Interfine 979 Acrylic Polysiloxane Topcoat is an acrylic paint, used as a topcoat. These markets include high-performance structures such as bridges, offshore structures and tank farms, where, in addition to general industrial and commercial steel structures, high-level decorative performance is also a primary requirement. A patented (US 6,281,321 and EP 0 941290), two-component high-performance high-solids inorganic hybrid topcoat that meets all current VOC content regulations and is free of unreacted isocyanate. Parameters on this page: dry film thickness 100–150 µm (4–6 mils), theoretical spreading rate 6.08 m²/L, number of components: two.
Data source: AKZONOBEL original Technical Data Sheet (TDS), "Interfine 979 Acrylic Polysiloxane Topcoat"; spreading rate and other values are converted from the TDS parameters, for selection reference only.
The above content is compiled from the manufacturer's datasheet and this site's parameter tables. For selection, coating systems and lead times, pleaseContact Usfor confirmation.
This page carries the full TDS for this product, translated from the manufacturer's original document. No file download is needed; for an original-language copy, send an enquiry.
| Volume Solids | 76% |
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| Dry Film Thickness | 100–150 µm (4–6 mils) |
| Theoretical Spreading Rate | 6.08 m²/L |
| VOC | 1.82 lb/gal (218 g/L) US EPA Method 24 16… |
| Density / Specific Gravity | 1.33 kg/L (11.1 lb/gal) |
| Number of Components | Two-component |
| Thinner | Do not exceed the thinning limits of local environmental regulations |
| Mixing Ratio | 4 parts : 1 part (by volume) |
| Colour / Appearance | A wide range of colours can be produced through the Chromascan tinting system |
For more Q&A on selection, application, acceptance and defect diagnosis, seeFAQsection.
A patented (US 6,281,321 and EP 0 941290), two-component high-performance high-solids inorganic hybrid topcoat that meets all current VOC content regulations and is free of unreacted isocyanate.
The colour and gloss retention of Interfine 979 is significantly better than typical polyurethane topcoats, and compared with the first-generation epoxy-modified polysiloxane topcoats, its gloss and colour retention is also better.
In addition, Interfine 979 has the same anti-corrosion performance as conventional epoxy technology, with superior mechanical properties.
Interfine 979 is a member of International Paint's premium polysiloxane topcoat range, with outstanding long-term colour and gloss retention. When used as part of a high-performance anti-corrosive system, it extends the life before the first maintenance. Interfine 979 is intended for market areas with high requirements for visual effect and aesthetic decoration. These markets include high-performance structures such as bridges, offshore structures and tank farms, where, in addition to general industrial and commercial steel structures, high-level decorative performance is also a primary requirement.
Providing the dual advantages of anti-corrosion performance and high-standard decorative appearance, Interfine 979 also means outstanding durability. This product can also function similarly to a conventional epoxy intermediate coat as an effective sealer, thereby reducing the total number of coats required for a multi-coat high-performance system - saving application cost and improving application efficiency.
| Colour | A wide range of colours can be produced through the Chromascan tinting system. |
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INTERFINE 979
| Gloss | |
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| Volume Solids | 76% |
| Typical thickness | Dry film 100–150 µm (4–6 mils), equivalent to wet film 132–197 µm (5.3–7.9 mils) |
| Theoretical Spreading Rate | At 125 µm dry film thickness and the stated volume solids: 6.08 m²/L; at 5 mils dry film thickness and the stated volume solids: 244 ft²/US gal |
| Practical Spreading Rate | Allowing for a suitable loss factor |
| Application Methods | Suitable for airless spray, air spray, brush, roller. Drying time; recommended topcoat recoat interval |
| Temperature | Surface Dry | Hard Dry | Minimum | Maximum |
| 5°C (41°F) | 6 h | 8 h | Unlimited¹ | |
| 15°C (59°F) | 4.5 h | 6 h | Unlimited¹ | |
| 25°C (77°F) | 3 h | 4 h | Unlimited¹ | |
| 40°C (104°F) | 1.5 h | 2.5 h | Unlimited¹ | |
¹ For other primers, refer to the "Interfine 979 Recommended Application Procedure" or Interspec for details.
The quoted drying times are measured at the stated temperature and 50% relative humidity.
