components, you will learn why cheap varnishes are not suitable for constant contact with water and how to prepare the surface for the perfect result.
Criteria for the choice of protective composition for the boat
When choosing a treatment tool, you need to consider the specifics of operating an inflatable bot, where mechanical stress is combined with constant exposure to moisture. Conventional construction varnishes designed for floors or walls may not withstand cycles of heating in the sun and cooling in the water, which will lead to microcracks. The key parameter here is the elasticity of the dried film, which must work on stretching together with the plywood material.
It is also important to pay attention to adherence The compound is adhesive to wood fibers, because it prevents the coating from peeling off when it hits the bottom. Many drivers ignore the chemical compatibility with PVC, which is a big mistake, because solvent vapors or direct contact of liquid composition can melt the cylinders.
When choosing an impregnation, always read the label for compatibility with polyvinyl chloride (PVC) and rubber to avoid chemical burns of the boat material.
There are several classes of materials, each with its own advantages and disadvantages depending on the budget and the required service life.
- 🛡️ Epoxy resins create a monolithic, absolutely waterproof layer of high strength, but require precise compliance with the proportions when mixing.
- 🪵 Oil impregnations (such as olive oil or flaxseed oil) - penetrate deeply into the structure, but require regular updating and dry for a long time.
- 🎨 Yacht varnishes - have good elasticity and UV protection, but are much more expensive than analogues for internal work.
- 🧱 Polyurethane formulations - are characterized by high wear resistance and resistance to abrasion, which is critical for the bottom.
When choosing between these options, it is worth remembering that Only epoxy resin is able to turn ordinary plywood into a material comparable in moisture resistance to plasticcompletely blocking the capillary water suction.
Surface Preparation: The Foundation of Durability
The quality of the final coverage depends 80% on how well the pre-preparation of the sheets was done. enamel Or the resin will not stick to dusty, greasy or wet surfaces, peeling off at the first load, and the process begins with careful grinding, which allows you to open the wood pores to better absorb the primer.
You should use sandpaper of medium grain, sequentially passing through all planes and, most importantly, on the ends. cut-off These are the most vulnerable places where water is absorbed most quickly, so they need to be given the utmost attention.
☑️ Preparation of plywood for impregnation
After machining, you need to degrease, removing any traces of oils that may have been on the sheet during production or storage. acetone or white-spiritThey quickly disappear without leaving any traces.
It is important to make sure that the humidity of the wood is minimal before work begins, otherwise moisture will remain "locked" inside, causing rot from the inside. If you are working with new plywood, let it lie in a warm dry room for a few days for acclimatization.
Technology of processing epoxy resin
The most reliable method that professionals choose to create unsinkable elements is lamination with epoxy resin, which requires carefulness, because it is a process that requires a lot of care. epoxy It has a limited life after mixing with the hardener. First, you need to prepare the composition strictly following the manufacturer's instructions, since a violation of the proportions will cause the resin to remain sticky or become brittle.
The first layer is best applied with a brush with a hard bristles, actively rubbing the composition into the wood to maximize saturation of the top layer. Subsequent layers are applied after partial polymerization of the previous one, when the surface becomes matte, but still sticky, which ensures the monolithic coating.
⚠️ Warning: When working with epoxy resins, be sure to use a respirator and gloves, as the pairs can cause severe irritation of the airways, and getting on the skin is difficult to wash off.
And to reinforce the structure, we often use fiberglass, which fits between the layers of the resin, creating a reinforcement frame. compositeHe is not afraid of water or stones.
The Secret to Perfect Mixing
Thoroughly stir the components for at least 3-5 minutes, scraping the composition from the walls and bottom of the container, as it is at the bottom that the unhardened hardener often remains.
The time of full polymerization can vary from 24 hours to several days depending on the ambient temperature and the type of hardener. Don't rush to assemble the boat immediately after drying "on the stick", let the chemical processes complete for maximum strength.
Alternative methods: olive oil and yacht lacquer
If working with epoxy seems too complicated or expensive, you can turn to classic protection methods, proven by decades of shipbuilding. olipha or boiled flaxseed oil penetrate deep into the fibers, polymerizing inside and displacing water, but this process is long and requires patience.
The technique of cooking plywood in oil is to heat the sheets in a hot olifer container, allowing the compound to penetrate the entire depth of the sheet, which turns ordinary birch plywood into a material that can stay in water for years without signs of destruction.
Yacht lacquer is a more modern and easy-to-use solution, forming an elastic glossy film on the surface, and it is excellent at protecting against ultraviolet light, which often breaks down binders in plywood, causing veneer to detach.
| Parameter | Epoxy resin | Olifa/Oil | Yacht lacquer |
|---|---|---|---|
| Water resistance | Absolute. | High (when boiled) | High. |
| Difficulty of application | High. | Medium | Low. |
| Drying time | 24-48 hours | 3-7 days | 12:24 hours. |
| Cost | High. | Low. | Medium |
The choice between these methods depends on your skills and the availability of free time, as oil impregnation requires reusable application with prolonged drying between the layers.
Protecting ends and edges: critical areas
Experienced boat mechanics know that moisture penetrates into plywood mainly through open endsIf the side surfaces can be protected with a relatively thin layer of varnish, the edges require increased attention and multilayer processing.
It is recommended to smear the ends with an epoxy compound or thick oil impregnation at least 5-7 times, waiting for the complete absorption of each previous layer. Some craftsmen even round the sharp edges of the ends before processing to reduce the risk of mechanically chipping the coating during assembly and disassembly.
⚠️ Warning: Never leave the ends of plywood without careful sealing, as it is from them that the layering of the material begins when wet.
You can use it additionally. flat-foot It's an epoxy-based solution to fill in the large pores and bumps in the cuts before the final varnishing, and it creates a smooth surface that's easier to clean out the mud and mud after fishing.
Drying and storage of processed elements
Proper drying is the final and equally important step, because a violation of the temperature regime can spoil all work. varnish Or tar.
The optimum temperature for polymerization of most compounds is in the range of +20 to +25 degrees Celsius. At lower temperatures, the process can be delayed, and at high temperatures, the composition can boil or become covered with bubbles.
Full polymerization of chemical compounds takes up to 7 days, even if the surface appears dry to the touch after a day.
Store the finished floor sections or transverses until assembly should be in a horizontal position, eliminating any deflection until the coating has gained final hardness. If you fold them vertically too early, you can get deformation that will not be corrected.
Regular inspection of the coating at the beginning and end of the season will allow you to notice small scratches in time and restore the protective layer before the water reaches the wood, you just need to have a small repair kit with a can of the composition used and a brush.
Frequently Asked Questions (FAQ)
Can I use a regular construction oil for a boat?
You can use regular olifu, but the effect will be temporary. For a boat, it is better to use natural linen olifu or special compounds with the addition of siccatives, since construction options often contain many solvents and few protective oils.
How many layers of epoxy should be applied?
The best approach is to apply 3-4 layers of epoxy, the first two layers serve as soil and absorb into the tree, and the next one creates a strong protective crust, and often put fiberglass between the layers for reinforcement.
Do I need to grind the plywood after each layer?
Yes, light sanding (interlayer grinding) is necessary to improve the adhesion of the next layer and remove the pile that rises from moisture. Use fine sandpaper (grain 240-320) and be sure to remove the dust before applying the new layer.
How long does plywood dry after oil treatment?
The drying process of oiled plywood can take from 2 to 4 weeks, depending on the thickness of the sheet and the humidity of the air. The oil dries not by evaporation, but by oxidation, so air access to the surface should be free from all sides.