ISO 12944 C1 Interior Dry Coating System

Environment Definition

ISO 12944 C1 is a very low atmospheric corrosivity class. It is normally associated with heated, dry interior spaces where steel is not exposed to condensation, salt, chemical fumes, or persistent humidity.

Typical examples include offices, schools, dry storage rooms, residential interiors, and protected indoor steel components.

Coating Selection Logic

C1 projects usually do not need a heavy anti-corrosion system. The main selection questions are appearance, handling damage, indoor humidity, cleaning process, and whether the steel already has a shop primer or old coating.

For simple indoor steel, a light-duty anti-rust primer and compatible alkyd, acrylic, or decorative topcoat is often enough. If the project has condensation, wet cleaning, or industrial pollution, review C2 or C3 instead.

Starting System Pattern

Layer	Typical role	Notes
Surface preparation	Remove oil, dust, loose rust, and poorly bonded old coating	Power-tool cleaning may be acceptable for low-risk interiors; confirm the project requirement.
Primer	Light anti-rust or adhesion primer	Choose based on substrate and expected topcoat.
Topcoat	Alkyd enamel, acrylic enamel, or compatible interior finish	Used when color, appearance, or cleanability is required.

Technical Review Points

• Confirm whether the steel will remain dry during service.
• Check compatibility with any existing shop primer or maintenance coating.
• Avoid over-specifying heavy systems where handling, drying time, and cost matter more than corrosion resistance.
• Confirm current Qilu Paints TDS/SDS, packaging, color, and shelf life before quotation.

Related Qilu Paints Products

• Alkyd Anticorrosive Primer
• Alkyd Enamel
• Acrylic Enamel Economy Grade