HS BASE COAT

What is ALEXSEAL HS Base Coat and why choose it?

ALEXSEAL HS Base Coat is a professional two-component, high-solid (HS) polyurethane base coat designed for efficient spray applications on yachts. It offers fast drying and excellent hiding power. When sealed with an ALEXSEAL Clear Coat, the system delivers outstanding chemical and mechanical resistance, high gloss and very good color stability, making it suitable for demanding marine finishes on areas not permanently immersed in water.

Main features

• High-solid two-component polyurethane for durable yacht coatings.
• Fast-drying formulation that is tape-dry after a few hours (depending on temperature) to support multi-color schemes and efficient workflows.
• Excellent hiding power for uniform color appearance; multiple coats can be used where extra coverage is required.
• Optimized for clear coat systems: when overcoated with ALEXSEAL Clear Coat, the system provides excellent chemical and mechanical resistance and a very glossy, color-stable finish.
• Spray-application only, compatible with conventional and HVLP equipment.
• Flexible use on internal and external yacht areas not subject to permanent water immersion.
• Available in standard factory-packaged colors for consistent shade reproduction.

Technical specifications

Product type and composition

• Type: Two-component polyurethane HS base coat.
• Chemical nature: Mixture of synthetic resins, organic solvents and pigments.
• Volume solids (catalyzed, without reduction): 55 – 70 %, depending on color.

Mixing and components

• Base material: Hxxxx ALEXSEAL HS Base Coat, 0.75 gal.
• Converter: C5047 ALEXSEAL HS Base Coat Converter, 1 QT.
• Activators:
  • R5541 ALEXSEAL HS Base Activator Medium, 1 QT.
  • R5521 ALEXSEAL HS Base Activator Slow, 1 QT.
• Standard mixing ratio (by volume): 3 : 1 : 1 (Base Coat Hxxxx : Converter C5047 : Activator Rxxxx).
• The amount of ALEXSEAL HS Activator (activated reducer) is fixed and must not be changed.
• Mixed material must be filtered through a suitable paint filter before application.
• When ALEXSEAL Topcoat 501 Clear Coat is applied over the HS Base Coat, R5541 ALEXSEAL HS Base Activator Medium must be used (not R5521 Slow) during base coat application.

Application parameters

• Application method: Spray only.
• Recommended system: HS Base Coat + ALEXSEAL Topcoat Clear / Clear Coat.
• Viscosity of spray-ready material:
  • Zahn #2: approx. 15 – 19 s.
  • DIN 4 cup 4 mm: approx. 13 – 15 s.
  • ISO 3: approx. 70 – 80 s.
• Spray gun setup (conventional & HVLP):
  • Nozzle size, gravity gun: 1.0 – 1.3 mm (0.040 – 0.051 in).
  • Nozzle size, siphon cup: 1.0 – 1.3 mm (0.040 – 0.051 in).
  • Fluid nozzle size, pressure pot: 0.8 – 1.0 mm (0.032 – 0.040 in).
  • Atomizing pressure: 2.5 – 4.0 bar (40 – 60 PSI).
  • Pot pressure: 0.5 – 1.2 bar (7 – 16 PSI).

Film thickness and coverage

• Application steps:
  1. Apply 1–2 coats HS Base Coat by spray to a wet film thickness (WFT) of 40 – 60 µm per coat (1.6 – 3.2 mils).
  2. For a single-coat application this achieves a dry film thickness (DFT) of 20 – 30 µm (0.8 – 1.2 mils).
  3. Maximum recommended cumulative thickness in one spray process: 120 µm (4.7 mils) WFT or 75 µm (3.0 mils) DFT.
• Coverage (@ 50 µm / 2 mils DFT, base + converter only):
  • Theoretical: 11 m²/L; 42 m²/gal; 462 sq. ft./gal.
  • Practical with conventional air spray: 5.5 m²/L; 20.8 m²/gal; 224 sq. ft./gal.
  • Practical with HVLP: 6.8 m²/L; 26 m²/gal; 280 sq. ft./gal.
• Activator is added as a percentage of the total quantity of base plus converter.

Drying and pot life

Optimal application environment: 15 – 30 °C (60 – 85 °F) and 40 – 80 % relative humidity. Minimum application conditions should be at least 3 °C (5.4 °F) above dew point.

Values above are approximate and influenced by surface temperature, air flow, direct or indirect sunlight, solvent choice and film thickness. Ideal drying temperature is 25 °C (77 °F). Minimum temperature during drying is 15 °C (60 °F).

Physical and hazardous properties (summary)

• Physical state: Liquid (20 – 25 °C, 1,013 hPa).
• Colour: According to product name.
• Odour: Characteristic.
• Boiling range: approx. 120 °C.
• Flash point: 25 °C (ISO 13736).
• Upper explosion limit: 10 % (V); lower explosion limit: 1 % (V).
• Auto-ignition temperature: > 400 °C.
• Density: approx. 1.3 g/cm³ (20 °C).
• Water solubility: Insoluble; immiscible with water.
• Classification (Regulation (EC) No 1272/2008):
  • Flammable liquid, Category 3 (H226: Flammable liquid and vapour).
  • Specific target organ toxicity, single exposure, Category 3, central nervous system (H336: May cause drowsiness or dizziness).
  • EUH066: Repeated exposure may cause skin dryness or cracking.

Substrate preparation

• Substrate must be clean, dry and free from dust, grease, oil and other contamination.
• Use ALEXSEAL Finish Primer 442 to achieve optimum performance and adhesion.
• Final sanding of ALEXSEAL Finish Primer 442: 280, 320 or 400 grit sandpaper to a smooth, fine finish.
• Apply ALEXSEAL HS Base Coat over the sanded primer within 4 days (or within 2 days if the primer is exposed outside) to ensure adhesion.

