Boat Forum / Building / April 2007

hi jim,
I built a rowing skiff. The power plant was a weed wacker. My design, an
inboard, the propeller shaft went through the hull. picture:
http://users.rcn.com/neptunium/boat/prop.jpg
I constructed the shaft with 3/4" copper pipe like used in plumbing. Inside
the pipe, a 1/4" threaded rod. The engine side of the rod, squared to fit
the motor coupling, the nylon insert from the weed wacker flexible shaft (to
keep the steel rod from bending and vibration or out of round during
operation.) On the prop end of the shaft, a skateboard bearing, then to fix
the bearing a copper coupling soldered snug. This copper coupling has an
internal ring - holds the bearing tight. Then a rubber from a skate board
truck serves as water seal. On the end of the steel rod, an internal washer
and locknut, and on the end a washer and locknut.
I'm just saying you can build your own shaft with some ordinary stuff.
I crafted my propeller from aluminum cans that I melted in a hole in the
ground in my back yard. Using a clay bisque pot for crucible, and hair dryer
for draft fan, and wood for fuel, I melted the aluminum.
First I made a clay prop. Then I made a mold from plaster of paris. It was
all guess work making the prop diameter and the pitch. First prop turned out
too big and too much pitch. If your buying a prop you should have no
problem. These weed wackers are like 2 horse power. A prop for 2 horse
should work. I threaded my prop on center and put a cotter pin to keep it
from unscrewing.
Mine was 2 stroke. And it smoked a lot. I built a muffler and tail pipe but
the smoke followed the boat sometimes. Go with 4 stroke if you have one -
less smoke.
I do think what you want to do is ok. Your idea is great, just remember to
bring paddles with your boat if you get stuck.
greg :)

Per jimhigh66:

AKA "Dragon Tail"?