Painting a outboard motor is not just an aesthetic procedure, but a critical step in corrosion protection, especially if you operate the appliance in salt water or store it outdoors. Incorrect paint selection or violation of application technology can lead to the use of the appliance. rust-proof In this article, we will discuss which compounds are suitable for different types of engines.two-stroke, four-stroke, suspended and stationary), how to properly prepare the surface and avoid typical errors.
We'll pay special attention. anticorrosion paints - not all metal compounds are equally effective in aggressive aqueous environments. For example, conventional automotive enamel will last the maximum season, while specialized marine paints based on epoxy resins or zinc protect the engine on the ground. 5-7 years with proper applicationWe also consider the nuances of working with aluminum and steel cases, because they require different primers and preparation methods.
Why you can not paint the outboard motor with ordinary paint
Many owners of PVC boats or aluminum vessels are trying to save money by using car enamel or metal paint from construction stores. accelerated And it's a year from now, and it's a matter of the specifics of the operation.
- ๐ Constant contact with water Even freshwater bodies contain minerals and microorganisms that destroy inappropriate coatings.
- ๐ง Salt water 5-10 times more aggressive than fresh water due to electrochemical corrosion (especially dangerous for aluminum).
- โ๏ธ UV radiation Ordinary paints burn out, crack and lose their protective properties under the sun.
- ๐ฅ Temperature variations The motor is heated to 60-90ยฐC during operation and cools in water, which leads to cracking of inelastic coatings.
Specialized sea-paint contain additives that:
- ๐ก๏ธ Inhibit corrosion (zinc, aluminum powder).
- ๐งด They have a high adhesion to wet and greasy surfaces.
- ๐ They withstand cyclic loads (metal expansion/compression).
โ ๏ธ Attention: Water-based paints (acrylic, latex) are categorically not suitable for outboard motors! They absorb moisture and promote rusting under the coating.
Top 5 paints for outboard motors: comparison and features
There are dozens of trains on the market, but we've selected time-tested and water-tested options. ISO 12944 (protection against corrosion in marine conditions) and have certificates for use on boats.
| Name of the paint | Type of base | Term of protection | Suitable for | Price (per 1 l) |
|---|---|---|---|---|
| International Interprotect 2000E | epoxy | 5-7 years | Aluminum, steel, underwater parts | ~3 500 โฝ |
| Hempel Hempadur 15500 | Epoxy (with zinc) | 6-8 years | Steel motors, salt water | ~4 200 โฝ |
| SeaLine Antifouling | Acrylic (with biocides) | 2โ3 years | Underwater parts, protection against fouling | ~2 800 โฝ |
| Rust-Oleum Marine Coating | Alkyd (modified) | 3-4 years | Budget option for fresh water | ~1 900 โฝ |
| Jotun Penguard HB | Epoxy (highly hard) | 8 years | Professional use, harsh conditions | ~5 500 โฝ |
For most motorists, the motors Yamaha F25, Mercury 15 or Tohatsu 9.8 The best choice will be International Interprotect or Hempel Hempadur If your motor is constantly in salt water (for example, in Crimea or the Far East), it is worth considering. Jotun Penguard HB despite its high price.
Important: For aluminium engines (Honda BF5, Suzuki DF6> can not use paints with a high content of zinc - this will lead to electroplatingInstead, choose aluminum powdered compounds or specialized primers as Alumiprep 33 from International.
Before buying, check the compatibility of the paint with the primer! some epoxy formulations require branded primers of the same manufacturer for maximum adhesion.
Preparation of the engine for painting: step-by-step instructions
The quality of the paint depends on the surface preparation, and neglecting this stage is the main reason why the paint peels off or bubbles after a few months. Mercury 20 with traces of rust and old coating.
Remove old coating (grinding machine/sandjet) |Treat rust with a converter (zincary, Fertan>) | Degrease the surface (White Spirit, Acetone>)|Place a primer (for aluminum/steel)|Place deep scratches (epoxy putty)|Place the surface with sandpaper P400โP600-->
Step 1 Removing old paint and rust
- ๐ง Smaller areas are fine. mechanical cleaning sandpaper
P80โP120) or a metal brush. - ๐จ For large motors (e.g., Yamaha 115more effectively sandblasting It removes even deep corrosion.
- โ๏ธ Chemical flushes (BODY 700, Abro>) speed up the process but require thorough degreasing after application.
Step 2: Corrosion treatment
Rust on steel parts (for example, on lower unit) treat rust converter:
1. Apply the composition with a brush or sprayer.2. Hold 15-30 minutes (until the surface is blackened).
3. Remove the residues with rags, wash with water.
4. Dry and degrease.
For aluminum, use specialized means as Alumiprep 33 They remove oxides without damaging the metal.
