Loctite SF 7400 Red Marking Ink – Solvent‑Based, –35°C to 145°C

Loctite SF 7400 is a solvent‑based, dark red marking ink engineered for use on electronic components and assemblies. It is ideal for indicating adjustment points, sealing calibrated parts, and marking tested or set points with high visibility. The ink dries to a tack-free film in approximately 5 minutes and cures within 6 hours, allowing production to continue with minimal delays.

This red varnish adheres reliably to both metals and plastics and operates across a temperature range of –35 °C to +145 °C, making it suitable for automotive electronics, aerospace components, and industrial automation applications. Once cured, the ink forms a pigmented organic polymer film that is removable only via mechanical abrasion followed by solvents like MEK or butyl acetate.

Loctite recommends thorough container shaking before use and application at thin films (~100 µm) for optimal performance. Storage between 8 °C and 21 °C preserves consistency; avoid oxidizers and store away from ignition sources due to flammability.

Key Specs Technology: Solvent-based, pigmented organic polymer Color: Dark Red Liquid Tack-Free Time: ~5 minutes (100 µm film) Full Cure: ~6 hours (100 µm film) Operating Temp Range: –35 °C to +145 °C Adhesion: Excellent on plastics and metals Removal: Mechanical plus butyl acetate or MEK Storage: 8–21 °C, flame-resistant conditions