Applications and use cases

Range of application

• Designed for the ALEXSEAL HS Base Coat / Clear Coat system on yachts.
• Suitable for internal and external yacht areas that are not subject to permanent water immersion.

Typical use cases

• Topside and superstructure color coats that will be sealed with clear coat for high gloss and durability.
• Multi-color yacht schemes: fast tape-dry (approx. 4 hours at 20 °C) enables efficient masking and application of several colors before clear coating the complete surface.
• Spot repairs and spare parts: follow the original overcoating intervals to avoid color differences and use fading techniques instead of sharp edges.
• Industrial serial painting where professional spray equipment and controlled drying conditions are available.

FAQ

1. On which areas of a yacht can HS Base Coat be used?

The ALEXSEAL HS Base Coat / Clear Coat system can be used on interior and exterior yacht areas that are not permanently immersed in water.

2. How many coats are recommended?

Apply 1–2 coats of HS Base Coat at 40 – 60 µm WFT per coat. Multiple coats may be needed for full hide with some colors, but the total film thickness in one spray process should not exceed 120 µm WFT or 75 µm DFT.

3. What is the correct mixing ratio?

The standard mixing ratio by volume is 3 parts HS Base Coat (Hxxxx) : 1 part Converter C5047 : 1 part HS Base Activator (R5541 Medium or R5521 Slow). The activator amount is fixed and must not be altered.

4. When can I overcoat with ALEXSEAL Clear Coat?

Depending on temperature, ALEXSEAL Clear Coat can typically be applied after 2–4 hours (minimum) and within 3 days (maximum). Refer to the drying table for precise intervals at 15–30 °C.

5. Do I have to sand between base coat and clear coat?

If the clear coat is applied within the specified overcoating window, sanding is not required. If the maximum recoat time is exceeded, sand the surface with fine grade abrasive and clean with ALEXSEAL Wipe Down Solvent A9049 before clear coating.

6. Is HS Base Coat suitable for brush or roller application?

No. The product is designed for spray application only.

7. What happens if I sand through the clear coat into the base coat?

Breaking through the clear coat during sanding can affect or change the color of the HS Base Coat. Care must be taken to avoid sanding through the clear.

8. Can HS Base Coat be used without a clear coat?

The technical documentation describes the HS Base Coat as part of a system that is sealed with ALEXSEAL Clear Coat for optimal chemical and mechanical resistance, gloss and color stability. Consultar ficha técnica del fabricante.

9. How should I handle small repairs?

For sport repair and spare parts, follow the original overcoating intervals to avoid color differences and work with a fading technique rather than sharp edges.

10. What colors are available?

HS Base Coat is supplied in standard factory-packaged colors. Specific color and part numbers are listed in the ALEXSEAL color card or product overview.

Section 14 – Transport information

• UN number / ID number: UN 1263.
• UN proper shipping name: PAINT.
• Transport hazard class: Class 3 (Flammable liquids) for ADR, IMDG and IATA.
• Packing group: III (ADR, IMDG, IATA).
• Classification code (ADR): F1.
• Hazard identification number (ADR): 30.
• Labels: 3 (Flammable liquid).
• Tunnel restriction code (ADR): (D/E).
• EmS code (IMDG): F-E, S-E.
• Environmental hazards:
  • ADR: Not classified as environmentally hazardous.
  • IMDG: Not classified as a marine pollutant.
• Special precautions:
  • Within user premises, always transport in closed, upright and secure containers.
  • Ensure persons handling the containers know the procedures in case of incident or spillage.
  • ADR: Receptacles under 450 L are not subject to ADR section 2.2.3.1.5.
  • IMDG: Receptacles under 450 L are not subject to IMDG chapters 4.1, 5.2 and 6.1 (2.3.2.5).
• Maritime transport in bulk (IMO instruments): Not applicable for the product as supplied.

Section 8 – Personal protective measures

Exposure controls and general safety

• Provide adequate ventilation through local exhaust and general extraction. If aerosol and solvent vapour concentrations exceed occupational exposure limits, suitable respiratory protection is required.
• Avoid breathing mist, vapours, dust from sanding and spray mist.
• Do not eat, drink or smoke in the application area.
• Prevent creation of flammable or explosive vapour concentrations in air and keep away from all ignition sources.

Recommended personal protective equipment (PPE)

• Eye and face protection: Wear safety goggles to protect against solvent splashes.
• Hand protection:
  • Use chemical-resistant protective gloves tested according to EN 374.
  • Recommended materials for short-term contact (splash protection): nitrile rubber or neoprene.
  • Minimum material thickness: > 0.4 mm; breakthrough time: > 480 minutes.
  • Inspect gloves for suitability and damage before use and replace immediately if worn or damaged.
• Skin and body protection: Wear appropriate protective clothing, adapted if there is a risk of explosive atmospheres.
• Respiratory protection:
  • If solvent concentrations exceed limit values, wear a suitable breathing apparatus (half mask with cartridge or air-fed system).
  • During spraying in booths, operators working inside should use compressed air-fed respirators until particulate and vapour levels are below exposure limits.

Additional handling and storage precautions

• Keep away from oxidizing agents, strong acids and strong alkalis.
• Store in tightly closed containers, in a cool, dry, well-ventilated place, away from heat and direct sunlight.
• Recommended storage temperature: 5 – 35 °C.
• Ensure proper earthing and use anti-static footwear and clothing when transferring material between containers. Avoid sparking tools.

*Contenido generado por IA