Specifications:
West System Hardener selection-select a hardener for its intended use and for the cure speed best suited for your job in the temperature range in which you are working. 205 FAST HARDENER 205 Fast Hardener is a medium-viscosity epoxy curing agent. It is used in a majority of situations, at lower temperatures and to produce a rapid cure that develops its physical properties quickly at room temperature. When mixed with the 105 Resin in a five-part resin to one-part hardener ratio, the cured resin/hardener mixture yields a rigid, high-strength, moisture-resistant solid with excellent bonding and coating properties. Not intended for clear coating.
SPECS: Mix Ratio 5:1 Hardener Pot life at 72F 9-12 minutes
Cure to a solid state 6 to 8 hours
Cure to maximum strength 1 to 4 days
Minimum recommended temperature 40F 206 SLOW HARDENER 206 Slow Hardener is a low-viscosity epoxy curing agent for use when extended working and cure time is needed or to provide adequate working time at higher temperatures. When combined with 105 Resin in a five-part resin to one-part hardener ratio, the cured resin/hardener mixture yields a rigid, high-strength, moisture-resistant solid with excellent bonding and coating properties. Not intended for clear coating.
SPECS:
Mix Ratio 5:1
Hardener Pot life at 72F 20-25 minutes
Cure to a solid state 9 to 12 hours
Cure to maximum strength 1 to 4 days
Minimum recommended temperature 60F <207 SPECIAL HARDENER This hardener was especially developed for use with WEST SYSTEM Brand 105 Resin in coating applications where an exceptionally clear, moisture-resistant, natural wood finish is desired. Cures to a light amber color, similar to traditional spar varnishes. An ultraviolet inhibiting additive improves the resistance of a WEST SYSTEM 105/207 mixture to sunlight, but the cured epoxy surface will still require the additional protection of a quality UV-filtering varnish. 207 is designed to self level for smooth finishes, and to wet-out and bond fabrics. Although it provides good physical properties for general bonding applications, it is more difficult to thicken and less cost effective for this purpose than 205 or 206 Hardeners. It's also used for laminating veneers where bleed through at joints may be exposed to sunlight.
SPECS:
Mix Ratio 3:1
Hardener Pot life at 72F 22-27 minutes
Cure to a solid state 9 to 12 hours
Cure to maximum strength 4 to 7 days
Minimum recommended temperature 60F 209 EXTRA SLOW HARDENER 209 Extra Slow Hardener is formulated for use with WEST SYSTEM Brand 105 Resin for general coating and bonding applications in extremely warm and/or humid conditions or when extended working time is desired at room temperature. Provides approximately twice the working time of 206 Slow Hardener. Forms a clear, amber-colored solid with good physical properties and moisture resistance for bonding and coating applications. Not intended for clear coating.
SPECS:
Mix Ratio 3:1
Hardener Pot life at 72F 40-50 minutes
Cure to a solid state 20 to 24 hours
Cure to maximum strength 4 to 9 days
Minimum recommended temperature 70F | 
