Anonymous wrote:The method of building the interior first from CNC-cut interlocking pieces has to be much faster, and actually, building the hull is the quicker and easier part of building a boat, whether it's done before or after the interior, and whether it's being done by a first-time amateur or by a fully experienced professional. I'm now fully convinced that doing the hull skin afterwards is the quicker way to complete a plywood boat.

Doing the interior first as you have done and also as in Tapatya's build to some extent (final bulkheads used instead of temporary frames) makes a lot of sense. Being able to put the interior together while both sides are reachable has to be easier. The downside is that the stability of the frame without the hull's support is less and unless one has a great sense of imagination, it is much easier to decide/design a space when one can look at it as it is than as even the best computer rendering. I think a full size mock up (no cutting needed) would be helpful at least for me.

But it seems to me that there may be an intermediate option. The hull panels of the SibLim 7 are made from three pieces (four in the case of the bottom panel and bow transom). The forward join is in an area of the hull where there is conical twist as well as more curvature, whereas the after join is in an area where there is no twist and very little curvature. Whether they are made with a scarph, puzzle joint or butt block, it is difficult to make that forward join in situ, but much easier to make the after join in situ. So there is an argument for joining the forward and middle sections of the middle hull panels and topsides flat on the floor, assembling them onto the prebuilt interior, then adding the after sections in situ. And in the specific case of these after joins on the SibLim 7, puzzle joints and scarphs don't seem to offer any advantages, and, hidden as they are inside lockers, butt blocks would be the quicker and easier way to go with no disadvantages.

Any comments?

I like butt blocks. I have only built a 16ft boat and so the butt blocks were able to be in a flat spot. puzzle joints are new to me and yet it appears from past posts they are considered as strong as needed even though the glued area looks less than scarph or butt. Anyway, the one thing I would say about butt joints, is that they should be faired. A faired butt joint need not be hidden as the block is thin anyway. However the fairing also makes sure there is no nook for water to collect in and so even when hidden I would make sure it is faired.

I am also assuming that the hull is more than one sheet thick? As you have stated, the hull is one of the quicker parts to build and so using two layers rather than one thicker layer makes sense so long as the base layer is thick enough not to have flat spots in a curve. Thinner means lighter and easier to lift and place. The second layer would be cut when placing rather than CNC-cut.

Options

Annie has been giving us an ongoing demonstration of just how long it takes to install the interior items into a hull - measure, make templates and patterns, cut, offer up, scribe, trim, add framing, resin coat and glue in. The method of building the interior first from CNC-cut interlocking pieces has to be much faster, and actually, building the hull is the quicker and easier part of building a boat, whether it's done before or after the interior, and whether it's being done by a first-time amateur or by a fully experienced professional. I'm now fully convinced that doing the hull skin afterwards is the quicker way to complete a plywood boat.

But now I'm getting close to adding those hull panels, and it's worth reviewing how these might be put on.

It would be quite feasible to do as we did with Annie's SibLim, and notch the corners of the bulkheads, add chine logs, fair them in and then apply the hull panels one 8 x 4ft sheet of plywood at a time - not CNC cutting, but offering up the plywood sheet, drawing around the perimeter, cutting out, and making scarphs or butt joints in situ. This would be slower, but would save some CNC-cutting expense, and would avoid having to handle very long assembled hull panels.

It's also quite feasible to make up the full length of the hull panels and add them - provided that there is enough manpower available to handle them and manage the gluing process. RM do it this way. The longitudinal joints are done by stitching, filleting and glass taping, but the joins to the bulkheads can be done either with filleting and taping or with traditional framing and gluing.

But it seems to me that there may be an intermediate option. The hull panels of the SibLim 7 are made from three pieces (four in the case of the bottom panel and bow transom). The forward join is in an area of the hull where there is conical twist as well as more curvature, whereas the after join is in an area where there is no twist and very little curvature. Whether they are made with a scarph, puzzle joint or butt block, it is difficult to make that forward join in situ, but much easier to make the after join in situ. So there is an argument for joining the forward and middle sections of the middle hull panels and topsides flat on the floor, assembling them onto the prebuilt interior, then adding the after sections in situ. And in the specific case of these after joins on the SibLim 7, puzzle joints and scarphs don't seem to offer any advantages, and, hidden as they are inside lockers, butt blocks would be the quicker and easier way to go with no disadvantages.

Any comments?

Annie wrote: Well, I'm not sure how prudent I am - my form over the past couple of decades would appear to indicate the opposite if anything - but if the 7m variation can sail around the world, then taking my 8m to Fiji (as I have tentative plans to do) seems less than foolhardy.

Hey, you might as well dream while you build.

I wouldn't for a moment want to claim that the SibLim 7 can sail around the world. Only that it should be able to tackle the easier "milk run" trade wind passages across the Atlantic and South Pacific. Size does matter, bigger is better, more is more (BibMim), when the height of breaking waves is more than the beam of the boat is when knockdowns become more likely. As the GGR entrants are demonstrating, 32 - 36ft is a bit marginal for going nonstop south of the Great Capes. 40 - 50ft boats have a rather better track record, eg Hawk, sailed by Evans Starzinger and Beth Leonard, 47ft LOA.

I would say: dream on, but happiness is adjusting your dreams to realities and practicalities. Yes, SibLim 8 can go to Fiji, as could SibLim 7, but I would hesitate to take either down to Stewart Island. Can SibLim 7 sail from Japan to NZ? According to World Cruising Routes, it could be somewhat of a windward slog to get out to Guam or the Marshall Islands, so the rig had better be pretty good, but then it should be easier on the SE trades past Vanuatu.

Anonymous wrote: All the talk about southern ocean rollovers got me thinking about how, or whether, this boat could be made ocean-ready. I think it could, with a Mingming-style hinged companionway hatch that could be dogged shut and watertight.

Met this French couple who had an interesting take on this. At the bottom of the companionway steps beneath the dogged hatch were a pair or race car seats with 5 point harnesses - one on each side. Bolted to the bulkhead. 

In any event the majority of really bad weather seems to be at the edges of of the oceans rather than the middles (notwithstanding rotating storms).

Anonymous wrote:

Daivd 

Although I have a boat waiting for me in NZ, the idea of a kit to build and get me to NZ is very enticing.   I actually have a set of Wharram plans sat on my coffee table but SibLim 7m......

Peter

Hmmm,

a 23 foot boat from UK to NZ

You sure about that ?

Maybe I am just getting old (well OK I am) but I am thinking that might be marginal.

Perhaps not, I dunno.

Gary

I'm currently living and working in Japan...  It would be Japan to NZ

Peter