Can I trust wood-core construction?
QI am interested in buying a boat in Holland which, I am told, is constructed via vacuum infusion with a sandwich construction. I've performed the usual Google diagnosis and discovered that weaknesses are water ingress compromising the wood core if the laminate is punctured in any way – pretty likely on my drying mooring eventually through wear and tear – and also the delamination of the core from inner and outer skins for various reasons.
She’s a Koopman Foxx 30 and is only a few years old. The brokers tell me she’s made of 15mm Corecell wood, vacuum infused with epoxy, two layers of laminate inside and out, with extra thickness below the waterline. Apart from this construction method, she’s as near perfect as my dream boat will ever be, but I'd appreciate an 'expert' view on whether I can trust this technique. Are there many boats around built like this? Robert Durnford
ABen Sutcliffe-Davies replies: The boat you are looking at will probably be stiff, light and is well insulated so will suffer little condensation, It is an affordable and strong way of building a boat and it seems to be back in fashion, having been out of vogue for a few years. Corecell is a closed-cell foam used for sandwich construction rather than wood, so it might be worth checking exactly what the core is made of.
If it is a wood core, cedar pine used with good consideration for moisture conditions will be as good as any other boat. If it is balsa, I would be more hesitant. Balsa is extremely absorbent, and loses its strength when soaked. Water can seep in through even a tiny crack and send the whole boat rotten. A foam core is much less absorbent, though it can still soak up water slowly. All types of core can also be vulnerable to delamination from the outer skins, particularly if there have been collisions, overheating, or inadequate application of epoxy.
The important thing to look at are the skin fittings. Hull appertures must be properly sealed to avoid water ingress. Then check hull strong points, which should have significant reinforcement.
If the boat has been well built and cared for it should be fine, but the only way to find out is to take a surveyor along to go over every inch of the hull to check for voids or mositure, which signify trouble.