West System 105 Epoxy Resin

105 Epoxy Resin is the base material on which all West System 105 epoxy compounds are built. It is a clear, pale yellow, low-viscosity liquid epoxy resin. This liquid epoxy resin cures to a hard, solid plastic with superior physical properties. Formulated for use with West System hardeners, it can be cured in a wide temperature range to form a high-strength solid with excellent moisture resistance.

• Best for use in small pours to fill cracks and voids or thin coatings on bar tops or other wood projects
• For smaller pours, do not pour more than 0.5" per layer. For larger pours, do not pour more than 0.25" per layer
• Can be layered with multiple pours to build up thickness
• Suitable for outdoor applications
• Can be used to keep cracks from expanding

How 105 Epoxy Resin Cures
WEST SYSTEM Epoxy’s cure times are based on an ambient temperature of 72°F. In warmer temperatures, epoxy cures faster. Here is what you need to know to ensure adequate working time when using epoxy in warm conditions.

Epoxy cures by a chemical reaction between the resin and hardener that releases heat, called an exothermic reaction. The larger the volume of epoxy the more heat that is generated. Many epoxy users have seen pots of epoxy smoke and bubble due to uncontrolled exotherm. The good news is you can prevent this. A good rule of thumb for gauging cure speed is that for every 18°F increase above 72°F, the working time and pot life will be cut in half. To maximize the working time of the epoxy, consider how much time you need and what temperature you’ll be working at, then select the hardener accordingly. For warmer temperatures, we recommend the 206 Slow Hardener or 209 Extra Slow Hardener.

Avoid exotherm by using smaller pours when casting and working in a cool environment.

Do not add extra hardener to 105 Epoxy Resin as this can result in uncured epoxy or compromised cure strength.

Uses
105 Epoxy Resin is designed to wet out and bond with wood fiber, fiberglass, and reinforcing fabrics. Modifying this epoxy with West System 404 High Density Filler or 410 Microlight Filler creates an excellent structural adhesive or fairing compound. Epoxy thickened with adhesive (high-density) fillers makes structural bonds, bridges gaps, and fills voids. Epoxy thickened with fairing (low-density) fillers is easily sanded and shaped after it cures.

This epoxy is also a great coating material. Applied with a roller, it offers excellent thin-film characteristics. It will flow out and self-level without “fisheyeing.” By combining it with blush-free 207 Special Clear Hardener, you can create a natural finish. You’ll just need to add a couple of coats of varnish for UV protection. This is a good alternative that builds mil thickness quickly, saving time and effort. The results are long-lasting.

Pairings
105 Epoxy Resin/207 Special Clear Hardener mixtures cure clear so you can achieve a natural finish when coating with varnish.

Pair 105 Epoxy with corresponding letter size of 205 Fast Hardener, 206 Slow Hardener, 207 Special Clear Hardener or 209 Extra Slow Hardener.

Group Size A Resin - use with Group Size A Hardeners

Group Size B Resin - use with Group Size B Hardeners

Helpful tip: Use 300 Mini Pumps to always dispense correct ratio of resin and hardener. One full pump-stroke of resin for every one full pump stroke of hardener is all you need to remember.