Whatever floats your boat!

Alternatively entitled, “1001 Uses for Old Taekwondo Boards, Use #1”

Our son, like every other child in his Taekwondo class (so I hear), has an under-bed full of these boards. The sheer joy derived from breaking them evidently grants the boards immunity from ever being discarded. This leaves us with a lot of boards which, incidentally, float.

Materials for Propeller Raft:

• Lightweight wood, such as balsa wood, or if you happen to be so lucky, board-breaking boards from Martial Arts class.
• Straightedge, such as a ruler. We used the edge of an envelope. ‘Cuz we’re flexible like that.
• Propeller – ours came from the Party store, and is the type you’d find for 5/$1.00 at the dollar store.
• Rubber bands
• Glue
• Screw Eye/ Eye bolt
• Pocket knife, exacto knife… something sharp but non-lethal.
• Straw

Cutting a groove for the propeller in both sides of the wood (we used the straight edge to make, well, a straight edge for the groove):

After Experiment #1 (aka Friction, or, Will the propeller shaft move more smoothly inside the wooden groove, or inside a straw? Straw, totally.), gluing a straw into the wooden groove:

Missing steps include (and not necessarily in this order):

• Insert a screw eye into the end of one of the wood bits. If you look closely, you can see the screw eye underneath the straw in the above picture.
• Loop a rubber band through the screw eye.
• Glue, and when the glue completely fails to hold, rubber band the two bits of wood together such that the straw cannot come loose.
• Insert propeller shaft into straw

Here, Andrew puts the rubber band around the propeller blade:

Twists, and then lets go:

And to the tub, where we try for experiment #2 (or, Which will go faster, the raft with a truck, or without a truck?), and find out that Murphy’s Law ALWAYS applies to experiments (it was very difficult for Boo to wind the propeller and balance the truck at the same time). Lucky kid, I didn’t learn that lesson till grad school.