Is it possible to build a liveaboard multi in 90 days?

http://www.cruisingnorth.com.au/

This is a pretty good daily account of what work needs to be done when. Thanks for posting the FusionCats link.

It would be nice, but I am thinking something simpler in the design. It would be cool to be able to know all of the pieces that there will be, and be able to just piece it all together.

 

It's the Wharram cats.
Like Gonzo said-plywood.
Have no idea of time/cost.


http://wharram.com/site/catalog/13

Google will give you lots of pix.

 

plywood may have been a fast method back in the day, but these days i beleive there are faster materials - which also happen to be lighter stronger and waterproof to boot. The problem with plywood is that its heavy, or if light ply is used you need lots of stringers and stiffeners - more work. It all needs to be sealed with epoxy to waterproof it. Then it still needs fairing and painting...

Building a multi fast, is quite an easy proposition provided your not too concerned with appearance. What i mean is, if your happy to build with 100% developable panels (which can only be curved in not more than 1 dimension) then you can build composite panels (or plywood) very rapidly and with little fuss. Look into what Rob Denny is doing with his proas and fast build methods - although not everything is easily found on the net.

The general idea is to infuse flat foam sandwich panels on a table and bend / twist / fold them into the bits you need. The main hull for example, is a long flat section with cored and single skin laminates all set out flat so the folds occur at the single skin laminate. Its all folded around into a U shape, and then finally closed with the 2 deck edges pulled down and meeting for a single tape join in the middle. For obvious reasons, you cant have a largely compound curved hull or it doesnt fold. The compound curve in the bows are added on later.

The method involves putting down a gelcoat then infusing your laminate with a vinyl ester resin. The panels are therefore finished and dont require , fairing , painting or sealing etc... its just infuse and tape and done.

Another method would be to design the boat in a similar method to "stratosphere" 60ft cat which didnt end up doing much but sitting on a beach... But the idea is to make a single eliptical body of revolution 1/4 or 1/2 mold, and use it to make the symetrical hulls and beams. Top and bottom, port starboard, etc etc tape them all together 2 tape joins a peice. Personally i would again infuse the laminates as i think its actually faster than hand laminating but old school handlayups could also be used.

If you had the single goal of fast building and didnt care so much about what shapes you want, its very easy to design a reasonably large multihull shell that could be mostly / entirely built within a month. But your resale will suffer because it wont look right, and therefore home builders usually want to build something that offers them a return of their very large "blood sweat and tears" time investment...

 

Sundevil said:-
"9 weeks is really good. Do you have any tips on how to get it done that fast? Did you build it at your home? How did it work?"

Yes. First you have to find a place to build it.
It's sometimes not an easy option to build it in a garage. I built my first 24ft Tri in the underground car space of my apartment block. The three hulls, cabin and wing deck were built as separate modular units. Carting them on the top of my car,up to the lake during the winter and storing them in a space in a boat shed. The boat was then assembled in the spring, in the open, and launched. A second Tri followed the same pattern. The Buccaneer was a little different. I went door knocking in a light industrial area close to home and rented space in a typical small warehouse with a flat level concrete floor, with power and water to hand. it was not expensive
I had only standard electric hand tools, but bought a Black and Decker radial arm saw for $95.00. I knocked together a workbench with standard 2 X 4 lumber. Most importantly I rented a power stapler, which speeded up the assembly, (with fast setting epoxy glue), in an easy way. I went to a lumber yard and selected spruce roofing boards, 16 ft long and 12" x 1" Picking ones with the least knots possible. These were ripped on the saw scarfing the pieces together as necessary, to form gunnels, stringers and keels. Plywood was a lightweight mahogany called Samba which I now think was probably Luan. It had a 3mm core with no voids and outer plies of 1.5mm, making 1/4" ply. Plywood is a very good way to build simple lightweight boats. It is a ready made material which does not have to be "manufactured " by yourself as the builder. It is easily formed and most importantly it doesn't have to be "faired", just some careful planing round at the chine joints. It is strong, and if made to Spec.1088 standard is waterproof.
It should be stood as near vertical as possible in a dry, room temperature place, for several days to allow the water content to stabilise at about 12%, and then coated on one side with two coats of thin epoxy and left to dry. The side panels can then be cut out on the floor and butted together with epoxy glue. The gunnels, stringers and chines are then glued and fastened in place, and the butt join straps glued and fastened in place between the horizontal members,(longerons). The frames are cut out with a jigsaw, the raw wood edges are sealed with epoxy and the edging fitted and chamfered. The frames are offered up to the side panels and marked for notches to clear the longerons.

