alu sailboat buliding

[zeyang]

Originally Posted by maarty

You do know then, that many boats have ended up on the rocks because they couldn't sail close to the wind.

And back to welding: I don't think you should weld the hull fully from the outside first. I think you should install the stations inside the hull first, to minimize distortion, and maximize strength. Instead of wooden stations they could have been metal. It would have save a lot of work.

yes. lee shore is no fun. Ill see how the lugrig works and test the ability to sail closer to the wind. If its total mess i switch back to gaffrig.

Reason to weld first and put in frames afterwards is to avoid starve horse look. (if any) due to laps (stringers) the boat is pretty stiff already so im not sure if starvehorse will be a problem after all.
I could have started with alu-frames from beginning but i was not so experienced to take that risk. Ive seend a few starvehorse boats and they look really ugly.

zeyang.

[maarty]

I see what you mean with the starved horse look; good point! I see our timezones are overlapping.

[zeyang]

some pics from last days. plank 8 will be on tonight :-)

zeyang

[minner]

keep us "posted" on the progress

[zeyang]

Using mask when grinding alu. Im tired of the alu-taste when eating dinner :-)

zeyang

[llamafur]

how many feet/miles of tig welding are going into this boat?

[zeyang]

havent calculate amount of tig/mig welding yet but close to 1000 meter of welding with MIG i think.

sofar spent 1112.5 hours on this project.

Foundation for the boathouse: 150 hours
Boathouse construction: 249 hours
Making drawing on CAD for the boat:92 hours
Making templates for boat in wood: 185 hours
Making wood-battens for planking: 56 hours
Welding the keel, bow and stern: 56 hours
lapstrake1: 40.5 hours
lapstrake2: 71.5 hours
lapstrake3: 29.5 hours
lapstrake4: 33.5 hours
lapstrake5: 36 hours
lapstrake6: 41 hours
lapstrake7: 40.5
lapstrake8: 32
-------------------------
sum: 1112.5

[llamafur]

wow, this is going to be one cool boat.

[oxy moron]

posting a pic of yourself, blond hair etc al, and with a name like "zeyzang" sort of begs for the question of, what are you doing in china?

no matter how reversi-racist, or reverse-reverse-racist i might seem, I still feel betrayed :P i was expecting some skinny chinese guy, perhaps with thick glasses (perhaps, as a result of all the time it took learning English) who is just super-geeky and wanted, no matter what, to build an aluminum boat.

sorry there's nothing i can contribute to boat building nor aluminum welding... just wanna point out that i'm either a racist, a reverse-racist, or a reverse-reverse-reverse-racist LOL

[zeyang]

Originally Posted by oxy moron

posting a pic of yourself, blond hair etc al, and with a name like "zeyzang" sort of begs for the question of, what are you doing in china?

no matter how reversi-racist, or reverse-reverse-racist i might seem, I still feel betrayed :P i was expecting some skinny chinese guy, perhaps with thick glasses (perhaps, as a result of all the time it took learning English) who is just super-geeky and wanted, no matter what, to build an aluminum boat.

sorry there's nothing i can contribute to boat building nor aluminum welding... just wanna point out that i'm either a racist, a reverse-racist, or a reverse-reverse-reverse-racist LOL

You mean i should look more like this? :-)
Im on of the 洋鬼子 (foreign ghost) who has been working in middle kingdom. :-)

There is a saying: give a chinese a sailboat and you will never see him again.
So there are extremely few sailboats inside china.

zeyang

[Powerstroked]

I love that old WW2 propaganda.

[oxy moron]

洋鬼子 is actually a short for 西洋鬼子.
西洋 is west ocean, literally, but it means "the west" (europe, america).
鬼子 you're right, it means ghost literally, however, when it is used after describing someone's place of origin, or color, it is pretty close to "bastard". for example, if someone were to translate "The N" word into chinese, it would be "黑鬼子"
that can be loosely translate as "black dude" or "black guy" but it means N!^^&*

there is a chance that 洋鬼子 is being used onto you as a term of endearment. i hope thats what it is. be suspicious, the chinese are a very sneaky bunch.

