105/209 Epoxy is used 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. 105/209 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. 105/209 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 105/209 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.

Handling characteristics

Mix ratio by volume (300 Mini Pump ratio) · · 3 parts resin : 1 part hardener

by weight· · · · · · · · · · · · · · · · · 3.59 : 1

Mix viscosity (at 72°F) ASTM D-2393 · · · · · · · · · · · 650cps

Pot life (100g at 72°F) · · · · · · · · · · · · · 40to50minutes

Working time, thin film* · · · · · · · · · · · · · · 3to4hours

Cure to a solid, thin film*· · · · · · · · · · · · · 20to24hours

Cure to maximum strength · · · · · · · · · · · · · 4to9days

Minimum recommended temperature· · · · · · · · · · 70°F (21°C)

*Epoxy cures faster at higher temperatures and in thicker applications.

Physical properties of cured epoxy

Specific gravity · · · · · · · · · · · · · · · · · · · 1.16

Hardness (Shore D) ASTM D-2240· · · · · · · · · · · · · · 82

Compression yield ASTM D-695 · · · · · · · · · · · · 12,000 psi

Tensile strength ASTM D638 · · · · · · · · · · · · · 7,300 psi

Tensile elongation ASTM D-638· · · · · · · · · · · · · · 3.6%

Tensile modulus ASTM D-638· · · · · · · · · · · · · 3.98E+05

Flexural strength ASTM D-790 · · · · · · · · · · · · 12,500 psi

Flexural modulus ASTM D-790 · · · · · · · · · · · · 3.97E+05

Heat deflection temperature ASTM D-648 · · · · · · · · · · 117°F

Onset of Tg by DSC · · · · · · · · · · · · · · · · · 122°F

Ultimate Tg · · · · · · · · · · · · · · · · · · · · 130°F

Annular shear fatigue @ 100,000 cycles · · · · · · · · · · 9,900 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 a possible color shift if very old and new hardener are used on the same project.