Graco 311511G Moisture Sensitivity of Isocyanates, Foam Self-Ignition, Isocyanate Hazard

Moisture Sensitivity of Isocyanates

Isocyanates (ISO) are catalysts used in two component foam and polyurea coatings. ISO will react with moisture (such as humidity) to form small, hard, abrasive crystals, which become suspended in the fluid. Eventually a film will form on the surface and the ISO will begin to gel, increasing in viscosity. If used, this partially cured ISO will reduce performance and the life of all wetted parts.

The amount of film formation and rate of crystallization varies depending on the blend of ISO, the humidity, and the temperature.

To prevent exposing ISO to moisture:

•Always use a sealed container with a desiccant dryer in the vent, or a nitrogen atmosphere. Never store ISO in an open container.

•Keep the Iso (A) Pump Lube system jar 3/4 filled with clean Throat Seal Lubricant (TSL) 206995. Change whenever fluid appears cloudy.

•Use moisture-proof hoses specifically designed for ISO, such as those supplied with your system.

•Never use reclaimed solvents, which may contain moisture. Always keep solvent containers closed when not in use.

•Never use solvent on one side if it has been contaminated from the other side.

•Always park pumps when you shutdown.

•Always lubricate threaded parts with Part 217374 ISO pump oil or grease when reassembling.

Foam Self-Ignition

Some materials may become self-igniting if applied too thick. Read material manufacturer’s warnings and material MSDS.

Moisture Sensitivity of Isocyanates

Isocyanate Hazard

Spraying materials containing isocyanates creates potentially harmful mists, vapors, and atomized par- ticulates.

Read material manufacturer’s warnings and material MSDS to know specific hazards and precautions related to isocyanates.

Prevent inhalation of isocyanate mists, vapors, and atomized particulates by providing sufficient ventila- tion in the work area. If sufficient ventilation is not available, a supplied-air respirator is required for everyone in the work area.

To prevent contact with isocyanates, appropriate per- sonal protective equipment, including chemically impermeable gloves, boots, aprons, and goggles, is also required for everyone in the work area.

Keep Components A and B Separate

NOTICE

To prevent cross-contamination of the equipment’s wetted parts, never interchange component A (isocyanate) and component B (resin) parts.

Changing Materials

•When changing materials, flush the equipment multiple times to ensure it is thoroughly clean.

•Always clean the fluid inlet strainers after flushing.

•Check with your material manufacturer for chemical compatibility.

•Most materials use ISO on the A side, but some use ISO on the B side.

•Epoxies often have amines on the B (hardener) side. Polyureas often have amines on the B (resin) side.