When working with WEST SYSTEM 105 Epoxy Resin, this is the hardener to use where a clear finish is desired.207 Special Clear Hardener is formulated for coating and fiberglass cloth application where a clear, moisture-resistant, result is preferred. For fiberglass layups over wood, 207 Special Clear Hardener allows the natural grain of the wood to show through. Other uses include carbon fiber layups where a clear effect is desired. This hardener cures to a light amber color, similar to traditional spar varnish.Other properties207 Special Clear Hardener is formulated to self level for smooth finishes, and for wetting out and bonding 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. Although it contains a UV stabilization additive, it still requires long-term UV protection with a quality marine paint or varnish.Meter the mix207 Special Clear Hardener requires mixing with 105 Epoxy Resin at a 3:1 ratio. To make this easy, for Group Sizes A, B and C, we strongly recommend purchase of the 300 Mini-Pump Kit (Model 3405669) which enables mixing the desired quantity in the exact proportions that you need. Large quantities can be metered with the model 306-23 Special Purpose Resin/Hardener pump (Model 128845), which also dispenses hardener and 105 Epoxy Resin at a ratio of 3:1.Key FeaturesExcellent for use in hot or humid conditionsProduces a clear, low-blush finishProvides excellent adhesion for bonding applicationsContains UV stabilization additive, but still requires long term UV protection with quality marine paint or varnish300 Mini-Pump Kit recommended for Group Sizes A, B, and C306-23 Special Purpose Resin/Hardener Pump (Model 128845) recommended for large quantitiesPair the Group Size of the hardener you choose with the correct Group Size of 105 Epoxy Resin.207 SC-Size hardener should be paired with 105 C-Size Resin. Selection Guide