FLAT FINISH 555 CONVERTER

What ALEXSEAL Flat Finish 555 Converter Is and Why Use It

ALEXSEAL Flat Finish 555 Converter (C5556) is a polyisocyanate-based hardener designed specifically for use with ALEXSEAL Flat Finish 555 two-component polyurethane topcoat. It activates the base material to create a durable, weather-resistant flat finish system suitable for professional marine and industrial environments. As part of the F Series, this converter is intended for industrial serial painting and professional use only.

Main Features

• Dedicated hardener for Flat Finish 555 – formulated to work with ALEXSEAL Flat Finish 555 base for consistent curing and film properties.
• Supports uniform flat appearance – enables application of even, flat topcoat layers when used according to the specified mixing and application parameters.
• High resistance in cured system – combined with Flat Finish 555 base, delivers high resistance values and strong adhesion on a wide range of substrates.
• Approved marine system – the Flat Finish 555 coating system has been approved under IMO Resolution MSC.307(88)-(FTP-Code 2010) as a marine paint with low flame-spread characteristics.
• Optimized for spray application – compatible with conventional, HVLP and pressure pot spray techniques with clearly defined nozzle sizes, pressures and viscosities.

Technical Specifications

Product and Composition

• Commercial product name: ALEXSEAL C5556-Flat Finish Converter
• Chemical nature: Hardener based on polyisocyanates
• Intended use: Industrial serial painting; converter for ALEXSEAL Flat Finish 555

Physical and Chemical Data (Converter)

• Physical state: Liquid (20–25 °C, 1,013 hPa)
• Colour: According to product name
• Odour: Characteristic
• Boiling point: approx. 120 °C
• Flash point: 35 °C (ISO 13736)
• Auto-ignition temperature: > 400 °C
• Lower explosion limit: 1.0 % (V)
• Upper explosion limit: 10.0 % (V)
• Water solubility: Insoluble; immiscible with water
• Vapour pressure: approx. 100 hPa (50 °C)
• Density: approx. 1.06 g/cm³ (20 °C)
• VOC content: 25 %, 270 g/l (Directive 2010/75/EU)

System Mix and Application Data (Flat Finish 555 System)

• Mixing ratio (by volume):
  • 7 parts ALEXSEAL Flat Finish 555 base
  • 1 part C5556 ALEXSEAL Flat Finish 555 Converter
  • 15–20 % R5557 ALEXSEAL Flat Finish 555 Reducer (by volume, based on total base + converter)
• Mixed material: Must be filtered before application.

Application Parameters (Spray Application of Mixed System)

• Recommended application method: Spraying (conventional, HVLP, pressure pot)
• Viscosity (reduced mix):
  • Zahn #2: approx. 24–33 s
  • DIN 4 cup 4 mm: approx. 20–30 s
• Gravity gun nozzle size: 1.6–2.0 mm (0.060–0.080 in) – conventional & HVLP
• Pressure pot fluid nozzle size: 1.2–1.5 mm (0.050–0.060 in) – conventional & HVLP
• Atomizing pressure: 2.0–4.0 bar (30–60 PSI) – conventional & HVLP
• Pot pressure: 1.0–2.0 bar (15–30 PSI) – conventional & HVLP
• Application: One cross coat to 125–150 µm (5–6 mil) wet film thickness, giving 60–100 µm (2–4 mil) dry film thickness. If required, repeat after 1 h at room temperature.

Environmental Conditions and Curing (Mixed System)

• Optimal application environment: 15–30 °C (60–85 °F); 40–80 % RH
• Minimum surface temperature: At least 3 °C (5.4 °F) above dew point
• Pot life (approx.):
  • 20 °C (68 °F): 75 min
  • 25 °C (77 °F): 60 min
  • 30 °C (85 °F): 45 min
  • 15 °C (60 °F): 90 min
• Tape dry (approx.):
  • 15 °C (60 °F): 4.5 h
  • 20 °C (68 °F): 3.5 h
  • 25 °C (77 °F): 3 h
  • 30 °C (85 °F): 2 h
• Fully cured (approx.):
  • 15 °C (60 °F): 7 days
  • 20 °C (68 °F): 5 days
  • 25 °C (77 °F): 3 days
  • 30 °C (85 °F): 2 days
• Recoat with ALEXSEAL Flat Finish 555 (spray):
  • 15 °C (60 °F): after 90 min
  • 20 °C (68 °F): after 75 min
  • 25 °C (77 °F): after 60 min
  • 30 °C (85 °F): after 45 min (max. 2 h)

Applications and Use Cases

• Marine interiors and exteriors: As part of the Flat Finish 555 system for ceiling panels and other panel applications in exterior areas where a low flame-spread, flat finish is required.
• Panel finishing on diverse substrates: Used with Flat Finish 555 base to finish panels made from a variety of materials, providing a uniform flat appearance and weather resistance.
• Industrial serial painting: Suitable for professional, repetitive coating operations in controlled spray booths and production lines.

