PPG SigmaFast 302 is a two-component, silicate zinc epoxy primer for steel, with good anticorrosive properties and quick drying times, at temperatures as low as -5°C (23°F).

Features & Benefits

• Good anticorrosive properties
• Fast-curing
• Fast-handling
• Cures at temperatures down to -5°C (23°F)
• Reduced risk of mud cracking
• Topcoats must be unsaponifiable
• See below for more information on surface preparation, application details and curing times

Product Data

Two-component, silicate zinc epoxy primer

Notes:

• Refer below for more details on spreading rate and film thickness, overcoating intervals 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)

Substrate Temperature & Application Conditions

• Substrate temperature during application and curing down to -5°C (23°F) is acceptable; provided the substrate is free from ice and dry
• 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 80:20 (4:1)

• 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

Pot Life

• 4 hours at 20°C (68°F)

Air Spray

Recommended thinner

• THINNER 21-06

Volume of thinner

• 15 - 20%, depending on required thickness and application conditions

Nozzle orifice

• 1.6 mm (approx. 0.063 in)

Nozzle pressure

• 0.3 - 0.6 MPa (approx. 3 - 6 bar; 44 - 87 p.s.i.)

Airless Spray

Recommended thinner

• THINNER 21-06

Volume of thinner

• 5 - 15%, depending on required thickness and application conditions

Nozzle orifice

• Approx. 0.38 – 0.53 mm (0.015 – 0.021 in)

Nozzle pressure

• 15.0 MPa (approx. 150 bar; 2176 p.s.i.)

Brush/roller

Recommended thinner

• THINNER 21-06

Volume of thinner

• 0 – 5%

Cleaning Solvent

• Thinner 90-53

Spreading Rate and Film Thickness

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

Overcoating interval for DFT up to 80 µm (3.1 mils)

Notes:

• Surface should be dry and free from any contamination
• An interval of several months can be allowed under clean interior exposure conditions
• Before overcoating any visible surface contamination must be removed by sandwashing, sweep blasting or mechanical cleaning

Curing time for DFT up to 80 µm (3.1 mils)

Note:

• Adequate ventilation must be maintained during application and curing

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)