3M Aluminum Foil Tape 425

Overview

3M Aluminum Foil Tape 425 combines a nominal 3 mil dead-soft aluminum foil backing with a transparent acrylic adhesive. 3M describes it as thermally conductive, resistant to chemicals, able to withstand flame, weathering, moisture and UV, and a heat- and light-reflective tape with a very low moisture-vapour transmission rate, which makes it a good sealant; the dead-soft foil conforms to curved and uneven surfaces. The adhesive gives long durability but removes cleanly after harsh masking applications. According to the data sheet (September 2024) the total tape thickness is 0.12 mm (4.6 mil) with a 0.07 mm (2.8 mil) backing, 180 degree peel adhesion of 5.1 N/cm, tensile strength of 49 N/cm (28 lb/in), elongation at break of 6%, long-term temperature resistance from -54°C to 149°C, and a water vapour transmission of 0.77 g/m2/24 h. It is recognised under UL 746C (File E 122798) and UL 723 Class L low-flammability rating (File R 7311), can be certified to L-T-80C and meets FAR 25.853(a). Typical uses include aircraft paint-stripping maskant, moisture barriers in appliances, heat reflection and dissipation, holding wires and cooling coils, repairing truck trailers and aircraft, and general sealing and patching indoors and outdoors. Apply to a clean, dry surface above 0°C. Standard rolls are 55 m (60 yd); 3M does not intend the tape for medical use. Shelf life 24 months.

Specifications

Base Type

Dead-soft aluminum foil backing with acrylic adhesive

Service Temperature

-54°C to +149°C

Certifications

UL 746C (File E 122798), UL 723 Class L (File R 7311), FAR 25.853(a), Can be certified to L-T-80C

Technical Information

• Dead-soft aluminum foil; 0.12 mm total thickness; acrylic adhesive; peel adhesion 5.1 N/cm
• -54°C to 149°C long-term; flame resistant: UL 723 Class L; meets FAR 25.853(a)
• Heat and light reflective; very low moisture-vapour transmission; 55 m (60 yd) rolls

Typical Applications

• Heat shielding and heat reflection
• Sealing seams and joints in HVAC and duct work, moisture barriers in appliances
• Masking for paint stripping and chemical processes; holding wires and cooling coils

Industries

Technical Documents