[zeyang]

Originally Posted by oxy moron

洋鬼子 is actually a short for 西洋鬼子.
西洋 is west ocean, literally, but it means "the west" (europe, america).
鬼子 you're right, it means ghost literally, however, when it is used after describing someone's place of origin, or color, it is pretty close to "bastard". for example, if someone were to translate "The N" word into chinese, it would be "黑鬼子"
that can be loosely translate as "black dude" or "black guy" but it means N!^^&*

there is a chance that 洋鬼子 is being used onto you as a term of endearment. i hope thats what it is. be suspicious, the chinese are a very sneaky bunch.

After 2 years back and forth to China im just scratching the surface of the culture and have both bad and extremely good experiences.
China will always facinate me in good and bad ways, but the girls over there are just amazing. hehe. I think they use the word "foreign devil" just for fun. usually its just plain laowai which im getting used to. they shout laowai after you on streets all the time.

..and boy it will be cool to sail along the coast of china from north all the way to the south.

zeyang

[zeyang]

there started to be a 1 inch gap between the woodframe and the plank in bow so i had to fasten it to the frame temporarly. this is one of the reason i have choose not to put in frames first. let the hull correct itself first then install permanent frames.



zeyang

[zeyang]

hi
never tried this before.
i took my small camera and walked around the boat. its just a test but at least you see the boat from the side and from top live :-)

You Tube

You Tube

zeyang

[zeyang]

Hi
Here is an article i found in a book named "From my Old Boatshop" a compilation of many of Weston Farmers writings in magazines before and after War. A little old but i think the article is still quite good reading.
I especially like the high quality work of that sailboat in the picture. Quite a few of those old american boatbuilders could really handle alloy.



Marine Aluminum by Weston Farmer.

Aluminum as a material for the building of one-of-a-kind hulls hasn't
seen much reporting from those who have had experience with
it. Feed-back from the field of usage has been slight.

Since this scribe has designed and has had built a number of large and
expensively equipped yachts in aluminum,

I think it might be worth-while to report how the metal has worked out
in service. What follows is nothing deep just wheelhouse gab as we sag
along out to sea. I think aluminum is tomorrow's material, and it is
here today, right now. There'll be some diehards who will raise an
eyebrow and install a facial question mark when I say this. For them,
I have a parable to relate. It may serve to adjust their thinking.

Up on Mount Ararat when Noah was building the Ark, there was an old
sheik hanging over Noah's fence telling the Master Mariner just how to
build her. This sheik, whose name was Alotabul, knew all about ships
(of the desert, that is), for he'd just sailed his camel through a
sand-storm and knew that if Noah wanted to make any speed with his tub
he'd better put legs on her, with great big feet, and teach the Ark to
trot. But Noah crossed up the sheik. His ark worked just fine, and
safely delivered enough of Adam's sons and Eve's daughters to start
today's apple stampede. You see, Alotabul didn't know a darned thing
about rain.

Noah's descendants, being professionals, are still in argument as to
what makes a good boat, but never waver about building them of the
best stuff obtainable. Wind and wave and wild skies over are forces
for which they have the respect that comes from experience. Where life
is at stake, the best is demanded. On the other hand, descendants of
Alotabul — who seem to be getting more numerous — are still telling
the sons of Noah just how to do things. Now, I'm a descendant of
Noah. All of Noah's progeny are professionals; they know something
about rain, and water, and wood, and fastenings, and know how to work
with them. Their big trouble is that good boatbuilding wood is getting
scarce and very dear. Decent fastenings cost $10 a gross, and a stout
boat, even in nominal sizes, drinks up thousands of fastenings. What
is more, boatbuilding as a guild trade is dying out.

Good boatbuilding is slow boatbuilding. Much search has gone into ways
to cut costs, knock down building time, make the job amenable to
simpler skills. Hence the search for easier ways to close in
hulls. For multiple manufactured units, plastics have been
adapted. This stuff is a chemical ester, a super-cooled liquid in
solid state which is amorphous in character, fracturing like glass or
ice unless reinforced with tension strands of some fabric, such as
spun glass or other fiber. Plastics are expensive, and are heavy. They
do have the advantage of being build-able in female molds by
fractionally skilled labor, but to get a one-off hull, two boats must
be built: the mold itself, and then the hull lay-up.

