Concrete Canvas Junk Voyager - design and assistance

[Magus]

Greetings.

It is my hopeful intention, in the not too far distant future, to move to the coast and start building a sailboat full time.

To that end, I seek assistance of the fine people here of this forum, in advice on how best to navigate these new life waters I have chosen.

Ideally, (emphasis on the ideal, actuality may differ) my idea is to build a 40ft junk rigged sailboat having a concrete hull and timber support/strut/ribbing, made with a hull design loosely based upon that of a Chinese junk, mixed with a traditional 18th century European full keel sailboat. I hope, with this ship, to do mostly solo voyaging and exploration, about the coasts and in open waters. I expect, when complete, to spend a significant amount of time living aboard, either sailing, or anchored off a coastline. And while I expect to be solo most of the time, I also hope to have basic accommodations for at least 5 other people. My budget for this project, presently, is at $10k, and a lot of optimism. But those parameters should only increase over time.

I recently completed my ASA basic keelboat sailing certification, but otherwise I have no experience in this manner of venture besides a large consumption of sailing and boat-building youtube videos. So I'll be relying upon the good people here t

Any and all advice, towards the end of accomplishing this task, would be welcome. Thanks!


About my choice of Materials:

I was inspired mostly by these two Youtube videos:


I figured, if a flexible fabric could be used for a small boat hull, and ferrocrete is a viable large hull material, I might as well mix the two and get the best of both worlds. There are several videos about concrete cloth which I would recommend before making a judgement on it. It also eliminates the failure mode of rust so commonly fear-mongered about ferrocrete hulls. I've also seen several videos of tiny houses where the roof was described as nothing more than a cloth soaked in concrete and draped over the roof frame.

As for how the two materials would work in a marine environment, I expect it would be something similar to concrete laid wooden fence posts. If I design it well, I expect to be able to clear out any rotten wood in the support slot and refit it with only a little bit of joinery knowledge.

About my choice of hull design:

I prefer the look of a Chinese Junk, but did not want to risk a broken rudder, due to the traditional design and figured a full keel would work instead. I also cannot stand the look of the modern pilot house, wanting more flat deck on the front end to walk about. I do like the rear cabins of traditional European square-riggers though, so I wanted to incorporate that as well, as best I practically could.


I will add further details at a later time, and as I refine my plans.

 

[gonzo]

Your budget is about ten times less than what you need for a plain boat. The concrete/timber is a strange combination of materials. I suppose it may be possible to engineer it, at a considerable cost, by an engineer. The term "junk" is pretty generic and mostly describes an eastern asian boat. If your budget is $10k, it will be cheaper and better for you to buy a used 30 foot boat in good condition. Building a 40 footer by yourself will be a two year, full time occupation. That is assuming you have reasonable skills in the trades. An even better idea, buy 21-22 footer and go sailing. If you are still enthusiastic after spending a few days in rough weather, then spend more time and money on a larger boat. Your budget will hardly cover the empty hull. The rental of a space large enough, transportation and launching will take most or all of your available money.

 

[PAR]

Ditto what Gonzo has said. The best advice you could get right now is to beg, borrow and steal rides, on as many sailboats as you possibly can. This will help you develop an SOR for your dream yacht. Given your current experience, you really don't have any rational clue about what you need, want or desire, except possibly the aesthetic portions of the SOR, which frankly are minor considerations in the big picture. Lastly, you should start pricing out, well used, poorly equipped 40' yachts. This will offer an idea of the budget you'll need, just to purchase a well used, worn out yacht, of this class. A new build will be considerably more, unless you have vast experience in yacht construction, materials procurement, a sufficient building space, etc. Also, I'd strongly suggest you reconsider the idea of a concrete hull. You'll find it all but impossible to insure in the USA (with good reason) and it's simply not a very good hull shell material, compaired to the other choices.

 

[Magus]

Gonzo, thank you for your advice and information. I know that the budget is low at the moment, but that's really just the rock bottom. I don't aim to do this tomorrow, and in the meanwhile, I will be getting more money to budget. I hoped also to save money by designing, engineering, and building all or most all of it myself, from scratch. I wasn't aware that such a build would take 2 full years and most of the money on logistics, but then that's why I'm here in the first place, to learn all these things.. and learn it before I start pushing money, parts, and labor around.


