Intergard 251 Epoxy Zinc Phosphate Primer is an epoxy coating used as a primer. As a primer for new construction or industrial maintenance, used on suitably prepared surfaces, widely used in offshore facilities, petrochemical plants, chemical plants, paper mills and the bridge industry. A two-component epoxy zinc phosphate anticorrosive primer. A 75 µm (3 mil) dry film can normally be overcoated after 6–12 months of exposure (depending on the corrosivity of the environment), subject to suitable cleaning and repair of any damaged areas. Parameters on this page: volume solids 63% ± 2%, dry film thickness 50–75 µm (2–3 mil), theoretical spreading rate 8.40 m²/L.
Source: AkzoNobel original technical data sheet (TDS) "Intergard 251 Epoxy Zinc Phosphate Primer"; spreading rate and other values are converted from TDS parameters and are 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 | 63% ± 2% |
|---|---|
| Dry Film Thickness | 50–75 µm (2–3 mils) |
| Theoretical Spreading Rate | 8.40 m²/L |
| VOC | 3.25 lb/gal (390 g/L) US EPA Method 24 293… |
| Density / Specific Gravity | 1.38 kg/L (11.5 lb/gal) |
| Number of Components | Two-component |
| Thinner | Do not thin beyond the limits of local regulations |
| Mixing Ratio | 4 parts : 1 part (by volume) |
| Colour / Appearance | Pale yellow, grey, iron oxide red, INTERGARD 251 |
For more Q&A on selection, application, acceptance and defect diagnosis, seeFAQsection.
A two-component epoxy zinc phosphate anticorrosive primer.
Used as a primer for new construction or industrial maintenance on suitably prepared surfaces, widely used for offshore installations, petrochemical plants, chemical plants, paper mills and bridges.
The fast drying and handling characteristics, together with long-term recoatability, allow this primer to be applied in the factory before the full system is applied on site. Intergard 251 has good abrasion resistance, reducing mechanical damage during transport between factory and site.
| Colour | Pale yellow, grey, iron oxide red, INTERGARD 251 |
|---|---|
| Gloss | Matt |
| Volume Solids | 63% ± 2% |
| Typical thickness | Dry film 50–75 µm (2–3 mils), equivalent to wet film 79–119 µm (3.2–4.8 mils) |
| Theoretical Spreading Rate | At 75 µm dry film thickness and the stated volume solids: 8.40 m²/L; at 3 mils dry film thickness and the stated volume solids: 337 ft²/US gal |
| Practical Spreading Rate | Allowing for a suitable loss factor |
| Application Methods | Air spray, airless spray, brush, roller. Drying time: recommended topcoat recoat interval |
| Temperature | Surface Dry | Hard Dry | Minimum | Maximum |
| 10°C (50°F) | 2 h | 7 h | 12 months¹ | |
| 15°C (59°F) | 1 h | 5 h | 12 months¹ | |
| 25°C (77°F) | 45 min | 3 h | 12 months¹ | |
| 40°C (104°F) | 30 min | 2 h | 12 months¹ | |
¹ When polysiloxane topcoats are used, the maximum recoat interval is reduced. For details, consult International Paint.
| Flash point (typical) | Component A 24 °C (75 °F); Component B 27 °C (81 °F); mixed 24 °C (75 °F) |
|---|---|
| Product weight | 1.38 kg/L (11.5 lb/gal) |
| Volatile Organic Compounds | 3.25 lb/gal (390 g/L) US EPA Method 24. 293 g/kg. EU Solvent Emissions Directive (EU Council Directive 2010/75/EU). Coating hazards: GB 30981.2-S-Pb≤1000-NC. Complies with GB 30981.2-2025. For further 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.
Oil and grease must be removed in accordance with the SSPC-SP1 solvent cleaning standard.
Blast cleaning: blast steel surfaces to Sa 2½ (ISO 8501-1:2007) or SSPC-SP6. If oxidation occurs between blasting and application of Intergard 251, re-blast to the specified visual standard.
Surface defects exposed by blast cleaning must be ground, filled or treated by a suitable method.
The surface profile shall be at least 50 µm (2 mil).
Shop-primed steel: welds and damaged areas require preparation to at least St3 (ISO 8501-1:2007) or SSPC-SP3. Blasting to Sa 2½ (ISO 8501-1:2007) or SSPC-SP6 gives ideal performance. If this requirement cannot be met, power-tool preparation to SSPC-SP11 is recommended.
