When it comes time to pick the epoxy to cover your beautiful hand built kayak with, a common question that is well worth asking is which epoxy holds up best? Now I’ve only personally used West Systems epoxy and that has consistently been with their 207 hardener. I have also consistently used Interlux Traditional Spar Varnish overtop of the epoxy.  I’ve been happy with the results over 16 years now.

However, Vaclav Stejska of One Ocean Kayak did a pretty well put together test that compared:

• West System 105 resin and 206 hardener
• West System 105 resin and 207 special coating hardener
• Raka 127 resin 350 hardener
• MAS resin and slow hardener
• System Three resin and medium hardener
• East System 1032 resin and 834 slow hardener

The test panel that Vaclav put together had a section for each of these epoxy resin & hardener combinations. Then for each epoxy, part of the section was varnished and part was left unvarnished using Z*Spar Flagship 2015 for the varnish. Finally Vaclav added a strip of opaque plastic down the middle to add light protection to a part of both the varnished and unvarnished sections for each epoxy to test the impact of light exposure, and as it turned out to inadvertently test the effect of extended exposure to moisture.  The complete test panel was then left sitting outside exposed to the sun. That gives us a total of 24 different combinations being tested with this one test panel, which makes for a pretty extensive test and Vaclav recorded and reported on the results after 2, 6, and 12 months.

Now thinking back to the last time I did a statistics course and having some vague memories about experimental design, I know you would need a lot more than just the one panel to come up with a solid, repeatable conclusion. Nonetheless, this is still the best comparison that I’ve seen for so many different epoxies in one spot. One other thing that I’ll point out is that Vaclav did his test starting in March 2000. That means it’s over 10 years old now and it is quite likely that the epoxy manufacturers have updated their products in that time. Here is the link to the Epoxy Test at One Ocean Kayaks.