West System 205 Fast Hardener
Product Description
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.
Pot Life at 72F (22C): 9 to 12 minutes
Cure to a solid state: 6 to 8 hours
Cure to maximum strength: 1 to 4 days
Minimum recommended temperature: 40°F (4°C)
105/205 West System Epoxy is used for general coating and bonding applications at lower temperatures and to produce a rapid cure that develops its physical properties quickly at room temperature.
105/205 forms a high-strength, moisture-resistant solid with excellent bonding and barrier coating properties. It will wet out and bond to wood fiber, fiberglass, reinforcing fabrics, foam and other composite materials, and a variety of metals. 105/205 Epoxy can be thickened with WEST SYSTEM fillers to bridge gaps and fill voids and can be sanded and shaped when cured. With roller applications, it has excellent thin-film characteristics, allowing it to flow out and self-level without "fish-eyeing." Multiple coats of 105/205 Epoxy create a superior moisture barrier and a tough, stable base for paints and varnishes. It is formulated without volatile solvents. It has a relatively high flash point, no strong solvent odor and does not shrink after curing. It is not intended for clear coating natural finished wood.
Epoxy Handling characteristics
Mix ratio by volume (300 Mini Pump ratio) · · 5 parts resin : 1 part hardener
By weight: 5.07 : 1
Mix viscosity (at 72°F) ASTM D-2393 : 975cps
Pot life (100g at 72°F): 9 to 12minutes
Working time, thin film*: 60 to 70minutes
Cure to a solid, thin film*: 6 to 8hours
Cure to working strength: 1 to 4days
Minimum recommended temperature: 40°F (4°C)
*Epoxy cures faster at higher temperatures and in thicker applications.
Physical properties of cured epoxy
Specific gravity: 1.18
Hardness (Shore D) ASTM D-2240: 83
Compression yield ASTM D-695: 11,400 psi
Tensile strength ASTM D638: 7,900 psi
Tensile elongation ASTM D-638: 3.4%
Tensile modulus ASTM D-638: 4.08E+05
Flexural strength ASTM D-790: 14,100 psi
Flexural modulus ASTM D-790: 4.61E+05
Heat deflection temperature ASTM D-648: 118°F
Onset of Tg by DSC: 129°F
Ultimate Tg: 142°F
Annular shear fatigue @ 100,000 cycles: 10,600 lb
Storage/Shelf life
Store at room temperature. Keep containers closed to prevent contamination. With proper storage, resin and hardeners should remain usable for many years. After a long storage,verify the metering accuracy of the pumps. Mix a small test batch to assure proper curing. Over time, 105 Resin will thicken slightly and will therefore require extra care when mixing. Repeated freeze/thaw cycles during storage may cause crystallization of 105 Resin. Warm resin to 125°F and stir to dissolve crystals. Hardener may darken with age, but physical properties are not affected by color. Be aware of apossible color shift if very old and new hardener are used on the same project.