The reason I'm choosing to build, rather than buy a used boat (and I have considered that option), is, well, quite frankly, I'm picky with the particulars, but more than that, I also want the full experience, the journey of building and launching a work of my own two hands. I want more than to just sail; I want to inspire others with my work.

The best thing about sourcing advice early though, is I'm not stuck with my initial plans. I can downsize and alter according to what will work best, and that's what I'm hoping I can get the most help with, is refining my ideas, and learning what I'll need to know when I actually get started.


PAR
Thank you also. I would love to source rides of all sorts, but at the moment, I'm not sure that's quite a possibility. At least when it comes to different types of sailboats. I do have a membership with the business I got my ASA certification from, to let me sail their rental boats, but they only have two of the same model, for me to sail on. I expect that after I move down to the coast (I'm currently landlocked, living near a lake), I will have more opportunity to do this. You are right though, in that I have next to no clue about what's what. That's why I'm here; and I'm hoping you and others can help guide me to a good starting off point.

I understand that, generally, a new build is very expensive, but that's part of the reason I determined to build the boat, and out of concrete of all possible materials. I'm not looking for luxury here, actually I'm hoping for a very bare-bones build that I can outfit and improve over time after launching. I'm willing to use a tree and burlap sacks for mast and sails if it makes the build cheaper; along with an interior of little more than a hammock, camp stove and bucket, if need be. That's how low I'm cutting things. As long as she's seaworthy, I can upgrade her as time and materials permit.

Another note about concrete, or ferrocrete. I'm not planning to use mesh and rebar for the concrete like most boats, but rather canvas impregnated with concrete, sewn and layered over the wooden rib framework. This for ease of application, time expediency, and cost.


I appreciate the advice and information, and I expected such discouragement. I'm asking though, how I can make this work, not whether it is advisable to try.

 

[gonzo]

If you want a hobby instead of a boat, that is a journey to take. Since you are going to have to learn engineering, naval architecture and the shipwright's trades, consider adding another five years to the project. Your proposed building technique is a really, really bad idea. Learn some engineering first before coming up with structural designs.

 

[PAR]

You don't appear to have the engineering skills, to remotely consider substituting reinforcement materials in ferro cement construction techniques. In fact it's the wire armature in ferro cement, that makes it a viable consideration in the first place. So, from an engineering standpoint how can you justify canvas as a reinforcement material within concrete? How will this provide the elongation modulus necessary? How do you think this SOF concrete over wood will react with each other, physically, chemically, in the marine environment? You might want to do some small scale tests first, as these two materials don't like each other that much on land, let alone on the water.

It's one thing to consider primitive living and another to engineer something, you'll be further from shore than you can swim back to, let alone ask your loved ones to travel along with you.

Your ideas evolve with experience, so this is your goal now, to get experience. Sign up as rail meat at the local sailing club and do the duty each weekend. Forget about rig types, hull material choices and focus on sailing and listening to other sailors. You'll quickly change your "models" about various things and in the first few years, everything is up for grabs - rigs, hull forms, length, accommodations, materials, literally everything. Don't get stuck on some eloquent remarks in a popular book or two (the junk rig sucks BTW), just stay open minded and acquire an honest bias, based on YOUR experiences. Before you consider any rig, sail one for several hundred miles in all types of weather. You'll probably find, just like most everyone else, that the Bermudian ketch is a much better rig for cruising, which is also why is is predominantly prefered in mid size cruising yachts.

If you want the "experience", build what will become the dinghy to your mother ship, preferably using the same building method the yacht will be. 8' x 3' 6" will do and it'll serve several purposes, the least of which as a tender for the yacht.

 

[gonzo]

I agree. You could wisely use $2000 from your fund and build a sailing dinghy. Yes, that is what it will cost you in materials for building a small sailboat. That is if you don't buy anything fancy. It will put into perspective the magnitude of your project. After you have a few months into building it, the reality will hit you in the head.

 

[tane]

...experiments...

...I guess if someone wants to reinvent the wheel nothing is going to stop him...

 

[FAST FRED]

" I hoped also to save money by designing, engineering, and building all or most all of it myself, from scratch"

Doesn't work that way,

Best you start actual READING , not watching video and understand boat design and construction.

The money and effort you save will help purchase a genuine boat that will function.

"I'm asking though, how I can make this work, not whether it is advisable to try."

