Hempaprime Ultimate 850

Product characteristics

Recommended use
Hempaprime Ultimate 850 is recommended as a general purpose, heavy-duty, rust-preventing primer for newbuild and maintenance. Suitable for structural steel and piping. Recommended for a wide range of atmospheric corrosivity environments up to extreme (offshore). The product can be used as a single, complete coating for long-term protection of steel exposed to moderately to severely corrosive environment and abrasion. Also suitable for select tank lining applications in accordance with Hempel’s specification. For further information contact your local Hempel representative.

Service temperature:

• Without topcoat: maximum, dry, atmospheric exposure: 450°C [842°F].
• With a suitable topcoat: maximum, dry, atmospheric exposure: 540°C [1004°F], peak: 600°C [1112°F].
• Other liquids: Please contact Hempel.

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Certificates / Approvals

• Meets requirements to ISO 12944 when used as part of a predefined paint system. Part 6 C5. Part 9CX.
• Meets requirements to NORSOK M-501 when used as part of a predefined paint system. Edition 6, System 1. Edition 7, System 1A.
• Compliant with requirements for use in Slip-B construction joints. Contact Hempel for relevant test report.

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Features

• High volume solids.
• Low VOC.
• Fast curing.

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Product safety

Flash point
20°C [68°F]

VOC content mixed product

Legislation	Value
EU	418 g/L [3.49 lb/US gal]
US (coatings)	418 g/L [3.49 lb/US gal]
US (regulatory)	418 g/L [3.49 lb/US gal]
China	418 g/L [3.49 lb/US gal]

According to specific legislation, see details in the Explanatory Notes available at Hempel website, hempel.com or at your local Hempel website. According to EPA Method 24.

Handling
Handle with care. Before and during use, observe safety labels on packaging and paint containers and follow all local and national safety regulations. Always consult Hempel’s Safety Data Sheet for this product along with the Product Data Sheet.
For professional use only.

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Product data

• Product code: 15711
• Product components: Base 15718, Zinc 97170
• Standard shade / code: Grey 19840
• Gloss: Flat
• Volume solids: 70 ± 2%
• Specific gravity: 2.6 kg/L [22 lb/US gal]
• Reference dry film thickness: 50 micron [2.0 mils]

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Surface preparation

Cleanliness

• Remove oil, grease and other contaminants by suitable detergent cleaning.
• Remove salts, detergents and other contaminants by high pressure fresh water cleaning.

New build:

• Abrasive blasting to min. Sa 2½ (ISO 8501-1) / SP 10 (SSPC).
• Remove dust, blast media and loose materials.

Maintenance and Repair

• According to Hempel’s Specification.

Roughness

• Surface profile Medium (G) (ISO 8503-2).
  Consult Hempel’s separate Surface Preparation Guidelines for more details.

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Application

Mixing ratio
Base 15718 : Zinc 97170 (32 : 68 by weight)

Products containing floating or settling particles/pigments need to be continuously stirred during application. This is especially important in case of heavy thinning.

Thinner

• Hempel’s Thinner 08700
• Hempel’s Accelerator & Thinner 0870M

Cleaner

• Hempel’s Thinner 08700

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Pot life

Product temperature	Pot life
10°C [50°F]	8 hours
20°C [68°F]	4 hours
30°C [86°F]	3 hours

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Application method

Tool	Application parameters
Airless spray	Nozzle pressure: 100 bar [1500 psi], Nozzle orifice: 0.019-0.023″
Air spray	Not Applicable
Brush	Not Applicable

To minimise dry spray at high temperatures, extra thinning may be necessary. If brush or roller application is used, more coats will be necessary to achieve the specified dry film thickness. Spray data are indicative and subject to adjustment. Pressure is for a material temperature of 20°C [68°F].

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Film thickness

Specification range	Dry film thickness	Wet film thickness	Theoretical spreading rate
Low	50 micron [2.0 mils]	71 micron [2.9 mils]	14 m²/L [570 sq ft/US gal]
High	100 micron [4.0 mils]	143 micron [5.7 mils]	7 m²/L [285 sq ft/US gal]
Recommended	50 micron [2.0 mils]	71 micron [2.9 mils]	14 m²/L [570 sq ft/US gal]

Overthickness must be closely controlled and never locally exceed 125 micron [5.0 mils] DFT. On irregular surfaces it is recommended to employ special care in avoiding over application.

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Application conditions

• To avoid condensation, apply on a clean and dry surface with a temperature that is at least 3°C [5°F] above the dew point.

Relative Humidity:

• Relative humidity must be above 50% during curing.

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Application remarks

• Consult Hempel’s Application Guidelines and Instructions for more details.

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Drying and overcoating

Product compatibility

• Previous coat: None.
• Subsequent coat: None or according to Hempel’s specification.

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Drying time

Surface temperature	Touch dry (min)	Hard dry (min)	Fully cured (hours)
10°C [50°F]	30	120	12
20°C [68°F]	15	60	6
30°C [86°F]	7¼	30	4

Determined for dry film thickness 50 micron [2.0 mils] at standard conditions, see Hempel’s Explanatory Notes for details. The drying times of moisture curing products will depend on the relative humidity, therefore drying times in the field could vary.

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Overcoating

• Consult Hempel’s specification for more information.

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Drying conditions

• To obtain the drying time stated, it is important to maintain sufficient ventilation during application, drying and curing.
• According to Hempel’s Specification.

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Overcoating details

• Remove zinc salts or other contamination before overcoating.
• Flash-coat technique is recommended when overcoating Galvosil qualities.
• The surface must be dry and clean prior to application.

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Storage

Shelf life

Ambient temperature	Base	Zinc
25°C [77°F]	6 months	36 months

Shelf life from date of production, when stored in original, unopened containers. Thereafter, the product quality must be re-inspected. Storage at elevated temperatures may reduce shelf life. For advice, please consult Hempel.

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Storage conditions

• Product must be stored according to local legislation, at maximum 40°C [104°F], without direct sunlight and protected from rain and snow.

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Carbon Footprint

Dry film thickness	GWP (Global Warming Potential)
1 µm	18.8 g CO₂e/m²
1 mil	0.098 lb CO₂e/ft²

The carbon footprint is for 1 square meter / square foot of surface area with a dry film thickness of 1 micron / mil.
The scope includes raw materials, in-bound transport to the Hempel factory, Hempel manufacturing processes, and any Volatile Organic Compounds emitted during and after the application of the product.
It is calculated based on the standard shade defined in this PDS. Values may vary with shade.

References

Product Data Sheet –Hempaprime Ultimate 850
Issued by Hempel A/S – October 2024
Document Version: 4/4
Source: https://www.hempel.com

Technical Guidelines and Explanatory Notes
Last accessed: 28 May 2025
Reference link: https://www.hempel.com/service-and-support/technical-guidelines

Note: Always consult the latest version of the Product Data Sheet and associated documents directly from Hempel’s official website to ensure accuracy and compliance with the most current recommendations.