We have restored small boats for decades and for fiberglass repairs often used WEST System 105 Epoxy Resin with 206 Slow Hardener. During our 2013 restoration of our 1953 wooden Sunfish ZIP we decided to finish the fir plywood hull bright, and our marine carpenter friend Keith suggested WEST System 207 Special Clear Hardener. We tried it and have been very pleased with the results, even seven years later.
Keith had used the 105 resin with the 207 hardener for years on the interior finish of several high-end yachts for an epoxy mix that is easy to apply and provides a tough, glossy finish. The key feature of 207 is that it does not turn amber like the 205 Fast, 206 Slow, and 209 Ultra Slow hardeners. It includes a UV inhibitor, so if the cured epoxy finish does not get extended exposure to ultraviolet rays, there is no need to add additional protective coats of UV varnish. That sounded like a time-saver to us, as ZIP is stored indoors or covered when not in use. WEST System 207 is odorless and does not turn cloudy or blush in hot, humid conditions, which is pretty much every day here in Florida.
One of the big benefits of the epoxy coatings we’ve used is they have stopped the checking of plywood without requiring fiberglass sheathing. We applied 207 to the fir plywood deck of ZIP in 2013, and there has been no checking since then. At the same time, we had repainted the bottom, without first coating the plywood with epoxy, and that plywood has checked. The WEST System 105 resin with 205 Fast Hardener that we applied to our Penobscot 14 in 2016 has also prevented checking on the BS1088 okoume plywood.
WEST System’s technical support team confirmed our observation that a couple of coats of resin with any of the hardeners is a good strategy when working with plywood, with 207 being the best choice for a bright finish. Like the other WEST System hardeners, 207 with 105 resin can also serve as a structural adhesive for construction, fairing, and repair, though WEST notes it is not as economical nor as well suited to thickeners as the other hardeners.
The mix ratio for 207 is three parts resin to one part hardener (209 is also 3:1; 205 and 206 are 5:1), so we bought the WEST pump kit that dispenses the correct amount without the fuss of measuring. Application as a coating is straightforward. We used the WEST System 800 roller cover to avoid the shedding and disintegration that we have experienced with other roller covers. Thin applications of two coats are best to prevent runs and sags, and the second coat can be applied without rinsing as there is no amine blush. The 105/207 mix is not as thin as that with the slow-curing hardeners, and that helps to eliminate runs. The subsequent coat can also be applied without sanding as long as the first coat has not fully cured (generally, within 10 to 15 hours).
Audrey and Kent Lewis enjoy messing about in their small armada of boats in the coastal waters of Northwest Florida. Their boats’ adventures are chronicled in their blog, Small Boat Restoration.
The WEST System 207 Special Clear Hardener is available from a wide range of marine and hardware stores. A 10.6 oz can retails for about $50.
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