To prove it wont work simply create 3sq ft of your canvas concrete hull, and flex it or hit it with a hammer.

Then do the same to a piece of plywood , or a hunk of hull from a scrapped boat.

The interior on any boat takes loads of time and skills , so perhaps you can find a gutted or previously sunk boat to go sailing in with a hammock and sea swing stove.

Good hunting.

 

[Petros]

with a $10,000 budget, the best thing you can do is buy a used sea worthy sail boat and go out sailing. you will get on the water in less than one tenth the time, and one tenth the cost.

After you spend some time sailing and living on the boat, and get some engineering courses under your belt, than you can think about what you want in a boat you will be designing and building.

I have 30 plus years as a professional engineer, been self employed as an engineer for over 20 years, I have also built 25 plus small boats (sailing dingys, canoes and kayaks), and I do not think I would attempt to design my own deep water sailboat.

I am far better educated and experienced than most amateur builders and designers, and there are many things I know I would want in a liveaboard cruiser, but there are many things that I would depend on competent navel architect to do for me.

Because I know enough to know I do not know enough to make a successful design my first attempt. this would allow me to do what I know best, and depend on others to contribute their expertise.

IN the long run it would save time and money to hire the right skills. But first you have to get out on the water and get some time at sea to know if your dream boat will actually as intended, or become your nightmare and tomb.

good luck.

 

[FAST FRED]

After all boat building has been going on for thousands of years, purchasing thousands of years of expertise is far better than a learning curve.

What desirements do you have that you feel only your design can give?

 

[Magus]

Time is irrelevant to me, I'll take as long as necessary, but preferably shorter than longer. I'm not looking for a hobby; I'm looking for a life, as the daily grind is squeezing it all out of me.

I have already said I know I don't yet have all the necessary knowledge to complete this task. And while I may not have all the Specialized knowledge, I am a quick observer, and good at connecting threads that seem entirely unrelated, into something that makes sense. In other words, I would say I have a healthy dose of common sense and logical and analytical thinking, with a significant history of theoretical study.

Some of you have said I need to study, listen to other sailors, and get more experience.. What then do you think I'm doing here, if not that?
What resources, knowledge, and experience do you have that you can offer me to assist in completing my intent? Please share.

It was always my intention to complete some tests before going ahead with everything, which is why I've posted this so very far in advance of actually starting. I'm trying to save time otherwise wasted on failures and mistakes. My unique situation, however, will hinder my effort to produce anything physically significant until I've actually taken the first step and relocated to the coast.

I've edited my first post with my reasoning for material and design choices.

So here's a few basic questions all or any of you could answer, to help me get started:

What rig do you use, and why do you like it?
What is your experience with rigs other than the one you use most?
What advantages/disadvantages have you found of each rig type you have used?
What kind of hull materials do you have experience with building?
What kind of boats (hull type/style) have you built and/or sailed?
What have you found were the advantages/disadvantages of each hull type/material you have sailed or built with?
What are, in your opinion, good proportions for Beam, LOA, Freeboard and Draft?

 

[gonzo]

Research in mostly failures and mistakes. Once in a while there is a good result. If you want to do R&D on a new engineering technique, $10,000 won't even get you started. However, if time is irrelevant, you could spend a few decades and maybe end up with a boat. In general, people approaching project in this manner will find out that most of what they built is of low quality or simply doesn't make sense. That is the reason why there are so many unfinished project rotting and rusting away in boatyards and fields. I started apprenticing as a shipwright at eleven years old. By the time I was in my thirties, my knowledge was reasonably good. Studying engineering took several years of my life; still going at it. The questions you are asking are so general that it would take several thick books to answer them. To start with, you need a budget of at least $300,000 to make an attempt at developing a new building method and material. I work in R&D and have a pretty good idea of costs. Your best route is to find a design you like and pay a naval architect for it. That is their job.

 

[nzboy]

This one is for sale in Canada on website of ferrocement boats for 14k why build?

 

[FAST FRED]

Some of you have said I need to study, listen to other sailors, and get more experience.. What then do you think I'm doing here, if not that?
What resources, knowledge, and experience do you have that you can offer me to assist in completing my intent? Please share.

The collective wisdom of this board which may be a few hundred years of hands on experience sez,

DON'T BOTHER,,GO BUY A BOAT.and enjoy life.

Why do you ask a question if you will not listen to the great advice given?