FAQ – ALEXSEAL Flat Finish 555 Converter

1. Is ALEXSEAL Flat Finish 555 Converter for professional use only?

   Yes. Both the converter and the Flat Finish 555 system are specified for professional and industrial use only.

2. What is the correct mixing ratio with Flat Finish 555 base?

   Mix 7 parts Flat Finish 555 base with 1 part C5556 Converter by volume, then add 15–20 % R5557 Reducer based on the combined base and converter volume.

3. How should the mixed material be applied?

   Apply by spray as one cross coat to achieve 125–150 µm wet film thickness, resulting in 60–100 µm dry film thickness. If needed, a second application can be made after about 1 hour at room temperature.

4. What substrates can be coated with the Flat Finish 555 system?

   The system is used for finishing panels made from all kinds of materials, provided the substrate is clean, dry and properly pretreated.

5. What surface preparation is recommended before applying the system?

   The substrate must be clean, dry and free of dust, grease, oil and other contaminants. Flat Finish 555 can be applied directly over existing 442 Primer, with a recommended light sanding using P240–320.

6. How does temperature affect pot life and drying?

   Higher temperatures shorten pot life and drying times, while lower temperatures extend them. For example, pot life is about 75 min at 20 °C and 45 min at 30 °C. The minimum application temperature is 15 °C, with 25 °C cited as ideal.

7. Does the system have any special marine approvals?

   Yes. ALEXSEAL Flat Finish 555 has been approved by IMO Resolution MSC.307 (88)-(FTP-Code 2010) as a marine paint with low flame-spread characteristics.

8. Can gloss or appearance vary between applications?

   Yes. Final gloss can vary depending on airflow, temperature and humidity. Components should be painted under equal conditions to achieve a uniform flat appearance.

9. What should be done with leftover mixed material?

   Follow local regulations for disposal. Do not pour into drains or watercourses. Contaminated packaging should be emptied as far as possible and disposed of or reused in line with regional waste rules.

Section 14 – Transport Information (ALEXSEAL C5556-Flat Finish Converter)

UN Number and Proper Shipping Name

• UN number (ADR / IMDG / IATA): UN 1263
• UN proper shipping name: PAINT RELATED MATERIAL

Transport Hazard Class and Packing Group

• Transport hazard class: 3 (Flammable liquids)
• Packing group: III

ADR (Road Transport)

• Classification code: F1
• Hazard identification number: 30
• Label: 3
• Tunnel restriction code: (D/E)
• Environmentally hazardous: No
• Special remark: When transported within the user’s premises, always transport in closed, upright and secure containers. Ensure personnel handling the containers are aware of the procedures in case of incident or spillage.

IMDG (Sea Transport)

• Class: 3
• Packing group: III
• Label: 3
• EmS code: F-E, S-E
• Marine pollutant: No

IATA (Air Transport)

• Class: 3
• Packing group: III
• Labels: Flammable Liquids
• Packing instruction (cargo aircraft): 366
• Packing instruction (passenger aircraft): 355
• Packing instruction (LQ): Y344

Additional Transport Notes

The transport classifications above refer to the unpackaged material as described in the Safety Data Sheet. Actual transport classification can vary depending on packaging, transport mode and regional regulations. Maritime transport in bulk according to IMO instruments is not applicable for the product as supplied.

Section 8 – Personal Protective Measures (ALEXSEAL C5556-Flat Finish Converter)

Hazard Overview

• Flammable liquid and vapour.
• Harmful if inhaled.
• May cause an allergic skin reaction.
• May cause respiratory irritation.
• May cause drowsiness or dizziness.
• Repeated exposure may cause skin dryness or cracking.

Recommended Personal Protective Equipment

• Eye and face protection: Wear safety goggles to protect against solvent splashes.
• Hand protection:
  • Use chemical-resistant protective gloves tested in accordance with EN 374.
  • Recommended materials for short-term contact (splash protection): nitrile rubber or neoprene.
  • Minimum material thickness: > 0.4 mm.
  • Breakthrough time: > 480 min.
  • Gloves should always be checked for suitability for the specific workstation and replaced immediately if damaged or worn.
• Skin and body protection: Wear suitable protective clothing, adapted to the potential for explosive atmospheres in the work area.
• Respiratory protection:
  • For spraying: use an air-fed respirator.
  • For other operations in well-ventilated areas: air-fed respirators may be replaced by a combination charcoal and particulate filter mask (half-mask with cartridge or air-fed system), as appropriate.

Safe Handling and Exposure Controls

• Provide adequate local exhaust and general ventilation to keep vapour and particulate concentrations below applicable occupational exposure limits.
• Persons with a history of asthma, allergies, or chronic/recurrent respiratory disease should not work with this preparation.
• Avoid breathing mist or vapours and avoid inhaling dust from sanding, particulates or spray mists.
• Do not eat, drink or smoke in the application area.
• Avoid contact with skin, eyes and clothing; use suitable work practices and hygiene measures, including washing contaminated skin promptly.