PPG - Sigmadur 520 - Polyurethane Finish is a two component high build semi gloss aliphatic acrylic polyurethane finish.

Features

• Easy application by roller and airless spray
• Unlimited recoatable
• Excellent resistance to atmospheric exposure conditions
• Good color and gloss retention (aluminum version becomes grey)
• Cures at temperatures down to -5°C (23°F)
• Tough and abrasion resistant
• Resistant to splash of mineral and vegetable oils, paraffins, aliphatic petroleum products and mild chemicals
• Can be recoated even after long atmospheric exposure

Recommended Substrate Conditions and Temperatures

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 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
• Relative humidity during application and curing should not exceed 85%
• Premature exposure to early condensation and rain my cause color and gloss change

Instructions For Use

Mixing ratio by volume: base to hardener 88:12

• The temperature of the mixed base and hardener should be above 10°C (50°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
• Aluminum version has lower gloss than the standard version and the color could be different by application method

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

0 - 5%, depending on required thickness and application conditions

Nozzle orifice

Approx. 0.46 mm (0.018 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