West System A Pack 105 Resin + 205 Fast Hardener

West System 105/205 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 fibre, fibreglass, 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. The formula can also be sanded and shaped when cured. When applied by roller, 105/205 epoxy has excellent thin film characteristics, allowing it to flow out and self-level without “fish-eyeing.”

105/205 epoxy can be used to create a superior moisture barrier and a tough, stable base for paints and varnishes. It is formulated without volatile solvents, resulting in a very low VOC content. It has a relatively high flash point, no strong solvent odour and does not shrink after curing. It is not intended for clear coating natural finished wood.

Handling Characteristics:
Mix ratio by volume (300 Mini Pump ratio): 5 parts resin, 1 part hardener
By weight: 5.19 : 1
Acceptable ratio range by weight: 83:1 to 6.20:1
Mix viscosity (at 72°F) ASTM D-2393: 975 cps
Pot life (100g at 72°F): 9 to 12 minutes
Working time, thin film*: 60 to 70 minutes
Cure to a solid, thin film* : 6 to 8 hours
Cure to working strength: 1 to 4 days
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

Storage/Shelf Life:
Store at room temperature and keep the 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 colour. Be aware of a possible colour shift if very old and new hardener are used on the same project.