| |
From a Bare
Hull: Deck Beams
|
Main Foredeck Beams
Because
of the very simple and open design of the deck on this boat, nearly all of
the deck beams were to be short pieces, with only a few full-width beams
used in the design. Full width beams were in fact limited to the
foredeck area (forward of the cabin trunk) and the extreme after part of
the boat, aft of the cockpit. Since the cockpit and cabin sizes and
shapes were largely to be determined visually as I went along (with some
reference from my basic construction drawing), I decided to begin by
building and installing the foredeck beams, the longest beams in the
boat. Daily, for seven days, I laminated up a beam a day (the first
one being my beam mold).
|
With
the necessary deck beams laminated and planed smooth, I arranged the six
beams in the proper locations along the sheerline, sitting on top of the
edge of the hull. (I did the beam layout during the sheer
clamp placement.) Even though the beams looked a little funny
sitting on top of the hull, it did give an impression of what the finished
deck would look like.
Now
all I had to do was trim the ends of each beam to fit in the space between
the hull sides, supported at the proper height by the sheer clamp.
In theory, this seemed simple enough, but I soon found that it was far
more complex than anticipated--a fact that was further complicated by the
fact that I had to learn as I went. |
It
took me several hours, all told, to mark and fit the first deck beam--the
smallest one all the way forward. I chose this one to start since it
was the smallest one, so if I made an irreversible mistake it would be
easier (and less wasteful) to relaminate a replacement. However, I
learned a great deal from my first foray into beam fitting, and in about
another hour's time I managed to mark and fit two additional beams, so I
was obviously getting the hang of it.
Rather
than digress into a detailed description of the fitting process, I would
choose to refer you to the myriad texts on the subject. The book I
have that has been of great use during several portions of this project is
How
to Build a Wooden Boat, by David C. (Bud) McIntosh. Suffice
it to say that each beam, particularly those near the more dramatic curves
of the bow, required a number of cuts in order to fit properly:
angle cuts on each end, to match both the curvature of the sheer towards
the stem as well as the flare of the hull, and birds' mouth cuts on the
undersides of the beams so that the beams rest flush on the sheer clamp
and at the appropriate height--which, in this case, meant about 3/4"
below the height of the sheer to account for the 2-layer plywood decking. |
Getting
the first beam to fit was a challenge for several reasons. First, I
made the mistake of cutting the miter cuts at the end before marking the
rest of the cuts on the beam, so I ran into trouble holding the beam in
the proper position on the highly-angled (in two directions) sheer clamp
at that location. And getting the cuts just right took many trips up
and down off the staging for fine-tuning, partly because I marked the beam
in a less-than-ideal manner in the first place. After an hour or so
of this frustration, I consulted McIntosh (which, dumbly, I had neglected
to do beforehand) and discovered a much easier and more accurate method of
marking the beams for cutting. Coupled with my experience on fitting
the first beam, the new technique made all the difference in the world,
and I managed to cut the next two beams in a greatly reduced time.
Note
that a more extreme amount of the first two beams had to be removed in
order to fit at the proper height around the sheer clamp. Because of
the difficulty in bending the clamp down to the proper marks at the most
forward extreme, it ended up slightly higher than ideal. Had the
beams featured a longer span, where the full strength of the laminations
would be needed, I would have modified the clamp accordingly, or taken
whatever steps were necessary in order to ensure that it bent to the
proper line, but in this case I didn't worry about it. Starting with
the third beam from the bow, the clamp was located at its proper marks, so
each additional beam would have only a small amount cut from the
bottom in order to fit properly. |
Later,
I finished fitting the full-width beams that support the foredeck.
The aftermost of these beams corresponds with the forward edge of the
carlin that will define and support the cabin trunk (see
the drawing at the top of this page);
the curved carlin will be tangent to this final deck beam once it is
installed. With the exception of one or two full-width beams at the
stern of the boat, aft of the cockpit, all remaining beams were to be
shorter lengths, spanning the distance between the hull and the
yet-to-be-installed carlines. |
Once
I got the hang of the measuring and marking process, fitting the beams
proceeded smoothly. I made a measuring error on the third beam from
the bow and ended up cutting it short by about an inch on each end, so I
was forced to laminate a new blank and start over. I found myself
staring at the marks on the beam that I had made six days earlier, the
last time I had been at the boat, and things simply didn't click for me,
which led to the error in cutting. Once I realized what the mistake
I made had been, I marked and cut the remaining three beams without
further incident or problem.
|
With
the first six deck beams roughed in, the ultimate appearance of the deck
began to become more clear. There were a number of small jobs that I
needed to complete before installing the beams permanently, so I left them
loosely in place while I began other tasks. Before final
installation, the exposed beams will require additional detailing,
including sanding and a bead or roundover detail on the bottom edges.
Before anyone writes, please note that in
the photo to the right, you will see what appear to be huge gaps between
the beams and the sheer clamp. While there is some play, the reason
the gaps look big is because I marked around the edges of all the beams
with a black marker to help locate them later, during final installation,
and the marker also left marks on the beams themselves, creating the
photographic illusion of a gaping opening. Click
here to continue>
|
|