ferrocement boats

how to build ferrocement boats.
What you do is build a wooden frame in the shape of the boat you want, tack on several layers of chicken wire and metal rods . . . and then cement over all your mistakes (you'll have a lot more leeway with this process than if you were working with wood or fiberglass). Once the reinforced or "ferro" cement sets up, you'll have a seaworthy hull that's both dirt-cheap and virtually maintenance-free. And, if you keep the thickness of the troweled-on pour of cement down to less than an inch (which provides plenty of strength), the shell will weigh about the same as a similar hull constructed of wood.
The ferrocement process seems ideally suited for that large boat you never thought you could afford. Pool your spare change and weekends with a few friends and you can build the hull of a 36-foot fishing boat in 700 man-hours for a materials cost of less than a grand! Or bring in a 50-foot work boat hull—with deck and bulkheads—for less than 2,000 man-hours and about $4,000.

Yes, it seems certain that ferrocement boats are here to stay . . . still, a few words of caution are in order before you dash off to "pour your own".
Many experts in the field advise against using the process on very small designs—say an 18-foot boat—because the thin-hulled craft that result are not (in the experts' opinion) seaworthy. We know of several people who've constructed exactly such designs, however, and they have no complaint. Then again, they weren't amateurs either.
It should also be noted—even when constructing a bigger ferroconcrete craft—that the final cementing: plays a very critical part in determining the ultimate strength of the vessel. If you can find the cash to hire a professional plasterer to do the job, by all means do so.