What is ALEXSEAL FINE FILLER 303 and why choose it?
ALEXSEAL Fine Filler 303 is a solvent-free, epoxy-based filler designed for professional use in high-performance coating systems. When mixed with ALEXSEAL C3034 Fine Filler 303 Converter, it cures without shrinking into a water-resistant, solid coating. It is intended to be used between ALEXSEAL Fairing Compounds and the primers ALEXSEAL Super Build 302 or ALEXSEAL Finish Primer 442, delivering fast drying, excellent sanding properties and high mechanical resistance.
The system can be applied above or below the waterline on correctly prepared substrates, making it suitable for demanding marine and industrial serial painting applications where a smooth and durable surface is required.
Main features
- Epoxy-based, solvent-free formulation: mixed material contains 100% volume solids.
- No shrinkage on cure: forms a solid, water-resistant coating.
- High mechanical resistance: cured film offers superior mechanical resistance values.
- Fast drying and easy sanding: designed for efficient processing with excellent sanding characteristics.
- Versatile application range: suitable for fairing imperfections on surfaces both above and below the waterline (below the waterline it must be sealed with Super Build 302 and/or Finish Primer 442).
- Controlled mixing: base and converter have different colors to visually control mixing; final mix should be homogeneous.
- Professional application: optimized for use with trowels, spatulas and straight-edge tools on properly prepared ALEXSEAL primers, fillers, gel coat and raw resin lay-ups.
Technical specifications
Color
- Color of mixture: Sand
- Base material: Light Gray
- Converter (C3034): Beige
C3034 Fine Filler 303 Converter (hardener)
- Chemical nature: hardener based on polyamine / amino adduct
- Intended use: component of the ALEXSEAL Fine Filler 303 system for industrial serial painting
COVERAGE
- Volume solids (mixed material): 100 %
Coverage depends on fairing depth and surface size. Indicative values (base + converter):
- Theoretical coverage: 20 m²/liter; 76 m²/gal; 818 sq. ft./gal @ 50 µm (2 mils) DFT
- Practical coverage: 20 m²/liter; 76 m²/gal; 818 sq. ft./gal @ 50 µm (2 mils) DFT
Packaging / trade names
- P3033 ALEXSEAL Fine Filler 303 (base): 2 Gal (or 1 Gal in EN version)
- C3034 ALEXSEAL Fine Filler 303 Converter: 1 Gal (or ½ Gal in EN version)
Mixing ratio
- By volume: 2 parts P3033 ALEXSEAL Fine Filler 303 (base) : 1 part C3034 ALEXSEAL Fine Filler 303 Converter
- Reduction: ALEXSEAL Fine Filler 303 must not be reduced / thinned.
Substrate preparation
- Substrate must be clean, dry and free from dust, grease, oil and other contamination.
- Can be used as a high-film surfacer over ALEXSEAL primers and fillers, or over gel coat and raw resin lay-up.
- Sanding before application:
- Primed/fairing surfaces: P80–P150 grit.
- Fiberglass resin: P36–P60 grit and/or sandblasting; surface and profile bottoms should be dull and abraded with no shiny spots.
- Before topcoating, seal with ALEXSEAL Super Build 302 and ALEXSEAL Finish Primer 442.
Application
- Application tools: trowels, spatulas, straight-edge materials.
- Mix base and converter until a completely homogeneous sand-colored filler is obtained. Avoid air bubbles.
- Mix mechanically with slow-turning dough mixers or manually. Do not use drill mixers.
- Apply in thin layers by spatula or trowel, building to the desired thickness, then pull off excess with a straight edge to prevent air pockets.
- Equipment cleaning: use ALEXSEAL R4042 Epoxy Primer Reducer.
- Sanding after cure: block sand with P100–P150 grit; finishing with P150 or finer helps avoid sand-scratch print-through in the final system.
Pot life and drying times (mixed product)
Optimal application climate: 15–30 °C (60–85 °F), 40–80 % RH.
| Substrate temperature | Pot life (approx.) | Dry to sand | Tape dry | Fully cured |
|---|
| 15 °C (60 °F) | 2 h | 48 h | 48 h | 9 days |
| 20 °C (68 °F) | 90 min | 24 h | 24 h | 7 days |
| 25 °C (77 °F) | 45 min | 18 h | 18 h | 5 days |
| 30 °C (85 °F) | 30 min | 12 h | 12 h | 3½ days |
Minimum drying temperature during cure: 15 °C (60 °F). Ideal temperature: 25 °C (77 °F). Application conditions should be at least 3 °C (5.4 °F) above dew point.
