Day

150

Cutting for stern tube, bending portlite frames
Above isn't really related to what we did today, but it's definately boat related! A 70' luff on this sail we purchased ( for a song ) off of Ebay is a bit too long for our humble cruiser so we were looking at ways it could be cut down with a minimum of grief. Neither of us have done much more than a patch on a sail so we may hand this over to a professional to deal with. I have read "The Sailmakers Apprentice" and now have an understanding of the complexities of a sail ( which makes me even more afraid haha! ) but the lack of space to deal with such a large sail is a real problem. To make a sail, one requires a lofting floor, ie large, flat, no wind, rain, snow etc. and experience.
As I am to be the designated "sailstress" I made a small jib for our 21' flatbottom and it held together, shaped, and balanced great. From that to this, though, is too big a jump. Maybe my next sail will be, say, a stormsail ( hehe then I just have to avoid storms! )
 
Gena plazzing for the stern tube
Anyway, enough said..

Gena got an early start on the keel this morning as by the time I came outside there was a gaping hole pierced into the back of our pretty keel. This is so the engine can be connected to the prop.
I hate engines even more now!
The holes previously cut through each frame were enlarged enough to accept the 3 1/2" tube. As the holes won't be absolutely perfectly aligned, Gena has commissioned me to make some small plates with a "perfect" 3 1/2" circle cut out, then split in two so they can be put on bottom first.

 
 
Da big Prop!!

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....just kidding!!



Frames for aft portlights bent

The prop was trial fit after the shaft was put in...

Everything fits!! Yay! Bravo to Osbourn Propellers and W M Dafoe! ( Who machined the shaft. )
We tryed using the engine fan for a prop then realised it was going anti-clockwise so it wouldn't work ( haha!) Besides, the prop we had custom made is made of "Superstron" not aluminum and plastic web.

The shaft is made from Aquamet 22 which is better than stainless because it is stronger. It was a real juggling act between bearing sizes available, engine RPM, shaft RPM, prop diameter ( 22" ) and shaft diameter. Gena researched this for months, and it looks like we will have great performance with minimal cavitation.

Another "almost" was a feathering prop, one that folds back when not in use so to minimize drag, but the price was a bit too high for our budget.

We found out that with our transmission, a Hurth ZF Marine 25a, free wheeling isn't a problem thus reducing drag. It's still a debate between us because a free wheeling prop means more wear on the bearings. Ours are of cutless variety.

We actually only require one cutless bearing ( as we found out after buying two! ) because of the strength of the shaft. There ( supposedly ) won't be enough wobble between the engine and the prop to be of concern.

This is a relief because we were worried about how much movement there would be in the engine mounts. I guess it's all by gosh and by golly.

Meanwhile, as Gena did the tube preparation, I bent some frames for the 6 aft portlights. (<< left ) I know that's a lot of windows, I do like to have lots of light!
These were much easier as the angle up the frame is outward, not a rain catcher like the cabinsides, so they could be all one piece.

Next weekend is the labour day long weekend so I plan to get all 6 installed!

Well, that was about it for today. The tube is in place ready to be welded up, and the portlites will be ready to put in by next weekend. Over the week ( evenings ) we may have the chance to weld in the tube, but we really want to realign the engine one last time to be certain everything is ok.

 

Day 150: 9 hours - made portlight frames and plates, welded in mounting plates for stern tube etc


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