3M AC-251 Black Class B Aerospace Sealants are designed for aircraft windshield, window and canopy applications. When mixed, the two-part manganese dioxide cured polysulfide forms a thixotropic paste easily dispensed with a cartridge applicator or spatula.
Features
- Resistant to UV exposure and weathering
- Retains shape and volume during cure
- Seals acrylic, glass and polycarbonate without crazing
- Compatible with 3M Adhesion Promoter AC-137
Applications
- Aircraft windshields, windows and canopies
Specifications
- Class B-1/2: application time 30 min; tack-free 4 h; cure to 30A in 4 h
- Mix ratio base:accelerator: 10:1 by weight
- Service temperature: -54 °C to 121 °C
- Ultimate hardness: Shore A 48–55; specific gravity: 1.6
- No crazing on MIL-PRF-5425 acrylic and AMS-P-83310 polycarbonate
| Packing | 3.5 OZ |