http://s190.photobucket.com/albums/z211 ... der%20Mod/
The tiller was shaped in a T out of a 2x4 pressure treated block. Hard wood would look better but would be harder to shape. There's a SS bolt through the tip of the thumb tiller and the block, but just a SS screw through the back of the block and the thick part of the tiller. "Goop" was used to build up support between the block and the tiller. Goop works e to wwell on plastic and wood. It hardens to a hard plastic consistency and gives excellent adhesion. There are two pad eyes on either side of the block for the tiller extension, which is a four foot wooden dowel - it has an eye bolt screwed into the tip and opened up just enough to slide into the pad eye. The opening is just enough so that you have to hold the stick vertically to slide it into the pad eye but not enough for the stick to fall out of the pad eye in the operation position.
The extension connection provides good mobility, but not too much play. I tried other methods suggested, but there was too much play for confident use in higher winds. Haven't tried the extension on the water yet, but the tiller works very well. You don't have to lean as far forward and it's much more comfortable to be able to wrap your hand around it than to have all the work done by your thumb. It remedies my number one objection (maybe the only one) to the boat's operation.