Several new holes

As Aussie Andrew observed, I left the story in suspense in the last post, having drilled most of the way through the deadwood, and not knowing exactly where the drill bit would emerge.  Now I know.  The good news is that my initial bore was not terrible (i.e., it didn't come out through the aft bulkhead, nor through the garboard strake) but the bad news is that it was about 7/8 of an inch to starboard when it came up through  the keel.  There were several options regarding fixing this.

Option 1:  Accept the situation, enlarge to hole to the desired width, and mount the engine to the starboard side of center in line with the shaft bore. This would have worked, since I made my engine beds wide, and the engine is a very small proportion of the total displacement, but it would have looked strange and amateurish (Even though I am very much an amateur, I don't need to display that fact any more than is obvious and unavoidable.)  

Option 2: Use a boring bar to gradually enlarge the hole in the direction needed, i.e., to port.  This solution is limited by the total diameter of the final bore.  In this case, I needed to move the center of the bore 7/8 inch to port. The initial bore was 5/8 inch, and the final bore would be no more than 1 1/4 inch.  That would not give me enough space to recenter the bore and still end up with a round hole.  

Option 3: Plug the hole with a dowel and start over.  This solution had some appeal, except that I had no reason to believe that re-boring the hole would necessarily  produce a better result.  I thought all my measurements and jigs were spot on, but obviously I had gone off somewhere.  Perhaps a second try would be worse.

Option 4: John Brady, my first boatbuilding mentor and the current CEO of the Independence Seaport Museum offered what he has referred to as a Rube Goldberg solution to a Rube Goldberg problem.  

John Brady, ISM CEO and my boatbuilding mentor.  Thank you, John.

He suggested taking a hardwood dowel the same diameter and length as the bore, and cutting a tapered kerf running from the center of the dowel at the deep end to zero at the shallow end.

John's clever solution to precisely reroute a bore 

Then, glue the dowel into the bore, deep end aft with the kerf facing the direction we wanted to move the bore, i.e., to port.  Next, rebore the hole from the same starting place (now the center of the dowel) and the bit would follow the kerf and move the bore half the diameter of the dowel to port. Repeat the process as many times as needed to shift the forward end of the bore to the centerline while leaving the aft end in the same spot.

I tried it, not really believing it would work, and was amazed that the bore exited the keel exactly next to the edge of the dowel.  I made up another identical dowel, followed exactly the same procedure, filling the new bore, and redrilled again.  We gained another half dowel width, and were close enough to the center line to make any additional corrections using a boring bar.

In the photo below you can see the centered bore as well as the cut off ends of the two dowels used to straighten the line.

1/2 inch boring bar inserted in the realigned pilot

The boring bar was made of a 1/2 inch diameter 6 foot mild steel rod.  I drilled a 3/16 inch hole through the rod to accept a tool steel cutter, and another hole for a set screw to hold the cutter in place.  I am waiting for the tool steel bar to arrive so I can make the cutter, so I moved on to other projects.

The boring bar awaits its cutter.

The next order of business was the installation of the traveler which, compared to the prop shaft, was absolutely painless.  I epoxied 2 white oak backer blocks to the underside of the aft deck, drilled through, and fastened my threaded and bent bronze rod through.  I'll remove it to weld bronze stops onto it at either end of the horizontal section, but for now it is in place and looking pretty good.

The traveler is set in place.

Now I am a plumber.  I began working on the raw water intake side of the engine system, with the expert advice of Jeff Huffenberger, the Director of Workshop on the Water at the Independence Seaport Museum, and my host for this phase of construction.  Working with Jeff's suggestions, I first located the raw water strainer at a convenient and accessible spot on the cabin bulkhead, below the water line.  Then, I made sure that I could get a smooth and gentle hose connection from it's output side to the engine intake.  Jeff suggested a shut off valve on the intake side of the raw water filter to facilitate shutoff for cleaning in an emergency, in addition to the seacock at the raw water intake through hull fitting, and I made the investment.

My pile of plumbing stuff

Raw water filter assembly mounted on bulkhead, low as possible.

I positioned the through hull at a point as low as possible below the waterline but in an easily accessible location that would allow an easy connection of to the strainer assembly.  For me, this was the center of the second plank on the starboard side, alongside the aft end of the engine.  I made an oak backer block on which to mount the seacock.  This will be epoxied to the plank. Finally, I drilled the hole through the hull.  

Oh no!  Not another hole in the bottom!

The seacock in positon, but not yet fastened.

I think I'll be plumbing for the next week or so, and hopefully will then return to boring the shaft bore.