Isopropyl alcohol (isopropanol)
Isopropyl alcohol is the go-to wipe solvent of the coatings world and a useful co-solvent, but its hydroxyl group makes it an enemy of anything containing isocyanate.
IPA is a three-carbon secondary alcohol (molecular weight 60.10 g/mol). It is a clear, colorless liquid with a characteristic odor, a boiling point of 82.5 °C and a flash point of about 12 °C. It is fully miscible with water and most organic solvents.
IPA is highly flammable, causes serious eye irritation and may cause drowsiness or dizziness. ACGIH recommends a TLV-TWA of 200 ppm. Use with ventilation, keep away from ignition sources, bond and ground containers, and dispose of solvent-soaked rags safely.
Not in the material. Its hydroxyl group reacts with isocyanate. For surface wiping, allow it to evaporate completely before coating, and use the cleaning solvents the manufacturer specifies for spray equipment.
99%. The 70% grade contains 30% water, which can leave residue or moisture on the surface before coating.
Solvent cleaning removes light contaminants but does not create a surface profile. It is usually one step before abrasive blasting or mechanical preparation, as described in SSPC-SP 1.