When this is done the sides can be placed facing each other with the epoxy side inward and the middle (biggest) frame can be fitted in place, glued and fastened. The transom and stem piece can be pulled together, glued and fastened after the edges are chamfered to match. A straight batten with one edge on the centreline of the transom is eyeballed to be parallel with the stempiece to ensure the hull is not twisted. The frames can then be glued and fastened into place, starting at the centre, alternately out to the ends. This took us one hour using fast setting epoxy glue and staples. The resulting "Box" can simply be stood on two stools to work on the bottom panels, no strongback needed.
You will need a "Helper" during all this, --if only to provide a second pair of hands to hold things.
With a "Helper" the Bucc 24 took us 482 man/hours to complete the basic boat, over a six week period. It took a further three weeks to fit the boat out, assemble it at the launch site, fit all the spars rigging, equipment etc: and launch. It was a great day.

 

Thanks for that link, It was very interesting, a pity more detailed construction detailed were not included. a 6.5m boat that weighs in at 750kg... Amazing!

Similarly, Roberto Barros' POP 25, can be appropriately described as an IKEA boat, as the bulkheads are constructed with fixing points and other elements already attached to the fore and aft faces of each bulkhead, early in the construction process.

What appeals to me most is the idea that the many things that need to be true in relation to the many other surfaces that are curvaceous and oddly angled, become easy, with a cut and match to already fixed bulkhead points. Even if the hull is not sitting true after turning, you'd still end up with a great result without effort or time consuming measure... check... cut... check... glue in place... oops, methods.

Admittedly it is small monohull, but the building method would still be relevant to a multihull project and obviously fast to construct, with builtin methods to prevent construction mistakes.

An animated GIF and some notes are quite informative about this construction method.

http://www.yachtdesign.com.br/02_ingles/plans/pp25/constr41-2.html

 

This may give you some ideas for a catamaran if you choose the plywood route.

See also this thread
http://www.boatdesign.net/forums/multihulls/21k-30ft-cat-csc30-38737.html

 

I assume you mean build in under 1000 hours rather than in 90 days (as you don't specify the number of workers) But why? is there a new flood coming we should know about?

You also don't say whether you want a sailing boat, a power boat or a house boat. The sailing boat will take longer to build, the quickest is a houseboat followed by an outboard powered power boat

Having said that, I have built two liveaboard sailing catamarans and been sailing in under 1000 hours. The prototype Windsong and the Gypsy. The former I lived on for 5 years.

Both boats had flat panel grp hulls with a gelcoat finish, because I agree with groper that for speed you want to use glass and gelcoat - unless you want a really rough finish in which case epoxy/glass sheet ply with no filling/sanding is faster.

But if you must build in 90 days then you need to work non stop and cannot wait for glue/resin to cure. So I'd suggest aluminium - you don't even need to paint it and within reason you can work outside and in cold/damp conditions.

I write more about simple boats on my website

Richard Woods of Woods Designs

www.sailingcatamarans.com

 

The pictures above posted by Imaginary are not what In had in mind when you say multi hull.

Is it a typo --do you mean 90 hours?

 

I am working on a project right now that is dragging out, I don't want to do it again. I am also not so good at multi-tasking. If I didn't have a day job (or was able to take a few months off) to just focus on one project at a time, I would be so much farther along. Instead I have 4 projects at home, and one will get done next week, but the other 3 will get pushed back into 2013 (hopefully).

It is a motivation thing too. If you see that you are making progress, and that you know in a few weeks it will be out on the water, it is easy to continue to work hard on it. I have no problem working hard, but I need to take a few months off in-between big projects, and that hasn't happened in the past 8 years.

And it will be my midlife crisis project. I don't want to be too old to enjoy it, and I don't want to have too many bills related to renting space and health insurance that would add up if it takes months and months.