The old idea of reinforced concrete is another method of closing in
hulls. It has burgeoned at the end of every war during the period o
inflation; it appeals to builders who understand plastering; it is
time-consuming as to the making of the armature; and is over
two-and-a-half times as heavy as wood, only 10 percent less expensive,
and greatly penalizes speed.

The ideal closure would be a light material that is at home in salt
water, as strong as steel or nearly so, could be worked with the usual
woodworking machinery, wouldn't need an ocean of fastenings, and would
allow skill to be quickly built up in its use and application.

Such a material is aluminum. It has 10 times the impact-absorbing
capacity of steel. It weighs only a third as much. It is as light as
wood in boats up to 30 feet in length, and much lighter from that
length on up. An aluminum plate 1/4 inch thick has the shock/impact
strength of 3-inch fir planking; it is, in this 1/4-inch thickness,
abundantly strong enough to plate up to 80 feet in length. It does not
corrode or rust as steel does. It is easier to flip around a shop
manually because it is light. It is the most weldable of metals. Welds
of 90 to 95 percent of plate strength are usual; in steel, 75 to 85
percent of plate strength is more nearly the norm.

Aluminum has had much metallurgical development in recent years, since
the days of the old cast-aluminum cook pots you knew. Alloyed without
copper, in marine usage, its life is indefinite. A boat built of it
usually will be miles faster than a wood or steel counterpart.

Aluminum boats can be built in most any boatshop that has been used to
building in wood, because the same hand tools will work it; you'll
need a welder and some compressed air for chipping, but that is about
all, unless you want to go in for boiled-egg shapes, in which case a
hydraulic bumping press will give you that capacity.

The skilled wood boatbuilder learns to handle this stuff, aluminum, in
one or two boats, developing the same amazing skill with it he now has
in wood. The aluminum weld is its own fastening; a builder won't be
draining the gold reserves at Fort Knox buying fastenings—weld
fastening is inherent in the technique.

Once a skill is developed comparable to that which the builder
possesses in wood, he will find himself closing in hulls in one third
to one half the time needed to bring a wooden hull to the same
condition. In this respect a boatbuilder overtakes the slightly higher
raw material cost of the metal. This "cost" is a chimera, anyway, and
amounts to only pennies: the quotations I have worked with in writing
this chapter place steel in 1971 at 16 to 17 cents a pound. Aluminum
cost, at the same time, was 55 cents a pound. Horrors? Not a bit of
it! See here:

It takes three pounds of steel to cover as much area as one pound of
aluminum, generally. Three pounds of steel at 17 cents equals a tab of
51 cents. The same area in aluminum is 55 cents. For four cents a
square foot premium, you get practically indefinite hull life, miles
more speed, quicker building time than in steel, and a much more
amenable hull-shaping metal.

Where baulks in this proposition are offered, you will find them
coming from a builder whose experience and skills are oriented to
either steel, or wood, or plastic. I happen to have worked in all
mediums. I know the stuff both from designing in all and from having
my hands feed my head the knowledge of the materials. I think my
statement about aluminum is fair and justified.

Any naval architect who has designed a lot of motor yachts, out of the
nature of things, works with and for a good many very wealthy
men. These fellows all have one trait in common: they know values and
the meaning of money, and are hounds for detail in getting a buck's
worth. This smart money has been going for aluminum for more than 15
years. The whipped cream on top of the wedding cake for these owners
has been the simple umbrella of aluminum advantages: low maintenance
problems, greater speed by miles, controllable electrolytic problems,
great tankage capacity and hence much higher cruising range, and the
highest resale value to be found in any material. This has been the
history of ownership in the aluminum motor and sailing yacht field.

The Burger Boat Co., of Manitowoc, Wisconsin, is the leader in
building aluminum motor yachts in the luxury field. In the early
1970s, it was turning out about eight or nine boats a year in the
$200,000 to $900,000 range and had a two-year backlog of owners
waiting for their boats. Burger, as a company, since abandoning wood
and steel in favor of aluminum, has built over one mile of these craft
in overall length. Their joinerwork and finish in general are very
high.