For environments with high air temperature (>25 °C (77 °F)) and/or high relative humidity (>60%), an alternative hardener may be used, which improves the workability of the product. For details, refer to the "Product Characteristics" section.
| Flash point (typical) | Component A 32 °C (90 °F); Component B 55 °C (131 °F); mixed 35 °C (95 °F) |
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| Product weight | 1.33 kg/L (11.1 lb/gal) |
| Volatile Organic Compounds | 1.82 lb/gal (218 g/L) US EPA Method 24; 162 g/kg EU Solvent Emissions Directive content (EU Council Directive 2010/75/EU) 176 g/L China national standard GB 23985. Coating hazardous substances: GB 30981.2-S-Pb≤90-C compliant with GB 30981.2-2025. For more details, see the "Product Characteristics" section. |
All surfaces to be coated must be clean, dry and free of contaminants. Before application, all surfaces must be assessed and prepared in accordance with ISO 8504:2019.
Primed surfaces: Interfine 979 should always be applied over a recommended anti-corrosive paint. The primer surface should be dry and free of any contaminants, and Interfine 979 must be applied within the specified overcoating interval (see the relevant product data sheet).
Damaged and cracked areas shall be treated to the specified standard (e.g. Sa 2½ (ISO 8501-1:2007) or SSPC-SP10 abrasive blast cleaning, or SSPC-SP11 power tool cleaning) and the primer repaired before applying Interfine 979.
Zinc-primed substrates: before applying Interfine 979, ensure the primer surface is clean, dry and free of any contaminants and zinc salts. Before overcoating, ensure the zinc primer is fully cured.
| Mixing | This product is supplied in two containers forming one unit. Mix the two components in the specified ratio in one operation. Once mixed, use within the specified pot life. |
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(1) Stir the base (Component A) with a power mixer.
(2) Mix all of the curing agent (Component B) with the base (Component A) and stir thoroughly with a power mixer.
| Mixing ratio | 4 parts : 1 part (by volume) |
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| Pot life | 5°C (41°F) | 15°C (59°F) | 25°C (77°F) | 40°C (104°F) |
| 3.5 h | 2.5 h | 2 h | 1.5 h |
Note: the activation period applies to all grades of hardener.
| Suitable for airless spray | Recommended nozzle diameter 0.28–0.53 mm (11–21 mils); total paint pressure at the nozzle not less than 155 kg/cm² (2200 lb/in²) |
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| Air spray (conventional) | Recommended | Spray gun | DeVilbiss MBC or JGA |
| Air nozzle | 704 or 765 | ||
| Nozzle | E | ||
| Brush | Suitable | Typical thickness 50–75 µm (2–3 mil) | |
| Roller application | Suitable | Typical thickness 50–75 µm (2–3 mil) | |
| Thinner | International GTA007 | Do not exceed the thinning limits of local environmental regulations |
| Cleaner | Use a cleaning solvent that complies with local regulations. Consult the local representative for specific recommendations. |
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| Interruption of work | Do not leave paint in hoses, spray guns or spray equipment. Flush all equipment thoroughly with International thinner. Mixed paint should not be re-sealed; if work is interrupted for a long period, use freshly mixed paint when work resumes. |
| Cleaning | All equipment should be cleaned immediately after use with International thinner. Flushing spray equipment periodically during daily work is good practice. Cleaning frequency depends on the volume sprayed, temperature, spraying time, including delays, and other factors. |
All surplus paint and empty containers must be disposed of in accordance with the relevant local laws/regulations.
Before use, refer to the detailed Interfine 979 application procedure.
Gloss and surface smoothness depend on the application method. Mixing different application methods should be avoided where possible. Conventional air spray usually gives the optimum gloss and appearance.
When applying Interfine 979 by brush or roller, multiple coats are necessary to achieve the specified total system dry film thickness.
The product shall be thinned only with the recommended International GTA007 thinner. Use of other thinners, particularly alcohol- and ketone-containing thinners, will severely retard curing of the coating.
When the two components are mixed, the product temperature rises slightly; this is a characteristic of this product, caused by the exothermic chemical reaction.
Do not exceed the pot life; even if the paint is still liquid, it is not recommended to reuse it. Good working practice is to start application with unopened full containers. As the unfilled hardener component is moisture-sensitive, there is a risk of reaction with atmospheric moisture, which will adversely affect the performance of the final film. This phenomenon is more significant with fast-drying hardeners; the surface of the mixed product in the container is more prone to skinning, especially in warmer climates and/or high humidity.
The temperature of the surface to be coated must be at least 3 °C (5 °F) above the dew point.
When applying Interfine 979 in confined spaces, ensure adequate ventilation.