It is up in the air. I didn't want my crazy ideas for boat design to get in the way of people explaining what materials to use or what process they implemented. My ideas change pretty frequently, and I'm not sure the testing will validate them or not.

http://www.aviationweek.com/Blogs.a...a7Post%3a558410e8-a76c-460a-94a5-c335599ee4b9

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http://api.ning.com/files/Iyak1H5Us...-6puy8P1komcuGZLnJXd/PlanetSolarsTRANOR1.jpeg

in a cruising type of boat that can handle going from Michigan to Florida (maybe even the Caribbean). But, like I said, I can build a prototype next Summer out of PVC and plywood. I can use an electric motor and my 80W solar panel system & 21Ah LiFePO4 battery to see how it looks, and how it works.

It is hard to say what the length of the boat will be. The interior cabin might be about 20'x10', but there would be some deck space and trampolines out front. If I had to guess it would be in the 25'-35' range. It would also need to fit two kayaks, two bicycles, and a dingy someplace...

Thanks for the info. There was an aluminum boat built in Australia on this site, the link is on my other computer, but it turned out nice. Welding isn't my thing though. I would use it on the bottom of the hulls where it would impact waves to strengthen them however.

 

the word "liveaboard" I think is subjective, I have read about some who have built 12 foot sailboats and spent several years sailing them around the cost of north and south america. Others that have sailed to Hawaii in 16' home built sailboat. So you have to define what you mean by liveaboard.

A small boat is far less costly for materials and time to build. I have the same attention span/motivation problem, I have built some 17 or 18 boats, kayaks and sailing dingys, all were finished in several days or several months at most. they come together fast enough I do not loose interest. I am considering a larger project but I know it will just sit in my garage/shop for years, so I might just find something to buy instead.

You must keep it simple, the fewer parts in the built-up the faster it will go. Fewer parts means less to cut out, less to handle, less seams and joints. Size is also one of the drivers, consider that the surface area goes up with a square of the length times two (you have both inside and outside surface to finish). Each surface has to be gone over by hand some some five or six times (or more depending on construction method). So the time to finish goes up exponentially (times two) as it gets longer. same is true with cost as well. the smallest you can "live" with, the faster it will get built. Also the easier the towing, launch, rig and getting underway, the faster to clean and maintain, etc.

Keep it small, keep it simple, it will come together faster and cheaper.

 

A hard Chines plywood monohull would prob be the only way to go here, I actually had a similar thought myself a couple years ago. Wound up buying an old keelboat and doing a refit, prob took about 60 man hours but by the summer I was sailing and it costed a hell of a lot less than building new would. Truth is, the end product is prob better than an amateur like me could do by himself anyway.

If u must have a multi, home building might make sense only because u won't find a cat or tri big enough to live on for under 100k at the absolute cheapest, and prob 150 is more realistic. In that case, I would build one of these:

 

http://www.thecoastalpassage.com/cheapcat.html

 

Never mind, that link was already posted haha I'm getting slow

 

I would love to build an aluminum hull, but it might take 1000 hours to learn how to tig weld, no?

 

I would define 'liveaboard' as a ship that has a head, holding tank, water supply, has a berth or two, it can generate it's own electricity without a generator, has a food preparation area, some type of refrigeration, and some type of cooking appliance. It is also of a size where you can spend three days on board in a row, and not feel cramped. It has enough space to carry at least 10-14 days worth of supplies for two people.

I have a 13' kayak, and I'm not sure I could handle a sub 20' boat for weeks or months at a time... Especially when I can pick up an existing 30' sailboat for $5,000 a lot of places (I'm not sure how good it would be though, I haven't looked at any in person). The professionally done monohull boats, even at $20-30,000k are better than what I could ever hope to build, plus be in the water the next day even. There is a good chance that I will end up with a inexpensive monohull to weekend sail on and see how I like it before I would start this big of a project. And multihulls with good prices, in good shape, and with good layouts are quite rare.

I do like the modular type of construction process that some boats have. I like it when you can build or buy pieces that go together. I am quite good building in wood, especially with the right tools. I would need a lot of work on fiberglass if I would go that route.