Sunday, 11 May 2008

Epoxy for boat building

Epoxy has in many ways changed the face of wooden boat construction,probably those most known persons to have actually raised the level of epoxies being really well understood,would be the Gougeon Brothers from Canada,who made their own epoxy brand,the West System (wood saturated epoxy treatment) a prooven world leader brand since the mid seventies,their book on the subject Wood and West System Materials (1979) is well worth finding,most informations you will require are to be found in that publication.

We sell our own brands,its an issue of us buying bulk and using what we know about ourselves,it was Dudley Dix,when building his Didi 38 design for himself,that introduced me to an epoxy brand he had tested prior to building,that saw me first use the same epoxy system on my own boat Flying Cloud ten years back,which is Dix 43 made from wood/epoxy rather than the normal steel.

Shell Chemicals made an epoxy called Epikure 816,this is the base for many re branded systems you will find world wide,we have left it just as Epoxy 816 for simplicity and when Shell Chemicals sold out to Resolution,we renamed it as Resolution 816 epoxy.The epoxy is no use without a hardener,we supply and use CV 140 cure agent and 205 cure agent.Both are mixed in a ratio of 100 grams of epoxy to 65 grams of cure agent,either the 140 or 205.

Use the thicker 140 cure agent (amber) for construction and back filling of joints and epoxy fillets,then the 205 cure agent (clear) for wetting out and applying glass tapes or cloth,the 205 being thinner than the 140 makes such opperations a lot simpler.

Saturation? this is probably not a correct term,we say 'envelope' which probably is closer to what we do when we apply thin epoxies to a wood structure,the 'envelope' of epoxy is all that is needed to stop the ingress of moisture to the wood and ply.We once had a visit from a technical guy,he brought a piece of wood he had vacume saturated with thin epoxy,which made the wood so solid it was turned into a hard plastic lump ,it would have sunk in water for sure!


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