styrofoam sail boat idea, have questions.

[cenkaetaya]

Hi, i have had this idea of making a boat with either 50 gallon plastic drums or styofoam for floatation. The most difficult part was designing the idea of how to make the hulls, considering there may be some leakage. I thought if the grooves perfectly fit the styrofoam, even if the outer shell leaked a little, there would not be much space for the water to enter.

The inner shell which houses the strofoam would be made of some sort of plastic / wood hybrid to avoid rot in the underside. The interior and top of the boat would be built separately, on top of this chassi.

This chassi would allow the boat to be unsinkable and easy to repair. If the outer hull layer was damaged, it could be replaced with ease since the boat would always float. The outer hull would basically be there to improve speed of the boat.

a large kiel would be used to balance out the boat since it would be much lighter then other boats its size

let me know what you think

the idea borrows from that JUNK boat and the Plastiki, and some previous home made boats / rafts

also what type of materials would be good for the inner hull, to house the styrofoam, some sort of plastic.... such as of that plastiki boat maybe?

[gonzo]

It is a bad idea. You'll end up with a complicated expensive and weak structure.

[cenkaetaya]

yes, but the boat would be unsinkable which would make it safer.

I was thinking you could not even cover the outer styrofoam, but use some sort of hard (tarp) or extra strong plastic material and wrap the outside of the boat.

The inside of the boat would be essentially a box shape, with Styrofoam in a boat shape perfectly fitting around it.

The wrap around the foam would provide for more speed, and the internal compartment would be completely sealed.

I think the structure would be very strong, and styrofoam if overly damaged would be easy to repair

I was thinking maybe the cabin area could be lowered into the boat, and that way easier to work on. The exterior would be an essential housing for a cabin and all the works of the boat.

[gonzo]

No, some of the pieces may be unsinkable. That is the same as a wooden or cored boat.

[cenkaetaya]

well what about those other boats...such as the plastiki

your answers are rather short....

I mean, this sounds like it should work, have a styrofoam hull that is tightened down by some sort of exterior mesh. The boat itself would be incredibly strong.

Say use 1/3 of a hight of a shipping container, and surround bottom and sides with the foam, it will also be reinforced with wooden ribs....

[gonzo]

It would not be strong. The balast keel would have nothing to attach to, neither the rig. If you put a steel box in the middle and the foam breaks off, it will sink. Might as well make a steel boat and save money and time. How does it sound like it should work. Show some structural and displacement numbers at least.

Originally Posted by cenkaetaya

your answers are rather short....
..

Long enough, I think.

It just does not work. It is one of the weakest ways to build a structure. What else is worth a word?

[G8R]

What are your plans on holding it all together? sorry I see you're thinking of using a tarp. forget a 42', try a 8' or 10' and go from there.

[PAR]

I disagree with the premise that it can't work, though you surely have some major engineering issues to sort out.

This type of structure is being used currently. All foam core structures need to meet certain physical qualifications to be suitable as a core material. There are foams that will do this.

The short answer is, yes, you can do this, but unfortunately your understanding of the engineering to make this possible is limited, likely nonexistent, considering how highly engineered selecting and developing these types of methods are. Therefore a better method for you would be to use an existing set of plans for a foam core hull or to hire a NA familiar with these types of structures. This would be especially true of a 42'+ vessel.

Lastly, the method of building a hull can be clever and inexpensive, but the hull build effort is only about 10 to 15% of the total amount needed on a 42'+ vessel, so you savings isn't as big as you might think.

