Modern boat made simple, ferrocement flat sides and bottom and top

Take a modern 6 meters boat. Building solution could be that, 6 meters long triangle , flat sides , flat bottom , flat top.All made with 8 milimeters -1/3 inches - thick ferrocement.And you installed twin , 25 degrees right left angle, keels.

They say its possible but boat hits hard every wave.

It could be slower , not comfortable but important thing is owning a boat.

I can lay a 8 mm high female mold on flat ground with filling inside with concrete reinforced with high percentage steel fibers.

I can make all molds in empty place , call the concrete truck , pay 100 dollars and fill the molds.

Wait 5 days and find a forklift and built the boat with gluing and riveting.

And fiberglass the lines connecting.

Mustafa Umut Sarac
Istanbul

 

If you build flat panels, they need to be thicker and heavier than curved ones. However, for 100 dollars, give it a try and see what happens.

 

Buehler designed a 3.5 meters whole curved boat out of 6mm thick concrete. Flicka 20 , 7 meters long, made 15mm thick ferrocement
I think I can find a optimum with 8mm for 4 meters long boat.
It would be very heavy. But extremelly cheap and fast.

What would I do for capsizing ?

I think I can lower the height for 60 centimeters and find a stainless steel mast and make a anti capsizing empty zeppelin to the top.

How much would that boat slower ? If it is slower ?

I am thinking the boat as sleeping bag , no standing etc .

 

The boat will be neither cheap nor fast to build. A good design in plywood would be a better choice if you want fast and cheap. A stainless steel mast, besides being really expensive, will be a lot heavier than a standard aluminum alloy mast. In short, your proposal only makes sense if you want to spend time experimenting with some unusual materials. However, if you want a boat to use, conventional shapes and materials are much more appropriate.

 

Plywood costs , transportation from seller , transport to laser and again come back to you is extremelly expensive. And for that cost you only buy poplar plywood or alike. I cant afford plywood , low quality plywood cant withstand to stress and dangerous. Epoxy is 20 times more expensive than polyester.
Polyester is 60 times more expensive than concrete. And glass fiber 160 times more expensive than concrete.

I am thinking for very very long time , an concrete panel mold from plastic or ply which is shape changeable. You can produce any number of side bottom panel with this. I thought if I place 4 thick steel rod in to each panel , I can weld each panel to other. Other thought is to mold with frames and rivet with very thick steel pieces.

 

I thought ferrocement was applied by trowel

 

What do you mean by laser?
You can't weld ferrocement. The heat will expand the metal and crack the cement. Your system is not good and with steel pieces riveted to cement, corrosion will make it have a short life. Polyester is not 60 times more expensive than concrete. That would mean that you are using about $6000 worth or resin for the boat which can't be right.

 

Epoxy isn't much more expensive than the steel suitable for building the armature for the boat. It ends up being about 1/3 steel. Think of it as a steel boat coated in concrete. This can work okay at 50' and right on up to 200' or more, but it just doesn't work on small craft. It will be far too heavy, and cost of ownership ends up being mostly a matter of weight. A fiberglass boat will be way cheaper in this size over time. The epoxy I use is actually somewhat cheaper than decent boat-building polyester. It's way cheaper than decent house paint. The sort of concrete you use for boats is very tech and fussy, and you can't get it delivered in a truck. You normally machine mix it in many small batches as you plaster the hull. It takes a small crew and a lot of labor. Mixtruck concrete is about a 3 1/2 bag mix. Ferro is an 12-13 bag mix/yd (600kg/M^3 min), and you can't use regular Portland construction cement, and the aggregates have to be super pure, perfectly graded, and not allowed to separate or stratify, so it's best to begin each batch from raw ingredients stored in weather-protected containers. You need to dry and weigh a sample volume of each aggregate each day to compensate for moisture changes and fluff. And you need to be very astute with the pozzolans and plasticizers and retardants, which all interact with one another.

Please read the FAO report on ferro - FAO Investigates Ferro Cement Fishing Craft Laboratory Analysis Construction Methods Service Experience https://archive.org/stream/faoinvestigatesf034702mbp#page/n31/mode/2up

 

Has anyone noticed the OP is from Istanbul? Comparable cost and availability of different materials may differ greatly there from in the States. That doesn't make what he's proposing a good idea, but it might help explain his thinking...

 

This is a bout the 20th Thread started by the OP with radical ideas of how easy it is to build better boats with ferrocement.

Everything that has been proposed so far has been discussed ad infinitum.

I am starting to wonder about the sincerity of the OP's research.

 

It's called obsession

 

Yes. OP seems to be a boat lover/inquisitor, but unwilling to appreciate the realities of cost and seems to be seeking the lowest cost always which is a bad route.

Good boats ain't cheap.
Bad boats ain't cheap.
Boats, generally, ain't cheap.

Once in awhile a good boat is sold for cheap; more often bad boats are sold for cheap.

I took two bad boats to the dump over the years; cost me like 500$ disposal. Two others I burned. I got some parts from all of them and the costs were likely a wash net net or so.

The best thing to do is guidance. You first decide on a boat that suits you best. Sailboat, displacement hull or planing skiff, for example.

You don't desperately seek cheap building materials that would box you into a boat that is buildable, but doesn't meet the requirements. (Gets heavy)

Hope must lead.

Decide what boat you like first. a sailboat, a fishing skiff, a kayak, a canoe

Then build method follows.

There are beautiful, relatively inexpensive, and lovely recreational boats being built in Istanbul. Not with concrete that I have seen.

The concern I have is if you are seeking any boat and not a specific boat. Why?

I need a coffee.

 

A quick google search shows 6mm marine plywood made in Turkey selling for 20 euros.

 

Lot cheaper to build a s&g monocoque than a concrete boat. Sorry if I was unclear.

 

It for the OP that says that plywood in Turkey is very expensive.