As many of you may already know, Lin and I have long been concerned with the over reliance on Epoxy as a wood adhesive, either for wooden boats or for wooden parts used on the exterior of glass boats. The three pages from the 18 page appendix in my book, Details of Classic Boat Construction, which are shown here, give you just a brief introduction to my concerns. In it we show the research we did over a 20 year period and the conclusions we reached. Just a few weeks ago we received an email from an amateur boat builder in Finland who asked, “It has been a few years since you wrote that appendix, do you think epoxy adhesives have been improved since then? And where can you get the resorcinol adhesives you talk about?”
I did some research and can definitely say that nothing much has changed. Epoxy still would not be my choice for any structural member of a wooden boat, nor for any joints on deck which will not be heavily protected by paint or varnish. Furthermore, I have used resorcinol in conjunction with fiberglass cloth successfully (eight years of constant exposure to sun and rough sailing so far) and would consider using it instead of epoxy with unidirectional fiberglass cloth or S cloth if I wanted to sheath a wooden hull or to lay over a laminated deck or plywood deck.
Resorcinol is not as easy to find as epoxy, but here in New Zealand you can buy it at any Carters building supply store. In Canada it is available on line from www.aircraftspruce.com/canada.html. In the USA www.Chemical-Supermarket.com run by DGR Industrial Products, Livermore California 1-408-221-7122 can supply not only DAP brand resorcinol, but two others with slightly different cure rates and temperature tolerances, G-1131 and Aerodux 500 which sets to full strength in temperatures as low as 59 degrees farenheit.
Click here to view the excerpts from Details of Classic Boat Construction.