PPG PR-1750 Class A is a two-part, manganese dioxide cured polysulfide sealant for aircraft integral fuel tanks. It is designed for brush sealing of fasteners in fuel tanks and other fuselage sealing applications. The uncured material can be applied by brush in thicknesses up to 25 mils and cures at room temperature to a resilient sealant with excellent adhesion to common aircraft substrates. Service temperature is −54 to 121 °C (−65 to 250 °F), with intermittent excursions to 182 °C (360 °F).
Application Properties (AMS 3276 Class A test methods)
- Colour: Part A black, Part B beige, mixed dark grey
- Mix ratio by weight A:B 10:100; base viscosity 300 P (30 Pa·s)
- A-1/2 (25 °C, 50% RH): application life ½ hour; tack free <10 hours; cure to 35 Shore A 24 hours
Performance (cured 14 days at 25 °C)
- Specific gravity 1.57; non-volatile content 86%; ultimate hardness 50 Shore A
- Peel strength (100% cohesive, after 7 days at 60 °C in JRF or JRF/salt water): 34–37 pli (151–165 N/25 mm) on anodised aluminium, Alodine aluminium, titanium, stainless steel and IFT coating; titanium and stainless steel primed with PR-148
- Hydrocarbon resistance (AMS 2629 JRF, 7 days at 60 °C): weight loss 5.0%; swell 10.1%
- No cracking or loss of adhesion at −54 °C
Packaging and Storage
- Two-part kits and Semco® cartridges
- At least 9 months below 27 °C (80 °F) in unopened containers
| Packing | 6 OZ |