Steel and plywood hull?

[pdvjak]

Does anyone have any experience with or thoughts about constructiong a multichine hull based on a keel box (for bolt-on keel structure) and first one or two chines up to one foot above waterline, creating tankage, plus full bulkheads, constructed in steel, with (pretty high) plywood/glass/epoxy freeboard, structurally integrated interior, deck and (almost no) superstructure? (Maybe even bamboo/glass/epoxy rigging, but that's another story.... and another thread......;)

I can have a strong steel 'box' designed and constructed here in Jakarta VERY cheaply and easily and plywood and labor are also really cheap here, so that more budget is available for fitting out. I use Chine Hull Designer 1.82 and from that I can generate full size patterns and figure out design characteristics

LOA would be around 38-40 ft. Not looking for a racer but for something I can trust and handle. My thinking is that, apart from 'ease' and 'costs', other benefits might include stifness, strength (you could run THIS onto a reef and survive!), weight distribution (especially with bamboo rig...;)?

I'd be prepared to 'cover' the steel with ply/epoxy and have all steel gridblasted and zinc-coated, and do whatever is needed to exclude corrosion from the threats.

Would the steel different temperature expansion cooficient be a problem? (I'd only sail in tropical waters...:)

Would adhesion of epoxy on zinc-rich coating be a problem?

Any input will be much appreciated. Thank you.

[gonzo]

I don't see any major difficulties. Many large sailing ships were built with wood planking over steel frames. I think that a flexible adhesive or caulk between the plywood and metal framing would be better. Do you have a method of sealing the chines? I think that fiberglassing over them is one possiblity. However a wooden batten covering the end grain would work fine too.