Another bunch of Wisconsin Dutchmen operate a crackerjack
boat-building plant at Palmer Johnson Inc. in Sturgeon Bay,
Wisconsin. This is the best tooled yard I know about, and the Sturgeon
Bay skills in plating are never so evident as here. They use sawn-out
frames, which hold their shape, and can plate a hull of complex shape
to the smoothness of a boiled egg—but then, Sturgeon Bay is unique.

There are three shipbuilding and boatbuilding yards in this
en-chanting small town at the base of the Green Bay thumb on your
map. Out of a population of about 7,000 people, nearly every kid who
graduates from high school starts in one or the other of these
yards. Nearly everybody knows how to toss plates at a hull. You may
see a man delivering your laundry one day and find him doing
complicated loft work the next. Half the bartenders in town are ace
joiner men. So it is little wonder that Palmer Johnson, or Peterson
Builders, or the Sturgeon Bay plant of the Bay Shipbuilding Co. can do
an eggshell plating job.

A scene in the bustling erecting shed of Palmer Johnson, Inc., of
Sturgeon Bay, Wisconsin, as Robert C. Borwell's Misty is nearing
completion from plans by the author. Photo courtesy of Palmer Johnson,
Inc., which specializes in aluminum luxury yachts and state-of-the-art
sailing yachts.

<picture>


I have been in a number of other yards specializing in aluminum. From
them I have walked away with one potent observation: it is a mistake
for a boatbuilder to go at aluminum as though he were building in
wood, substituting aluminum for the usual wood stringers, clamps, and
all. He will use twice as much metal as needed. His first boat should
be built to well-prepared plans for aluminum. In such cases, the
resale value of the boat will be high, because most boats in aluminum
have been designed by crack naval architects who know skin-stressed
engineering and who have aesthetic sense.

But that isn't the sole reason for owner preference. Aluminum does not
rust as does iron or steel, staining everything brown or red. Any
corrosion that eventually can be spotted in scuffed, bright areas,
usually will have a light powder, whitish, that can be dusted away
with a whisk broom, or will develop the dark oxide coating aluminum
takes on if left unpainted. This aluminum oxide, or "aluminum rust" if
you will, has the same chemical composition as carborundum. It is
therefore extremely hard and durable. Many commercial vessels do not
bother to paint, relying on the blackish oxide to form. This same
oxide is hard enough to form cutting edges on the extruded reel blades
of some golf course greens mowers, and is induced by unplating in an
electrolytic bath, termed "anodizing."

Usually, one paint job in four or five years is all that aluminum
needs in yacht service. The method of preparing the aluminum skin for
painting is simple. It is best, and usually cheapest, to close up all
hull openings with tough plastic sheet, wheel the hull into the yard,
and sand blast the bright mill finish off. Some welding "welts" or
swellings always occur on the outboard face of the hull plate; these
are easily scuffed flush with a disc sander using proper carborundum
grit.

I have frequently heard builders of wooden boats (who lean to
Alotabul's camp) scoff at this small investment of labor. Fudge and
fantods! They do not stop to think of the countersinking and plugging
needed in wood to bury a fastening. When closed in, the aluminum hull
is oneweldment, stiff as a casting; a wooden boat is never any better
than, nor any stronger than, the pins with which she is pegged
together. 'Jevver think of that?

After the hull has been sand blasted, usually some sort of chemical
anodizing is provided. There is a preparation called Alodine which
does this chemically, leaving the hull looking a puky
yellow-green. Then an epoxy paint is applied, with such minor amounts
of smoothing grouting as may be needed (a well-plated hull needs only
touch-ups) in an epoxy cement. The epoxy will stick to the aluminum
like a mortgage fancier sticks to his interest rates. The epoxy will
hold vinyl paints, which aluminum will not, and you proceed to finish
off the hull as you would an ordinary boat, observing one simple rule:
around aluminum do not use any paint with copper in it. The
copper-aluminum electrolytic chain in salt water or salt air plates
the copper at the expense of aluminum.

