Pragokor Metal SP is a two-component solvent-based zincethylsilicate preconstruction primer, in a grey colour, which is to be applied in thinner dry film thicknesses (max. 40 µm). It should be particularly applied, just after blasting process, for inter-operation protection of steel sections and sheets for the period of their storage, transport and handling before the assembly of the structure. Blasting with both grit and shot abrasives is possible under the shop primer.
The paint for application should be prepared by a thorough mixing of both liquid and powder components.
- Inorganic shop primer with metallic zinc content as the anticorrosion pigment of very high performance.
- Temperature durability up to 400°C, very good resistance to abrupt temperature changes.
- Protection efficiency at 20 µm of dry film thickness for at least 12 months.
- After complete curing, very high hardness and durability against wear are achieved.
- It is able to protect, in a way, the steel substrate electrochemically (cathodically) in minor paint imperfections and shows an increased protection performance against paint undercutting.
- Complete resistance against UV radiation (sun radiation).
The paint, applied on steel sections or sheets in thickness 15 – 20 µm just after their blasting, is of a very high protection performance and, moreover, will enable their subsequent welding and flame cutting without an inferior welds quality. . In this case, Pragokor Metal SP cannot fully replace the function of the permanent primer which should be applied over the preconstruction primer in the shop or after the assembly of the structure. Suitable primers over Pragokor Metal SP are either organic zinc-rich paints or modified inorganic zincsilicate types Pragokor Metal E or Pragokor Metal ESG which, unlike the unmodified zincsilicates, do not at first require a roughening of the Pragokor Metal SP coating by sweep blasting.
As a permanent primer, it should be used in the dry film thickness 40 µm in the combination with organic topcoats, e.g. epoxides, coal-tar epoxides, vinyl, polyurethanes, chlorine-rubbers, silicones, acrylates, silicone-acrylates and water-based styrene-acrylate copolymers.
Thinning: Pragokor Thinner Z (max. 15 % by vol.).
Theoretical spreading rate at the dry film thickness 20 µm: 17,5 m2/litre.
Pot-life after mixing of both components: min. 12 hours (at 20 °C).
Drying time to touch: about 5 minutes (20 µm thickness, 20 °C).
Curing time for topcoating (20 µm of dry film thickness, temperature 20 °C and 75 % relative humidity): about 3 days (enhanced both relative humidity and temperature will accelerate curing process).