: Back in 1970 a couple of friends of mine made a small rowboat for
: temporary use on a summer vacation. A form of sand directly on
: the beach, covered with a sheet of plastic, chicken mesh (three
: layers if I remember correctly, sewn together with thin wire and
: folded over a couple of times at the sheer for strength) and
: then concrete, worked into the mesh (the concrete as dry as
: possible to be strong enough). Hull thickness approx. 4-5 mm.
: The result was surprisingly flexible, with a horrible finish and
: not as heavy as feared (I guess 30-35 kg or so for the two meter
: dinghy). A couple of wooden pads with oarlocks were glued on
: with Plastic Padding and a piece of styrofoam was thrown in to
: sit on. It leaked badly but after a coat of cheap house paint
: that was under control. At the end of the summer it was still
: serviceable, and was thought to have deserved a pair of crude
: wooden rails glued in to stabilize the wobbly sheer. It was
: still about, and used the following summer but was then lost.
: Nobody ever admitted having anything to do with the
: disappearance. Despite the obvious shortcomings of the
: quick-and-dirty boatbuilding attempt, I was so impressed with
: the ratio between cost, work and result, that I later build a
: ferro-cement yacht
: http://www.thomassondesign.com/nyheter/maria-kristina-tillbaka-i-sitt-ratta-element
: .
: So why not a temporary concrete kayak?

No reason to not make one in concrete, lots of ferro-cement boats have been built. I just mentioned that I'd want to spend some time experimenting with materials first to find the lightest way to make one and still have it strong enough for use.

Using wire mesh as used on a "conventional" ferrocement boat just seemed to add needless weight for a minimal increase in strength, has to be a better reinforcement material available.

Bill H.