[souljour2000]

I'd build a model of the thing...maybe 1/25th scale or so...with your materials it may have to be bigger...then look at it...make some notes...then put it in a closet for two-three months...........Meanwhile... read some more threads in here..alot more threads....threads about stability/materials/ dirty sailor jokes etc....Then build another model...afterall.... your first one was probably generously flawed...then look at that one....take a few weeks and hold it in your hand in your free time and ponder it's qualities...then take notes...in your mind and on paper...then back in the closet with that one...make sure and throw the first one away or burn it....let life go by for another month or two...in this time read again...read books at the library... and then read more of what the guys in here talk about regarding stability/ materials and their fallibility or strengths...ease of certain builds/processes vs. others....then take the new model out of the closet and look at it again...think about....etc...if it still seems like a good idea..then build your boat...if it's a piece of floating crap then you will have learned alot....if it's not a piece of floating crap but a piece of floating garbage...screw it...you still learned alot..if it's close to what you envisioned then you may have a real future in yacht design...I don't mean to sound skeptical...just trying to be practical..an idea like this may stew around your brain for years...my point is there may be fairly cheap/painless ways to figure out whether it is a good idea.... or to let it go from your gray matter and move onto something else..the process I just described might be one kind of fast track to helping you avoid wasted time on a pipe-dream...or get going faster on what may be a viable design...It's not a failure because you learned something and spent your time on an experiment with your brain that did not involve small tiny plastic bags of white crystals or which TV crime drama has forensics specialists with bigger boobs...the latter is not the worst activity actually but messing with boats is ultimately more life-expansive...My honest two cent take? Well... it sounds expensive and a bit like something you could only use in a labor day cardboard boat regatta from a strength standpoint...but it should float...though alot of things float...

[cenkaetaya]

Thanks for the input.

I redesigned the idea a little,

Basically i thought of starting with the interior, The interior would be a long brick type of shape (shaped somewhat the shape of the boat) This Enclosure would be water proof and and basically be the HULL>

Around this interior, would be made the half circular ridges, basically going the entire length.

The styrofoam would be PERFECTLY places into all of these grooves with almost no empty space. THen the outsisde will be (not waterproof) sealed by light, hard plastic to protect the styrofoam from damage or easy scraping.

To HOLD the entire thing, extra well, i thought of this:

a combination of
1- smooth yet very strong plastic matherial
2- layer of net
3 - tough matieral
4 - another layer of a net
5 - final plastic that touches the styrofoam covered by sheets.


^^^^

This whole contraption would be pulled and tightened along the bottom of the boat. Along the sides, and the back.


SO: Basically the TRUE hull of the boat is the wall between the interior, and hte area where the foam is. The rest of the hull is actually to help it float / take damage.


Picture: Shows how the foam will be around the interior

the stuff sticking out the sides like wings are solar pannels

[gonzo]

Besides being heavy, expensive to build and rather weak, what are the other advantages?

[cenkaetaya]

why do you think it would really be that weak? I mean it will have a very strong structure, and the weight can be cut down it think.

The advantages would be:

1 a unique design, with bonuses such as deck space, and custom designed for the people who would travel on it.
2 have it be safe so that it wont sink
3 easy to repair

thats about it, It shouldnt cost all that much either. If you subtract the cost of the engine / electronics....

like 30-50k?


THE IDEA behind this boat; or these boat designs is:

///.. To make a cheap custom boat that can travel around the world for a few years, to have it be as safe as possible, and easy to repair. It also needs to house 3-5 people and be semi comfortable.


I have a few different ideas, but i think this method above will sacrifice on speed the least ---> the mesh that is along the bottom, can be made of different things, almost like a snake skin for the boat.

[gonzo]

Unique is not and advantage.
How does it not sink if it breaks up?
Where is the ease of repair?
Not one of your claims is substantiated. Also, there are not structural details. For example: keel and rigging attachments. Another problem would be through hull fittings.

[souljour2000]

Unless you can address some of the things Gonzo mentioned..I think this type of construction would be difficult with many unforeseen problems that will only appear during it's contruction and likely leave you with an expensive floating barge...a garbage barge at worst...at best you may end up with a decent houseboat/floating office of sorts...but one that could only be used in a marina or in extremely protected area... might not be a bad idea...that way you've worked out the bugs but still can salvage something useful before designing something that should ever leave these types of protected waters...