Recoating ALEXSEAL Fine Filler 303 over itself should follow the minimum dry-to-sand times. Scratch sanding with P80–P120 grit is recommended to ensure intercoat adhesion. Overcoating with ALEXSEAL Super Build 302 and ALEXSEAL Finish Primer 442 is possible after the minimum time and block sanding with P100–P150 grit.
Applications and use cases
- Fairing and surfacing: evening out imperfections on appropriately prepared surfaces in marine or industrial serial painting environments.
- Below-waterline work: suitable for areas below the waterline when subsequently sealed with ALEXSEAL Super Build 302 and/or ALEXSEAL Finish Primer 442.
- Over ALEXSEAL systems: designed to be used over compatible ALEXSEAL primers and fairing compounds as part of a complete coating build-up.
- Fiberglass structures: suitable on abraded fiberglass resin profiles where a smooth, solid, water-resistant coating is required.
FAQ
1. What is ALEXSEAL C3034 Fine Filler 303 Converter?
It is the polyamine-based hardener component that is mixed with P3033 ALEXSEAL Fine Filler 303 base in a 2:1 volume ratio to initiate curing.
2. Can Fine Filler 303 be used below the waterline?
Yes. It can be used above and below the waterline on properly prepared surfaces, but below the waterline it must be sealed with ALEXSEAL Super Build 302 and/or ALEXSEAL Finish Primer 442 prior to topcoating.
3. Do I need to thin ALEXSEAL Fine Filler 303?
No. ALEXSEAL Fine Filler 303 must not be reduced or thinned.
4. How should the substrate be prepared before application?
The surface must be clean, dry and free from dust, grease, oil and other contamination. Sand primed or faired surfaces with P80–P150 grit; grind fiberglass with P36–P60 grit and/or sandblast until dull with no shiny spots.
5. Which tools are recommended for application?
Apply using trowels, spatulas or straight-edge tools, building in thin layers and pulling the product out with a straight edge to avoid air pockets.
6. What are the typical drying times before sanding?
At 20 °C (68 °F) the product is typically dry to sand after approximately 24 hours; at 25 °C (77 °F) after about 18 hours. See the drying table above for other temperatures.
7. How should I sand the cured Fine Filler 303?
Block sand with P100–P150 grit. Finishing with P150 or finer helps prevent sand-scratch print-through in the final coating system.
8. Is the converter hazardous?
The C3034 Converter is classified as causing severe skin burns and eye damage, may cause an allergic skin reaction and is very toxic to aquatic life with long lasting effects. Appropriate protective measures must be used; see the personal protection section below.
Section 14 – Transport information
- UN number (ADR / IMDG / IATA): UN 3066
- UN proper shipping name: PAINT RELATED MATERIAL
- Transport hazard class: Class 8 (corrosive)
- Packing group: II
- ADR classification code: C9
- Hazard identification number (ADR): 80
- Tunnel restriction code: (E)
- IMDG EmS code: F-A, S-B
- IATA packing instructions: 855 (cargo aircraft), 851 (passenger aircraft), Y840 (LQ)
- Environmentally hazardous / marine pollutant: yes
- On-site transport advice: always transport in closed, upright and secure containers; ensure personnel know the procedures in case of incident or spillage.
Section 8 – Individual protection measures
Engineering controls
- Provide good ventilation, preferably with local exhaust and adequate general extraction.
- If ventilation does not keep particulates below applicable limits, suitable respiratory protection must be worn.
Personal protective equipment
- Eye/face protection: wear safety goggles to protect against splashes.
- Hand protection:
- Use chemical-resistant protective gloves compliant with EN 374.
- Recommended materials for short-term contact (splash protection): nitrile rubber or neoprene.
- Minimum material thickness: > 0.4 mm; breakthrough time: > 480 minutes.
- Check glove suitability for the specific workplace; replace damaged or worn gloves immediately.
- Use preventive skin protection cream and wash contaminated skin immediately.
- Skin and body protection: wear work clothing as usual in the chemical industry.
- Respiratory protection: normally not required, but avoid breathing vapours, dust from sanding, particulates or spray mist.
General safety and hygiene measures
- Do not eat, drink or smoke during use.
- Avoid contact with skin, eyes and clothing.
- Do not breathe dust; avoid inhalation of vapours, spray mist and sanding dust.
- Keep away from drains; prevent product from entering watercourses.
*Contenido generado por IA
