Wood building methods

Hi,

I've been looking into building a wood sailboat and have found a couple plans available online. Some methods seems to advocate making the hull using lofted shapes, fiberglassed, flipped, fiberglassed on the inside, and then stringers and bulkheads added. Others do the reverse, bulkheads first, stringers, and then hull. Will there be a difference in hull strength? I guess you do the complete hull first, you would have a layer of fiberglass between the hull and the bulkhead/stringers, but doing the bulkheads and stringers first seems to be a more efficient process. Or is there any actual difference?

Thanks,

 

The most efficient, fastest build method for amateurs is stitch and glue monocoque construction. Many home builds fail; so choosing a method you can complete is important. So, your assertion is actually incorrect. Building the guts first is generally harder.

The strength differences would emanate from the hull thickness, in general. However, fiberglass over wood hull and a wood hull are not directly comparable on thickness.

A very thin okume plywood with glass both sides is a tough competitor for any all wood boat.

 

I've only built one boat that was Fibreglass / ply / fibreglass and that was stringers and bulkheads in first.. That was a real pain to glass round all those joins.. Given the choice now, I would glass the hull inside and out first and then fit the bulk heads after..
you can glass the bulkheads before fitting and then its a glass /glass join .

 

Check this thread out for a good way to do it
Construction of a trailer yacht Lion 550 Adrenaline https://www.boatdesign.net/threads/construction-of-a-trailer-yacht-lion-550-adrenaline.58265/page-3#post-838456

 

Thanks, that's a great thread. Now I have another method to ponder over. I guess most of the strength will be coming from the fiberglass?

 

No. The 'strength' comes from the combination and the internals. Each part of the ply hull sandwich contributes to the overall structure, but not sure how they finish the lion inside; it might be no glass inside.

Strength is actually a rather ambiguous term. It might be simple to default to say tensile strength as strength, but a boat's overall ability to handle seas and shores, wind and rain is not based on simple strength. For example, plywood is very stiff, and so the excellent boat linked will be stiff by using ply. Conversely, marine foam is not as stiff, generally, and so it must be thicker with glass both sides to become stiffer.

The Lion could only be a fast build from a kit. You would rather easily get bogged down with the framing, imo.

 

I would say that for amateurs, plywood construction is the easiest. If it will be covered in fiberglass, the seams and fits don't need to be perfect.