If the shop primer shows large-area or widespread scattered damage, full brush-off blasting may be required.
| 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) |
|---|
| Pot life | 10°C (50°F) | 15°C (59°F) | 25°C (77°F) | 40°C (104°F) |
| 10 h | 8 h | 6 h | 3 h |
| Suitable for airless spray | Recommended nozzle tip size 0.38–0.53 mm (15–21 thou); total paint pressure at the nozzle not less than 155 kg/cm² (2204 psi) |
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| Air Spray | Recommended | Spray gun | DeVilbiss MBC or JGA |
| Air nozzle | 704 or 765 | ||
| (with pressure pot) | Nozzle | E | |
| Brush | Suitable | Typical thickness 40–50 µm (1.6–2.0 mils) | |
| Roller application | Suitable | Typical thickness 40–50 µm (1.6–2.0 mils) | |
| Thinner | International GTA220 | Do not thin beyond the limits of local regulations. |
(or International GTA415)
| Cleaner | International GTA822 or International GTA415 |
|---|---|
| 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 resealed. If work is interrupted for too long, mix a fresh batch of paint for application.
| 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 interruptions, and other factors. |
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Surplus paint and empty containers must be disposed of in accordance with the relevant regional regulations.
Intergard 251 should be used with certain products in certain chemical environments, because zinc-containing coatings are attacked by acids and alkalis in such chemical environments.
The maximum overcoating interval depends on the integrity of the exposed film. A 75 µm (3 mil) dry film can usually be overcoated after 6–12 months of exposure (depending on the corrosivity of the environment), after suitable cleaning and repair of any damaged areas.
Avoid excessive film thickness, since the adhesion of a topcoat over an aged thick film is not as good as over a film at the specified thickness. When used as a holding primer, avoid excessive film thickness, since intercoat adhesion problems can arise if the subsequent coat is also applied too thickly.
Over-thick application of Intergard 251 extends the minimum recoat and handling times, adversely affecting long-term recoatability.
When applying Intergard 251 by brush or roller, multiple coats are necessary to achieve the specified total system dry film thickness.
This product does not cure adequately below 5 °C (41 °F). For ideal performance, the curing temperature should be above 10 °C (50 °F).
The temperature of the surface to be coated must be at least 3 °C (5 °F) above the dew point.
As with all epoxy coatings, Intergard 251 chalks and fades on exposure to the atmosphere. This does not affect anti-corrosion performance.
Intergard 251 is not designed for continuous immersion in water.
For durable decorative surfaces requiring good gloss and colour retention, overcoat with the recommended topcoat.
After consulting the International Paint Protective Coatings division, this paint may be applied by other methods such as flow coating.
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.
Intergard 251 is designed for application on suitably prepared steel, and may also be applied over approved pre-construction primers. Details are available from International Paint.
The following primers may be used with Intergard 251: Interzinc 22 *(a mist coat or tie coat may be required), Interzinc 52, Interzinc 2280 *(a mist coat or tie coat may be required), InterH2O 280. The following topcoats are recommended for use with Intergard 251:
| Intercure 200HS | Intergard 475HS |
|---|---|
| Intercure 420 | Intergard 740 |
| Interfine 629HS | Interseal 670HS |
| Interfine 878 | Interthane 870 |
| Interfine 979 | Interthane 990 |
| Intergard 251 | Interthane 990E, Intergard 345. Other topcoats are also available; consult International Paint. |
For details, see the relevant product data sheet
| For further information on the industry standards, terms and abbreviations used in this datasheet, see www.international-pc.com | In the following documents on the website: • Definitions and abbreviations • Surface preparation • Coating application • Theoretical and practical spreading rate. These sections are also 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 | 26 kg | 4.2 kg |
| 5 US gal | 54.2 lb | 8.8 lb |
| Shelf life | At least 12 months at 25 °C (77 °F). |
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Thereafter, inspection is required. Store in a dry, cool environment away from heat 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.
The in-plant item numbers of Intergard 251 Epoxy Zinc Phosphate Primer are as follows.Item No.is the most accurate form when ordering;Colour/colour codecorresponds to the actual colour (RAL, GSB are colour chart codes);Packaging SpecificationsFactory complete-set specification format. Colors not listed may be ordered against the colour card.
| Item No. | Colour / colour code | Packaging Specifications |
|---|---|---|
| KGA905 | Grey | 20 L |
| KGA902 | Red | 20 L |
This model has a total of2item numbers, all listed on this page; colours outside the table (including special colours and bulk packaging) can be confirmed by phone, delivery dates are advised according to the factory's current production schedule and stock. In the packaging specification, the "+" indicates the complete-set notation for two-component products (base + curing agent), subject to the factory specification; a "—" in the colour column denotes an auxiliary product, or that the item has no colour code in the factory system.
