Robert Biegler
Senior Member
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It seems to me that is quite relevant experience. If you want something more specific to your plan, the Galeón Andalucía is available for sail training: EL GALEON - Sail Training International https://sailtraininginternational.org/vessel/el-galeon/Well, in my defense, I have been through a hurricane in a long-lining vessel in the middle of the Gulf of Mexico on a boat of not 20 meters with only myself, the captain, and his dog where the engine was unable to return us to shore such that we were sucked back out to sea and through the eye of the storm during which time, which is to say the time in the storm and not in the safety of the eye, I was forced to crawl across the bow and right the rope that attached his parachute anchor as best I could to a metal post meant to hold it that had been fully bent over from the power of the storm and, afterward, spending the entirety of the night listening and being shaken in horror as the hull of the ship was lifted several meters into the air and smacked down upon the water over and over and over again. Whereas, on good trips, we would be out for two to four weeks waking before dawn and fishing past dusk. However, it may be that I am not able to fully grasp this great discomfort of cruising on a sail boat of which you mention.
That would give you an idea what it takes to handle that sort of rig.
I think you should take Rumars' comment into account:
What is your motivation in sticking to the mixed aluminium and glass hull? The original motivation, lightning protection, seems groundless now, seeing that lightning protection for composite structures consists of adding electrically conductive material. To be fair, the aluminium parts you have drawn probably will do the job, provided that the masts and rigging connect to the metal, but I can see no advantage over an all aluminium hull, but a number of drawbacks.Be advised that in larger sizes one off construction economics tend to favor metal or cored builds, not monolithic glass.
If the attraction is that glass and resin may be cheaper than aluminium in China, take into account the materials and time needed to make the mold to build the glass hull.
One thing not mentioned yet is that metal hulls normally have internal structure: stringers and bulkheads or ring frames. If you have those, then inserting a glass hull becomes much more complicated. I don't think building the glass hull separately and then inserting it into the aluminium structure would be feasible. You would have to build the aluminium hull, add a mold, then build the glass hull inside that, then remove the mold. The glass hull would be weakened by wrapping around the internal aluminium structure. You would have to compensate for that.
You could build the aluminium structure out of plate thick enough that it needs no additional stiffeners, but then it needs to be much heavier. Or you could reduce the aluminium structure to just an external keel and a pair of bilge keels or thick rubbing strakes at the bilge.
As far as I know, any continuous composite structure needs to get the resin into the fibre all in one go, and it would be a bad idea to lay out the glass, then wet out one bit, let it set, wet out the next bit, and so on. A local sailor building a trimaran 8 metres long, the main hull weighing perhaps 200 kg, still recruited five volunteers to help him get the resin in all in one go. I doubt that a single person could hand laminate a hull of the size you envision even with slow resin. I don't even know whether it is possible to wet out 30 mm thick laminate by hand.
Resin infusion would let you put all the glass where it belongs over weeks or months, but then you would still need to mix 30 tons of resin and suck it into the laminate all in one go, and you would need all the extra material and equipment, such as large vacuum pumps. And if anything goes wrong, throw it all away and start over. If you build the aluminium structure and join a mold to it, that join will have to be airtight, or the infusion is not going to happen. You will suck in air.
With all aluminium, work can stop and start again any time you like, and you save the time and material for building a mold. Even then, I would let professionals do the job. Just fitting out a hull that large on your own is likely to take years of full time work.
There is a precedent for a single man building a vessel near the size you intend, SV Seeker. It is all metal, avoiding the scheduling problems outlined above, I think it took 10 years of full time work to get it to float, and it is a cautionary tale because Doug insisted on ignoring all advice, came up with his own solutions that create more problems than they solve (my favourite is the mermaid-contour diagonal braces that put sharp metal edges just above the upper bunks), and for all the work he put in, ended up with a vessel that is not fit for purpose despite further years of work after the boat first floated.
I very much agree with this:
Get plans from a source such as Wooden Rowboats: Classic pulling boats, sliding seat shells and wherries, and high-capacity dinghies https://www.clcboats.com/shop/rowboats/, work out how to build a mold, then build in glass, build the aluminium structure, and join the two together.try building a little dinghy first for your ship, and see how long that takes you.
I look forward to seeing what you have come up with.As for moulding, I have devised a concept to avoid needing as much and will test it tomorrow.
I may be able to find an article on someone building a glass-hulled canal barge, perhaps half the length of what you intend, but still massive. That might have useful information.