When spraying multiple coats of Interfine 979, care must be taken to apply a continuous wet film achieving a minimum dry film thickness of 100 µm (4 mils). Failure to do so may cause pinholes, reducing the final appearance and performance.
Interfine 979 achieves satisfactory curing at relative humidity between 40% and 85%. Curing is slower at low humidity and faster at high humidity.
Condensation on the surface during or after application will cause loss of gloss and a poor-quality film.
When overcoating after weathering or ageing, ensure the coating is thoroughly cleaned to remove all surface contaminants such as oil, grease, crystalline salts and road dust before applying the subsequent Interfine 979 coat.
Premature exposure to standing water may cause colour change, especially for dark colours and at low temperatures.
The intercoat adhesion to aged Interfine 979 is reduced compared with that to fresh coatings, but still meets the requirements of the intended use.
This product is not recommended for immersion service. If severe chemical or solvent splashes are likely, contact International Paint for information on suitability.
Note: VOC values are typical and for guidance only. They may vary with colour and general production tolerances.
Although the low-molecular-weight reactive additive becomes part of the film when cured under normal ambient conditions, analysis by EPA Method 24 shows that it also affects the VOC value.
Other hardeners to improve the workability of the product in warm and/or high relative humidity climates.
Overcoat with the recommended topcoat
| Temperature | Surface Dry | Hard Dry | Minimum | Maximum |
| 5°C (41°F) | 10 h | 24 h | Unlimited¹ | |
| 15°C (59°F) | 6 h | 12 h | Unlimited¹ | |
| 25°C (77°F) | 4 h | 8 h | Unlimited¹ | |
| 40°C (104°F) | 2 h | 6 h | Unlimited¹ | |
11 For other primers, refer to the "Interfine 979 Recommended Application Procedure" or Interspec for details.
Interfine 979 can be applied over a limited range of primers and intermediate coats.
Suitable primers:
| Intercure 200 | Interzinc 52 |
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| Intercure 200HS | Interzinc 52HS |
| Interplus 356 | Interzinc 315; Interzinc 22. Suitable intermediate coats: |
| Intercure 420 | Interzone 505 |
| Intergard 475HS | Interzone 954; Interseal 670HS. Interfine 979 must never be applied directly over Interzinc 52 cured with a low-temperature hardener. |
The maximum absolute interval for overcoating with Interfine 979 depends on the primer/intermediate coat. Before use, the Interfine 979 recommended application procedure must be consulted.
Interfine 979 is only suitable for self-overcoating.
| For further information on the industry standards, terms and abbreviations used in this datasheet, see www.international-pc.com | See the following documents on the website: • Definitions and Abbreviations • Surface Preparation • Paint Application • Theoretical and Practical Spreading Rates • Interfine 979 Application Guide. These sections are available as separate publications on request. |
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This product must be applied at the production site by professional applicators in accordance with the recommendations in this manual, the Material Safety Data Sheet and the instructions on the container label. Do not use this product without first reviewing the Material Safety Data Sheet (MSDS) that International Paint provides for its customers.
All work related to the application and use of this product must be carried out in accordance with the relevant national health, safety and environmental standards and regulations.
If welding or flame cutting is required on metal coated with this product, dust and fumes will be generated; use appropriate personal protective equipment and adequate local ventilation.
If in doubt about the suitability of this product for the intended use, consult AkzoNobel for further advice.
| Packaging Specifications | Component A | Component B | ||
| Volume | Packaging | Volume | Packaging | |
| 20 L | 16 L | 20 L | 4 L | 5 L |
| 5 US gal | 4 US gal | 5 US gal | 1 US gal | |
For other packaging sizes, contact AkzoNobel.
| Packaging Specifications | Component A | Component B |
| 20 L | 24.3 kg | 4.4 kg |
| 5 US gal | 49.6 lb | 8.8 lb |
| Shelf life | Component A: at least 12 months at 25 °C (77 °F). |
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Component B: at least 6 months at 25 °C (77 °F), inspect before use thereafter. Store in a dry, cool environment, away from heat sources and sources of ignition.
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Information is subject to the manufacturer's latest version; the manufacturer's latest TDS prevails.
The technical parameters on this page are taken from the product's original manufacturer technical datasheet, the copyright of which belongs to the manufacturer. If a rights holder considers the presentation inappropriate, contact us for verification and handling.
Packaging specifications and batch lead times are subject to actual availability. PleaseContact Uscontact us for project-based calculation.
