Saturday, November 19, 2011

Can you believe

the wonderful fall weather? Sheez I've pissed away a few weeks of prime boat building time. Kickin' myself for that. Today I couldn't let the good weather slip by anymore and got back out to the shed. Temps inside were a nice 50+ degs F. Not too bad. If you keep moving, which I did, it's comfortable to work.

What I decided to do today was install the bow thruster tube. First challenge was to draw a straight line down the exact middle of a tube. A quick visit to Google brought me to this trick.

Pretty slick eh?

Second task was inside the boat locating the ideal spot for the tube. Instructions say it should be at least 100 mm (4") below the waterline. Ideally it should be 150 mm (it's a 150mm tube). The instructions also say it, the tube, should be no less than 100 mm from the bottom of the boat. The tube also has to be longer than 50 cm from side to side on the shortest (bottom) side. That presents me with a bit of a space issue.

Using my laser level and measuring from Frame A I located the water line and then drew out the parallel lines for 100 mm, 150 mm and 100 mm from the bottom. I had to compromise and move the tub up 25mm (1 in) so that it would end up the minimum 100 mmm from the waterline. I drew a base line and drilled two parallel holes to set my initial spot.

To draw the hole, which on an curved and inclined surface like the upside down hull of a boat you need to make up a device that'll follow the circumferance of a circle and also move along the contours. It looks something like this.

With this tool I could easily draw out the hole for the tube. The first position I chose the hole was pretty elongated due to the slope and curve of the hull.

I moved the centering hole 3" forward of my original position and drew another hole for the tube. This was much better. A quick run around the holes with the Jig Saw and they were ready for the tube initial fitting.

Using the template for the thruster housing I cut the holes with the tube on the bench. Much easier this way.

Another couple if fittings and I was ready to trim the ends. I marked the outside of the tub where it'd be cut off then put it back in the vice.

You have to use a High Speed Steel jig saw blade on this stuff. It wore the teeth right off of a plain wood blade in about 3' of cut! :-)

Last fitting for today. I'll probably glue it into place tomorrow if the weather permits.

Carry on.