PPG SigmaCover 690 – Aluminium-Pigmented High-Solids Epoxy Coating

PPG SigmaCover 690 is a two-component, high-solids, aluminium-pigmented epoxy primer/coating designed for maintenance and refurbishment of steel structures. Its self-priming formulation offers strong adhesion even on lower grades of surface preparation, making it ideal for repair work and overcoating aged but sound coatings.

Engineered for durability, SigmaCover 690 provides excellent impact and abrasion resistance, along with a tough protective barrier suitable for demanding industrial environments. It cures at temperatures down to 5°C (41°F) with low VOC, and can be overcoated with both epoxy and polyurethane finishes. For colder conditions, the winter-grade version should be used.

Key Features:

• Two-component, aluminium-pigmented high-solids epoxy

• Self-priming and surface-tolerant for maintenance applications

• Compatible with most aged, well-adhered coatings

• Can be recoated with epoxy and polyurethane systems

• Excellent impact and abrasion resistance

• Cures down to 5°C (41°F); winter-grade available for 0°C conditions

• No induction time – 3-hour pot life

• Touch dry in 4 hours; fully cured in 5 days

Surface Preparation

Atmospheric exposure conditions
• Steel; blast cleaned to ISO-Sa2 or power tool cleaned to ISO-St2 for good corrosion protection
• Steel with approved shop primer; sweep blasted to SPSS-Ss or power tool cleaned to SPSS-Pt2
• Existing sound coating systems; sufficiently roughened, dry and cleaned
Immersion in water
• Steel; blast cleaned to ISO-Sa2½
• Steel with approved zinc silicate shop primer; sweep blasted to SPSS-Ss or power tool cleaned to SPSS-Pt3
Substrate temperature
• Substrate temperature during application and curing should be above 5°C (41°F)
• Substrate temperature during application and curing should be at least 3°C (5°F) above dew point

Technical Data

Spreading rate and film thickness
DFT Theoretical spreading rate
75 µm (3.0 mils) 12.0 m²/l (481 ft²/US gal)
100 µm (4.0 mils) 9.0 m²/l (361 ft²/US gal)
125 µm (5.0 mils) 7.2 m²/l (289 ft²/US gal)

Directions for Use

Mixing ratio by volume: base to hardener 77.5:22:5
• 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 and slower cure
• Thinner should be added after mixing the components

Air spray
Recommended thinner
THINNER 91-92
Volume of thinner
5 - 10%, depending on required thickness and application conditions
Nozzle orifice
1.8 – 2.0 mm (approx. 0.070 – 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
0 - 5%, depending on required thickness and application conditions
Nozzle orifice
Approx. 0.48 – 0.53 mm (0.019 – 0.021 in)
Nozzle pressure
15.0 MPa (approx. 150 bar; 2176 p.s.i.)

Brush/roller
Recommended thinner
THINNER 91-92
Volume of thinner
0 – 5%

Cleaning solvent
THINNER 90-53

Data Sheets

SigmaCover 690 TDS

SigmaCover 690 Base MSDS

SigmaCover 690 Activator MSDS