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Construction - V
Progress Report - Apr. to June 2000
Recently I was able to get
my hands on a demonstration copy of Vacanti's Prolines 98.
Heck, you can even get it yourself at their website.
The demo version does not allow you to save your work,
but I was able to enter the lines of my boat in about an
hour. Once entered, the program gives a 3-D perspective
of the hull (you can do the deck also if you have the
full version) that you can turn and play with like a toy
model. That's nice, but the real meat for me was the
hydrostatic calculations. I put in the ballast (weight
and location of each grouping of ingots), and then
watched the program churn through the convolutions of
slowly tipping the hull over. Now, lots of questions came
up in my mind, like how does the program determine the CG
of the hull without the ballast? But let's not allow the
nitpicking facts get in the way of a good story. Based on
this data, the program concluded that my vessel would
reach its point of no return (capsize) at around 130
degrees. Whoa! That's better than many ocean-going yachts.
Okay, back to reality. A more useful benefit from this
exercise was showing how the hull tips in the water given
a displacement of 1600 lbs. Specifically, the rail (or
gunwale) touches the water at around 40 degrees of heel.
That's pretty far over, by gum. After a few more
experiments the program locked up, probably due to some
internal demo clock so you couldn't design the next
Carnival Princess.
All of this was an interesting
sideline. I plan to conduct my own real life stability
tests as part of the sea trials, but having this in hand
will provide an intellectual comparison.
We'll start off here by showing a picture of the interior again, this time with the lockers
in place (the piece below the elliptical porthole) along
with the head and galley tops glued in. All surfaces have
been coated with epoxy in preparation for a primer coat.
Contrary to most everything else, the bottom of the
lockers are not held in place by a cleat. I had to anchor
them in place with a couple of nails while I applied a
fillet on one side. After that solidified I pulled the
nails and put another fillet on the other side.
Also visible here are fiddles installed on both the head and
galley (shown in the lower left corner of the pic).
Hopefully these will help keep things from flying around
in a seaway. Later I will install several padeyes around
the head hatch so I can tie things down, like a stove or
porta-potti.
Time for the cabin top.
Here's the first sight of my lead ingots, put to good use
to hold down the 1/4-in. plywood until I can get all the
screwholes drilled. Despite the amount of curvature and
having a bit of compound curve near the forward end, the
ply never complained. Warning - this
stuff is 3 ply; the grain of 2 veneers run in the same direction. That
means it will bend easier along one axis than the other.
In this picture the grain of the 2 veneers is fore and
aft.
One thing to be careful of here is making sure
that all surfaces of the ply are snug up against all
supports when you pre-drill the screw-holes. Also, start
at one end and progress to the other. Otherwise you run
the risk of the screw-holes not lining up properly.
And here are both sides
completed, trimmed and sanded clean. The second half was
more challenging because I couldn't use C-clamps on the
center stringer. Instead I had to use 4 or 5 screws. Not
a big problem, just a bit more awkward.
Now I had a choice. I could
either glass the cabintop and then install the
hatchrails, or the other way around. I decided to put on
the hatchrails first, because I prefer to have wood to
wood glue joints wherever possible. Whether this really
makes any difference, I don't know. The only other thing
left on the cabintop will be the handrails, and I'll put
those on after I glass.
After this stage, I had to put
a doubler in the inside aft 12 in. of the cabintop. This
is designed to provide reinforcement for the cleats that
will hold the running rigging. So the question was, how
do I glue a piece of ply on an inside curve without
punching holes in for screws and nails? I came up with
some "stilts" that I could rest against the
furniture inside and force the ply into position. Well, I
guess it's hard to describe without seeing it, but it was
a pretty simple setup.
Through the miracle of time elapse photography, here
we have a sequence of how the cockpit went together.
Any questions? The leftmost
is the cockpit at the time of the previous page. The
middle has the outer cockpit railing, cockpit well sides,
and traveller beam installed. The cockpit seat is also
done, although that's harder to see. The rightmost has
the cockpit coaming complete except for the rail cap, all
cockpit hatches in place but not attached, and the
cockpit floor is done. Notice the hatchboards as well.
