PPG PR-1428 Class A is a low adhesion access door sealant. Service temperature is −54 to 121 °C, with intermittent excursions up to 135 °C. It is used for access doors and in the fabrication of form-in-place (FIP) gaskets. It is a two-part, manganese dioxide cured polysulfide applied by brush in thicknesses up to 25 mils, curing at room temperature to a removable seal. Tests are run to MIL-S-8784 Class A methods.
Application Properties (A-2)
- Colour: A black, B red, mixed dark red; mix ratio by weight 10:100
- Base viscosity 400 P (40 Pa·s)
- Application life 2 hours; tack free under 10 hours; 30 Shore A in 16 hours
Performance
- Specific gravity 1.49; non-volatile content 92%; hardness 50 Shore A
- Peel below 4.44 N/25 mm, 100% adhesive failure (easy removal)
- Weight loss 5.0% after 7 days in JRF at 60 °C; no cracking at −54 °C
Storage
- At least 12 months below 27 °C in unopened containers; kits and Semco cartridges
| Packing | 6 OZ |