Preparation
The substrate must be a minimum of 14 days old, have a minimum compressive strength of 25 N/mm² and a minimum pull-off strength of 1.5 N/mm².
The surface must be free of brittle particles and laitance. Any remains of previous coatings should be removed by means of scabbling, shotblasting and/or diamond grinding or steam cleaning.
Important: closed pores must be exposed to ensure good adhesion to the surface.
All water must be removed from the surface, leaving it damp but not wet. DPM Primer XFH may then be applied to the damp surface immediately after cleaning.
Mixing
Mix only as much as can be applied within the pot life (see ‘Pot Life and Curing Time’). Add part ‘A’ to part ‘B’ in a suitable container, and thoroughly mix for at least 3 minutes. For best results use a slow speed drill with a mixing paddle, making sure all material from the sides and bottom of the container are thoroughly mixed in and a homogeneous mix is obtained.
Thorough mixing is imperative as an unmixed product will result in a poor or non-cure situation.
Application
Apply by brush, short to medium pile lamb wool roller, or squeegee, in one or more continuous applications until the material is absorbed and a film has formed. Make certain that the entire surface is completely covered to prevent oil or water migration. Oil or grease impregnated surfaces should be primed using a paintbrush or soft sweeping broom to work the material well into the surface.
Under no circumstances should aggregate be added to the first coat as this will allow water to bleed through the primer and contaminate the following coats.
If the period between the application of the primer and relevant top coat exceeds 24 hours, then a second coat of primer must be applied with fine kiln-dried aggregate sprinkled evenly over the wet second coat at a rate of 1kg per m² to provide a key for the final coating. Spiked shoes should be worn to avoid disturbing the wet coating. Allow to cure for a further 24 hours before removing all loose aggregate from the surface, which is then ready to receive a suitable top coating (Flortex EP/Flortex Professional/Flortex Chemical Coat).
If time is very limited – the following method may be used, but this is not advisable for very damp or heavily contaminated substrates: The first coat of DPM Primer XFH may be overcoated within 4-12 hours with an appropriate top coat. To ensure chemical bonding between DPM Primer XFH and the over-coating this interval should not exceed 12 hours. Allow to cure and recoat if required: see appropriate coating Data Sheet.
Application Conditions
The ideal ambient temperature of the substrate and work area should be a minimum of 15°C during the application and curing period. Curing time will be extended at lower temperatures. Important: Ambient and substrate temperatures must not fall below 10˚C during the application or curing process as this causes an irreversible reaction blockade.
