Astro (HBP) High Build Primer

Tax included.
Key Features
  • Protects intumescent paint.
  • Assists in the control of flame-spread.
  • Provides a decorative rust-inhibiting decorative finish.
  • Primes cleaned steel prior to overcoating.
  • Suitable for use direct to bare, intumescent painted or sound previously painted structural steel and cast iron.

Product Description

A High Build Quick Drying corrosion resistant metal primer for structural steel and cast iron. Compatible with Astroflame ISS Paint systems.

Suitable for application in Steel Fabricator's shops or on site. Will protect exposed structural steel during construction as well as protecting internal steelwork thereafter.

Finish, Colour Ranges & Availability
Astroflame HBP Primer is available in a Metallic and Mid-grey range. 2.5 litre and 5 litre containers.

Fire Rating
Use in conjunction with Astro ISS Paint systems for 30, 60, 90, 120 mins
Class 0 on non-combustible or intumescent protected surfaces
For certification and compliance with regulations the manufacturer will supply a Certificate of Supply on request.

To Specify
To decorate & protect bare or painted internal steel apply 2 coats Astro HBP Primer
To bare steel or cast iron apply 2 coats Astro HBP Primer.


Flame retardant agents
Water-resistant binders
High opacity, corrosion and flash-rust resistant pigments

8 sq m per litre per coat

Brush, roller, conventional and airless spray
Ensure surfaces are clean, dry and sound
Minimum application temperature 6°C
Do not apply when condensation may form

New Steel - blast clean to SA 2.5 and prime immediately
Other steel or cast iron – degrease, remove all rust & mill-scale
Thoroughly abrade old gloss or eggshell
Galvanised steel – treat with T Wash / Mordant Solution before application
Not suitable for stainless steel

Minimum Drying Times
Touch Dry 2 hours
Hard dry 4 hours
Re-coat 4 hours
Note – drying times affected by temperature & humidity

Compatible Overcoats
When used as a primer, it can be over-coated with water-based or white spirit based paints

All interested parties, designer, specifier, main contractor and specialist installers should provide access to allow the fire stopping seals to be regularly inspected and maintained, as well as records kept of such maintenance at minimum periods of 12 months, as required by the Regulatory Reform Order, and repaired if necessary. Reference should be made to ASFP TGD 17 – Code of Practice for the Installation and Inspection of Fire Stopping.

It is vital that those entrusted to design or install a fire stopping product have the necessary levels of competence to undertake the task professionally and thoroughly. The level of competency required will be commensurate with the expected complexity of the building. All designers must eliminate, reduce or control foreseeable risks that may arise during installation, construction or maintenance when preparing or modifying designs. Clients should ensure that the principal designer and principal contractor carry out their duties under CDM regulations. The ASFP foundation course in passive fire protection provides essential knowledge as part of demonstrating competency and understanding in this key fire protection specialism.