PPG SigmaCover 522 is a two-component, micaceous iron oxide-pigmented, polyamide-cured epoxy primer/sealer/coating. It has excellent adhesion to, and sealing of, weathered, cleaned, zinc-rich primers and metal-sprayed steel, with good adhesion to properly pre-treated galvanized steel.

Features & Benefits

• Two-component, micaceous iron oxide-pigmented, polyamide-cured epoxy primer/sealer/coating
• Can be used in systems for atmospheric or water-immersed exposure conditions
• Excellent adhesion to, and sealing of, weathered, cleaned, zinc-rich primers and metal-sprayed steel
• Good adhesion to properly pre-treated galvanized steel
• Good resistance to industrial or chemical-contaminated atmospheric exposure conditions
• Good abrasion and impact resistance
• Prevents Corrosion Under Insulation (CUI)
• Pass cryogenic cyclic test from -196°C (-321°F) to 140°C (284°F)
• Resistant to temperatures up to 200°C (390°F) in dry atmospheric exposure conditions
• No induction time
• 8 hours pot life
• Touch dry in 2 hours
• Fully cured after 7 days
• See below for more information on surface preparation, application details and curing times

Product Data

Two-component, micaceous iron oxide-pigmented, polyamide-cured epoxy primer/sealer/coating

Notes:

• See below for more information on surface preparation, application details and curing times

Surface Preparation

Recommended Substrate Conditions and Temperatures

Substrate conditions

• Steel;
• Blast cleaned to ISO-Sa2½, blasting profile 40 – 70 µm (1.6 – 2.8 mils)
• Shop primed steel;
• Sweep blasted to SPSS-Ss or power tool cleaned to SPSS-Pt3
• Zinc rich epoxies and zinc silicates must be dry and free from any contamination
• Galvanized steel;
• For atmospheric exposure conditions disc sanding, and for water immersed exposure conditions sweep blasting is required
• Stainless steel, non-ferrous metal should be sufficiently roughened by light sanding
• Compatible previous coat must be dry and free from any contamination
• When used as an adhesion primer or when a long overcoating interval is expected a maximum DFT of 50 µm (2.0 mils) must be specified in order to preserve the rough texture

Substrate Temperature & Application Conditions

• Substrate temperature during application and curing should be above 10°C (50°F)
• Ambient temperature during application at 5°C (41°F) is acceptable; however curing to hardness takes longer and complete cure will be reached when the temperature increases
• Substrate temperature during application and curing should be at least 3°C (5°F) above dew point

Application

Instructions for Use

Mixing ratio by volume: base to hardener 82:18

• The temperature of the mixed base and hardener should preferably be above 15°C (59°F), otherwise extra thinner may be required to obtain application viscosity
• Adding too much thinner results in reduced sag resistance
• Thinner should be added after mixing the components

Induction Time

None.

Pot life

• 8 hours at 20°C (68°F)

Refer below for more information

Air Spray

Recommended thinner

• THINNER 91-92

Volume of thinner

• 10 - 30%, depending on required thickness and application conditions

Nozzle orifice

• 1.5 – 2.0 mm (approx. 0.060 – 0.079 in)

Nozzle pressure

• 0.3 - 0.4 MPa (approx. 3 - 4 bar; 44 - 58 p.s.i.)

Airless spray

Recommended thinner

• THINNER 91-92

Volume of thinner

• 5 - 10%, 30 - 40% when mist coat applied

Nozzle orifice

• Approx. 0.48 – 0.53 mm (0.019 – 0.021 in)

Nozzle pressure

• 12.0 - 15.0 MPa (approx. 120 - 150 bar; 1741 - 2176 p.s.i.)

Brush/roller

Recommended thinner

• THINNER 91-92

Volume of thinner

• 0 – 5%

Spreading Rate and Film Thickness

Overcoating interval for DFT up to 50 µm (2.0 mils)

Overcoating interval for DFT up to 100 µm (4.0 mils)

Notes:

• Surface should be dry and free from any contamination
• The minimum overcoating time should be multiplied by 5 when SIGMACOVER 522 is to be applied on top of an existing old (alkyd) primer or coating
• Surface should be properly cleaned
• Glossy finishes require a corresponding undercoat

Curing time for DFT up to 100 μm (4.0 mils)

Notes:

• Adequate ventilation must be maintained during application and curing (please refer to information sheets 1433 and (1434)
• For optimum resistance in tank coating systems a minimum substrate temperature of 10°C (50°F) is essential

Pot Life (at application viscosity)

Safety Precautions

• For paint and recommended thinners, see information sheets information sheet 1430, information sheet 1431 and the relevant Material Safety Data Sheets in the attachments section above
• This is a solvent-borne paint and care should be taken to avoid inhalation of spray mist or vapor, as well as contact between the wet paint and exposed skin or eyes

References

• Conversion Tables (information sheet 1410)
• Explanation to product data sheets (information sheet 1411)
• Safety Indicators (information sheet 1430)
• Safety in Confined Space and Health Safety, Explosion Hazard - Toxic Hazard (information sheet 1431)
• Safe Working in Confined Spaces (information sheet 1433)
• Directives for Ventilation Practice (information sheet 1434)
• Cleaning of Steel and Removal of Rust (information sheet 1490)
• Specification for Mineral Abrasives (information sheet 1491)
• Relative humidity - Substrate Temperature - Air Temperature (information sheet 1650)