PPG SigmaDur 1800 – High-Solids Polyurethane Finish with Superior UV Resistance

PPG SigmaDur 1800 is a two-component, high-solids polymeric urethane finish designed for long-term protection in heavy-duty atmospheric conditions. Engineered for exceptional colour and gloss retention, it delivers a non-yellowing, non-chalking finish that withstands harsh environments, making it ideal for industrial, marine, offshore, and structural steel applications.

This durable coating cures in low temperatures down to –5°C (23°F) and can be recoated even after extended weathering, offering flexibility for maintenance cycles and large-scale projects. It is available in thousands of colours including RAL, BS, NCS, and the latest NCS 2050 series, providing wide specification freedom.

SigmaDur 1800 also exhibits strong resistance to abrasion, weathering, mineral and vegetable oils, paraffins, aliphatic hydrocarbons, and mild chemicals, ensuring long-lasting protective performance.

Key Features:

• Two-component, high-solids polyurethane finish

• Outstanding colour & gloss retention; non-chalking and non-yellowing

• Cures down to –5°C (23°F)

• Excellent resistance to weathering and abrasion

• Chemical resistance to oils, paraffins, aliphatic petroleum products & mild chemicals

• Recoatable after long atmospheric exposure

• Available in RAL, BS & NCS Colours

• Ideal for marine, industrial & structural steel environments

Surface preparation

Substrate conditions
• Previous coat (epoxy or polyurethane) must be dry and free from any contamination
• Surface of previous coat should be sufficiently roughened if necessary
Substrate temperature and application conditions
• Substrate temperature during application and curing should be at least 3°C (5°F) above dew point
• Relative humidity during application and curing should not exceed 85%

Technical Data

Pot life
5 hours at 20°C (68°F)
Note:
- See ADDITIONAL DATA – Pot life

Spreading rate and film thickness
DFT Theoretical spreading rate
50 µm (2.0 mils) 13.6 m²/l (545 ft²/US gal)
60 µm (2.4 mils) 11.3 m²/l (454 ft²/US gal)
75 µm (3.0 mils) 9.1 m²/l (364 ft²/US gal)

Directions for Use

Mixing ratio by volume: base to hardener 5:1
• 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
• Thinner should be added after mixing the components
• Adding too much thinner results in reduced sag resistance

Air spray
Recommended thinner
THINNER 21-06
Volume of thinner
5 - 10%, depending on required thickness and application conditions
Nozzle orifice
1.0 - 1.5 mm (approx. 0.040 - 0.060 in)
Nozzle pressure
0.3 - 0.4 MPa (approx. 3 - 4 bar; 44 - 58 p.s.i.)

Airless spray
Recommended thinner
THINNER 21-06
Volume of thinner
3 - 5%, depending on required thickness and application conditions
Nozzle orifice
Approx. 0.38 – 0.43 mm (0.015 – 0.017 in)
Nozzle pressure
18.0 MPa (approx. 180 bar; 2611 p.s.i.)

Brush/roller
Recommended thinner
THINNER 21-06
Volume of thinner
0 – 5%

Cleaning solvent
• THINNER 90-53

Data Sheets

SigmaDur 1800 TDS

SigmaDur 1800 Base MSDS

SigmaDur 1800 Hardener MSDS