โ ๏ธ Attention: Never use sandpaper on aluminum motors without pre-treatment! abrasive particles can "imprint" into the soft metal and accelerate corrosion.
Step 3.
The ground is 50% success in paintingOther metals need different compounds:
- ๐น Aluminum: International Interprime 838 (zinc chromate epoxy soil).
- ๐น Steel: Hempel Galmet (zinc-filled soil).
- ๐น Mixed surfaces: Jotun Penguard Express (universal)
Apply the soil in 1-2 layers with intermediate drying (see manufacturer's instructions). 40-60 ฮผm.
Painting technology: brush, roller or spray gun?
The way you apply the paint affects not only the appearance, but also the durability of the coating. Let's look at the pros and cons of each method using the example of a motor. Tohatsu 30.
1. Brush
- โ Pros: Simplicity, accessibility, ability to paint hard-to-reach places (for example, cooling edges).
- โ Cons: You can see traces of hair, uneven layer thickness, the risk of bubbles.
Suitable for: Small engines (small engines)Honda BF2.3), local repairs, newcomers.
2.
- โ Pros: A smoother coating compared to the brush, high speed of work.
- โ Cons: It is difficult to paint corners and relief surfaces, skill is required.
Suitable for: Smooth surfaces (such as a motor pallet), experienced users.
3. Krascopult (HVLP)
- โ Pros: Perfectly smooth coating, minimal paint consumption, professional result.
- โ Cons: Expensive equipment, requires skills (pressure adjustment, paint viscosity).
Suitable for: Full painting of large motors (Mercury 150), commercial use.
How to set up a spray gun to paint the engine?
For epoxy paints (International Interprotect) use the following settings:
- Pressure at the inlet: 2.5-3.0 bar
- Duse size: 1.4โ1.6 mm
- Viscosity of paint (by viscometer DIN-4): 18-22 sec.
- Distance to the surface: 20-25 cm
Use a proprietary solvent for dilution (for example, International Thinners 218).
Recommendations for application:
- ๐จ Put paint in. 2-3 thin layers with intermediate drying (usually 4-6 hours with
20ยฐC). - ๐ก๏ธ The optimal temperature for painting:
15โ25ยฐCThe humidity is not higher than 70%. - ๐ Stir the paint before use and every 30 minutes while working.
The thickness of the final coating shall be 120โ150 ฮผm for epoxy paints and 80-100 ฮผm For acrylics, use a thickness gauge (e.g., a thickness gauge). Elcometer 300) for control.
Mistakes in painting the outboard motor and how to avoid them
Even experienced water-engineers sometimes make mistakes that negate all efforts, and here are the most common mistakes and ways to prevent them:
1. Painting on a dirty or greasy surface
If you don't degrease the engine after grinding, the paint will fall unevenly and start peeling off. White Spirit or specialized degreasing agents (Loctite 7063Check the surface cleanness "to the break" - glue the tape and sharply tear off: if there are dirt particles on it, the degreasing should be repeated.
Temperature disturbance
Epoxy paints require drying when 15โ25ยฐCIf the temperature is lower 10ยฐCThe polymerization slows down, and the coating will remain soft. 30ยฐC Use infrared heaters in the garage or move work to the warmer season.
3. Neglect of primer
Without soil, paint is only kept on the microscopic irregularities of the metal. Over time, the vibration of the motor and temperature changes lead to detachment. Interprime 838 Or similar corrosion will begin in 3-6 months.
4. A layer of paint too thick
One thick layer is worse than three thin ones. It dries longer, it can leak or crack. 30-50 ฮผmControl it with help. wet-thicknesser (for example, Elcometer 456).
5. Painting under direct sunlight
UV rays accelerate the drying of the top layer, while the bottom ones stay raw, which leads to internal stress and cracking, work in the shade or use a canopy.
โ ๏ธ Attention: Do not use a dryer or heat gun to accelerate drying of epoxy paints! This disrupts the polymerization process and leads to fragility of the coating. Only infrared heating at a distance of at least 50 cm.
Caring for a painted engine: how to extend the service life
The right paint is only half the battle, and the 5 to 7 years you're supposed to have, you need to have the right care, and that's what the experts recommend.
1. wash after each watering
- ๐ฟ Use it. freshwater And a soft sponge. For salt water, you have to rinse with detergent.Star brite Salt Off).
- โ Avoid high pressure washers โ they can damage the paint at the joints and edges of the cooling.
2. Protection against UV radiation
Even the paints of the sea burn out over time. If the motor is stored outdoors, use:
- ๐งด Wax polyroles (Collinite 885) - provide an additional protective layer.
