Saturday, November 23, 2013

Steaming and Drilling

A big space has been cleared at the front of the shop for students in the ongoing SAILOR Program.  Every Wednesday, the floor is filled with white painted plywood lofting boards, as the kids learn to transfer boat designs from plans to full size patterns.  The program is still gearing up, and more groups are scheduled to start soon.  

Volunteers, meanwhile, continue to work on the Beetle Cat restoration.  We are still engaging in "tag team" frame replacement, with each group of volunteers taking over from the team that worked the previous day.  Slowly but surely, the new frames are being bent and fastened.  We are well over half way in the process.

Some more oak frames-to-be steam in preparation for bending.
Bob M. contemplates his next move.
A whole line of newly bent and installed frames.
The "Holiday Boat" has left the shop and now sits in the ISM lobby as part of the seasonal decorations.  Fittingly, before being put on display, she got a fresh coat of green topside paint, applied by volunteers.

The holiday boat, a Whitehall, ready to go on display.
Charles and friends, most notably Bob F., continue the mechanical installation on the Oughtred Grey Seal.  The 1200 pound lead ballast is completely installed -- bedded, bolted in place, faired, and painted.

Ballast faired into skeg using thickened epoxy which was later sanded smooth.
The ballast is complete -- sanded and painted.

Work has turned to the engine installation.  First step was hoisting the engine, a rebuilt Yanmar 1GM, into position on the engine bearings.

The engine is lowered into position below the cockpit sole.
  Once the engine was set in its approximate location, the location and slope of the prop shaft needed to be determined.  This was accomplished by mounting a board along the centerline of the boat, using a plumb line to transfer the slope of the engine bearers to that board, and extending the slope aft.  The drill bit was then positioned at the same angle, and at the height appropriate to drill the  36 inch deep shaft hole.

Slope of engine bearers and height of engine coupling is drawn on board at centerline of hull.
Guide blocks were mounted to supports at the appropriate height to begin drilling.  The drill bit -- a 24 inch long 5/8 inch auger bit -- was inserted into the guide, and drilling began.  Because one of the major problems in drilling deep, deep holes like this is that the drill bit moves off center because of density variations in the wood, the tip of the auger had to be ground off, creating a "barefoot" auger bit.  This configuration stays much truer, but cuts very much slower.

The slope and height have been transferred to the drilling guides.

Once the drill has gone a foot and a half or so into the wood, the guides can be safely removed, and drilling can proceed.  The last foot of drilling will require the addition of a drill bit extender.

Charles drilling -- the bit is about 15 inches in at this point.


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