WEST SYSTEM brand resins and hardeners, form a two-part epoxy system developed by Gougeon Brothers specifically for wood and composite construction. WEST SYSTEM epoxy is recommended by Rutan Aircraft Factory for certain homebuilt aircraft applications, particularly where a moisture resistant epoxy is desired. 105 Resin is the base material on which all of the WEST SYSTEM epoxy systems are built. The resin is a clear, light amber, low-viscosity liquid. It is designed specifically to wet out wood fiber. With roller applications, it possesses excellent thin film characteristics in flowing out and is self-leveling without fish-eyeing. Its relatively high flash point makes it safer to work with than polyesters. It can be cured in a wide temperature range, then sanded and shaped. It cures quite clear so that the natural finish shines through.
205 Fast Hardener, when mixed with the 105 Resin in a ratio of 5 parts Resin to 1 part Hardener, yields a high-strength, rigid solid with excellent cohesive properties and provides an excellent moisture vapor barrier. The 105 Resin/205 Fast Hardener has a pot life of 10-15 minutes at 70°F. It is also recommended in coating applications where natural finishing is desired. Partial cure time at 70°F is 5-7 hours. 206 Slow Hardener is a low-viscosity mixture of polyamines. The 105 Resin/206 Slow Hardener has a pot life of 30-40 minutes at 70°F. It is normally used when extended time is needed for large coating and bonding applications. It is especially well suited to working in warmer climates. Partial cure time is 9 hours at 70°F. Order by size and hardener. Pump sold separately.
Choose the right hardener to control the cure time of 105. Epoxy Resin at the temperature at which you will work.
Select your hardener to give you the pot life you want at the temperature and conditions in which you will work. #205 Fast Hardener, mixed at a 5:1 ratio with #105 Resin, results in a pot life of 9-12 minutes at 72°F, with solid cure in 6-8 hours. It has a minimum recommended working temperature of 40°F. #206 Slow Hardener, mixed at the standard 5:1 ratio with #105 Resin, has a 20-25 minute pot life at 72°F with 12-18 hours required for solid cure. It has a minimum recommended working of temperature of 60°F. 209 Extra Slow Hardener, mixed at a 3:1 ratio with #105 Resin, results in a pot life of 20-25 minutes at 72°F, with 10-15 hours required for a solid cure.
Slow Hardener for 105 Epoxy Resin
10 to 15 Hours (Working Time 90-110 Minutes) at 72 F