- ๐ ๏ธ Breathable material covers (Sunbrella) - prevent overheating.
3. Microdamage check
Check the engine every 3-6 months for:
- ๐ Scratching (especially on the bottom of lower unit).
- ๐ฅ Crushed from impacts on a pier or rocks.
- ๐จ Flows or turbidity of paint (a sign of the beginning of corrosion under the layer).
If you find defects, clean them and paint them, and you can do local repairs. Rust-Oleum Marine Touch-Up.
4. Season storage
- ๐ Ideally - dry ventilated room with temperature
5โ20ยฐC. - ๐ซ Do not store the engine in a wet basement or garage without ventilation.
- ๐ Remove the battery and treat the terminals LIQUI MOLY Batterie-Pol-Fett.
If the motor is stored on the boat in winter, install a pallet with silica gel under it - this will reduce condensation and the risk of corrosion.
Painting of aluminum engines: some nuances
Aluminum engines (Honda, Suzuki, Parsun) require special treatment because of the high chemical activity of the metal, errors are more expensive than steel - corrosion can destroy the body in 1-2 seasons.
1. Selection of primer
Aluminum is oxidized in air, forming a film that interferes with the adhesion of the paint.
- ๐งช Acid primers (Wash Primer) - poison oxides and create a solid base.
- ๐ก๏ธ Epoxy soils (International Interprime 838) - insulate the metal from moisture.
You can't: Use soils for steel (for example, high in zinc) โ they will cause galvanic corrosion.
Preparation of the surface
Aluminum should be painted before:
- Process it. alkaline degreaser (Fosroc Dekontaminator).
- Put it on. oxide converter (Alodine 1201).
- Wash with distilled water and dry.
3. Paint selection
For aluminum, suitable:
- ๐จ International Perfection - two-component polyurethane paint.
- ๐จ Awlgrip Topcoat High-gloss coating for yachts (suitable for motors).
Avoid: Paint high in copper or zinc โ they accelerate the corrosion of aluminum.
โ ๏ธ Attention: If the aluminum engine already has foci of corrosion (white powder), before painting be sure to process them. Alumiprep 33 and apply layer epoxy putty3M Marine Filler).
FAQ: Frequent questions about painting outboard motors
Can I paint the engine with a can?
Yes, but only for small motors.Parsun 2.6, Honda BF2.3) or local repairs. Use canisters with epoxy (for example, Rust-Oleum Marine SprayThe main disadvantages are:
- Uneven coating (see "orange peel").
- High consumption per motor Mercury 15 It'll take 4-5 cylinders.
- It is difficult to control the thickness of the layer.
For best results, apply the paint in 3-4 thin layers with intermediate drying for 15-20 minutes.
How much paint does it dry before the engine is launched?
It depends on the type of paint and temperature:
- Epoxy paints (International Interprotect):
7 daysupon20ยฐC(complete polymerization). - Polyurethane (Awlgrip):
5-7 days. - Acrylic (SeaLine):
3-5 days.
If the temperature is lower 15ยฐCThe drying time increases by 1.5-2 times. You can not accelerate the process with a hairdryer!
How to remove old paint from the engine without sandblasting?
If there is no sandblasting, use a combination of methods:
- Chemical flushingPut it on. BODY 700 or Abro PR-600Cover the film for 1-2 hours, then remove the softened paint with a spatula.
- Mechanical cleaning: Use a drill with a nozzle or petal disc (
P40โP80). - Thermal method: Construction dryer (
500โ600ยฐC) softens the paint and then it is easy to scrape off.
Thermal method is not suitable for aluminum - it can deform the metal!
How to paint the underwater part of the engine (dadewood, propeller)?
Underwater units require antifouling (antifouling), because they are deposited with algae and shellfish.
- International Micron Extra 2 Self-cleaning paint (life of service)
Seasons 2โ3). - SeaLine Antifouling Budgetary option for fresh water.
- Hempel Silic One Silicone paint (easily cleaned, suitable for salt water).
You don't need to paint the propeller, it makes it less fluid, instead, clean it regularly from fouling. scraper (metallic scratches the surface).
Can I paint the engine as new at home?
Yeah, but that would require:
- Complete disassembly of the engine (removal of the casing, lower unit, tiller).
- Sandblasting all the details.
- Use of professional materials (arts.Awlgrip, International).
- Painting in a paint chamber or a clean, temperature-controlled garage.
Without experience, it is better to go to a specialized workshop - mistakes will cost more than savings. Yamaha 60 - about 15 000โ25 000 โฝ (depending on condition).