There were no surprises here, just a lot of little piece
work. The only tricky part was fitting and glueing the
cockpit floor, which is one continuous piece. Several
steps were required to get the floor ply around the
permanently installed traveller beam.
Here's a closer look at the
cockpit seats. Each hatch has a frame around it to help
seal it from water ingress. Although the aftmost hatch
looks restrictive, it's still big enough to be able to
reach most of the compartment below it. Remember that I
have no limberholes in the bulkheads, so water will have
to be sponged out from each section. The other hatch openings are
big enough to reach everything easily. That comes as a
relief, since I was concerned about having to become a
monkey to retrieve an errant item underway.
The coaming carlin is still overlong after glueing the
outside ply in place. I trimmed it down before glueing
the inside coaming section.
Looking on the other side of
the coaming, here's a closeup of the oar socket. There is
still a 5/8-in thick rail cap to be glued on the top of
the coaming, which is why the block sticks up a little
bit. My intention here is to reinforce the oarlock
location and spread the load over a wider area. Whether
this is enough will become apparent when I actually use them. If I rip them off,
well, I built the boat, so I think I can handle
fabricating another solution.
It's hard to tell here, but the oarlock is installed at a slight down angle. I
drew a diagram of the boat and a set of 9.5 ft. oars to
see what it would look like. Due to the freeboard, it's a
pretty good angle. So I set the socket around 8 degrees
so it would prevent the oars from binding on the oarlocks.
So let's talks decks since we can see some deck next to the coaming. This picture
shows the foredeck after it was glued in place. A butt-block
is glued to the underside to take the next deck section.
You can see primer on the interior. The next deck pieces
I primed and painted the undersides since it would be
more difficult to do it when
they are installed. But there is a hazard with this plan.
After they are glued in place, there is more filleting
done inside. Those fillets, and other missed spots, have
to be primed and painted also. In the process, epoxy,
primer, and paint drips onto the parts already painted.
So I have to go back and repeat the whole process again.
So after doing the starboard side like that, I'm glueing
on the port deck with just an epoxy coating. I'll take
care of all the remaining priming and painting in one
shot.
Speaking of painting, I've pretty much stuck to
my proposed plan on the previous page. According to the
Interlux literature I only needed one coat of primer (yes!).
After 2 coats of the enamel, I think I'll probably need
another coat in certain places to make everything look,
well, truly snazzy.
Before I leave the foredeck, I've received the mast
tube and associated metal pieces from a local machine
shop. I needed the tube to accurately cut the hole in the
deck and the brace near the mast step. Once cut, I was
able to fit everything in place with satisfaction. I
won't permanently install this part until after the deck
is fiberglassed, primed and painted.
And finally, this picture shows 2 things completed--the hatchrails and the whole
starboard deck. I'll say right up front that the fact
that the hatchrails are perfectly parallel is a complete
fluke. Measuring with accuracy on a slowly adjusting
curved surface was hard work. I just did my best and
crossed my fingers.
And the deck? Easy as pie. I used those cut templates that I
described before and they helped tremendously. On the underside I
have glued reinforcement blocks for cleats (the horn variety) and
U-bolts. The U-bolts will be used to tie down a boom tent (an
upgrade that I'll eventually get but I'm planning for it now) or
an occasional fender. I also glued a couple of blocks for
potential stanchions for lifelines. I don't plan to put lifelines
on this boat, but if I'm forced to (at gunpoint), I'll have the
extra strength there.
I can't describe the feeling of satisfaction after putting on
the deck and standing back to admire it. It seems like getting it
fully enclosed is the first step to getting its personality. No
longer is it a random pile of boards cut at strange angles, or a
skeleton with no comfortable way of getting around. It now has a
skin to show the true purpose of its design.
Another thing has happened that is purely an illusion. Before,
it looked ungainly, huge, any moment about to swallow my garage.
Now it looks a lot smaller, a lot more manageable, and the garage
doesn't look so threatened. I'm sure that when I move the boat
outside, it will look vastly smaller, at the launch ramp a small
toy, on the ocean a minute plankton. But it will be my plankton
that I had fun creating.
At press time I'm about to finish the rest of the deck, then
I'll finish the priming and painting of the inside. After that
I'll have no choice but to fiberglass the deck, the cabintop, and
the cockpit. Oh, Boy!
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