Aluminum manufacturers and processors discovered that what destroyed
early aluminum products in salt environment was the copper in early
alloys. As a result, all present-day marine aluminum is, instead,
alloyed with magnesium and sometimes silicon to give aluminum its
"at-homeness" with salt water. Copper does well by itself as a plating
material, but in salt water, aluminum and copper quarrel.

This brings up the interesting information that aluminum is not only
eminently weldable, but is alloyed in a number of systems, each of
which will give the user emphasis on the qualities he desires: it can
be heat treated, strain hardened, welded by impact, by sound, by
pressure if need be, but usually by what is called MIG welding or TIG
welding, of which more in a moment. If a man knows anything about
wrought iron, aluminum pretty much has the same traits.

The classification of these alloys is interesting, and useful to
know. The system of nomenclature adopted by all makers of aluminum
starts out with 1, and three digits thereafter.

The 1 and 3 lowercase x's series denotes 99 percent aluminum
purity. If there is copper in the alloy, the number will start
2xxx. The manganese series is 3xxx, the silicon series is 4xxx, the
magnesium series (marine usage) is the 5xxx band. The 6xxx series
(used in extrusions) is magnesium and silicon. Zinc starts at 7xxx,
and there is a wildcat group of special-usage formulae that is denoted
by 8xxx.

Thus, in 5052-H36 aluminum plate, the first digit identified the
magnesium (copper free) alloy system, the last two digits 52 identify
the alloy or proportions, the internal digit zero would indicate any
modification of the original alloy's purity limits. The H denotes
strain hardened metal, the 3 denotes the type of hardening and the 6
denotes the temper. Once he becomes familiar with the nomenclature, a
shop man can know exactly what is in his hands as he works with it.

Any of the aluminum makers of this country will supply technical data
about all of this. Reynolds Aluminum, Kaiser Aluminum, Harvey
Aluminum, and Aluminum Corporation of America all gladly supply such
information. One extremely excellent handbook on the subject was
supplied me early in the game by Carl W. Leveau, an old confrere of
mine, who was Kaiser's•field man and a naval architect himself.

A letter of inquiry to the Kaiser Aluminum and Sales Inc. at Kaiser
Center, Oakland, Calif. 94604, will bring information on this book, a
Kaiser "house publication" called Welding. It is a honey, and
describes MIG and TIG welding in abundant detail.

MIG stands for Metal, Inert Gas. The term doesn't need to throw
anybody. Any high school kid can learn the welding theory and skill
needed to produce reliable 90 percent welds with a MIG welding outfit.

In the MIG method of welding, aluminum wire is fed through a tool, a
gun, that looks a little like a Colt .45 pistol. To the butt of this
"gun" is led a series of lines looking like a ganglia of hoses. One
contains the aluminum welding wire, fed into the electric arc at a
speed which is the operator's option; another set of "lines" is the
cooling water for the gun. This is a small stream, re-circulated by
the pump on the welding generator which, taking 110-volt or 220-volt
mainline juice, converts it by regeneration into DC voltage and
amperage.

The wire forms the contact for the arc, and is fed as it melts. This
wire is of carefully controlled alloying, usually from 1/16 inch to
3/32 inch in diameter, calculated to have a melting point at the fuse
point of the metal in the plate, and a recalescence or solidifying
point slightly below, so that the puddling metal cools last, absorbing
in its puddling the cooling contraction. (As an aside, a 72-foot
aluminum yacht such as is shown in my plans here will use about 900
pounds of this wire.)

The inert gas, argon, used in the MIG system is fed from a tank
through a hose around the flame of the arc through holes in the barrel
of the welding gun at very low pressure, 2 to 3 pounds. Its function
is important: it forms a jacket to exclude air, the oxygen in which,
combining with the molten aluminum, would form aluminum oxide. Of the
same chemical composition as carborundum, this stuff renders a weld
brittle. With argon, and no formation of oxide, the weld is tough.

TIG welding signifies Tungsten and Inert Gas. This method is some-what
like oxy-acetylene procedure, except that a tungsten electrode
provides the heat of arc. Extraneous metal, as with oxy-acetylene, is
puddled into the weld. Inert gas is of course used. TIG welding is
generally used on large blocks of metal. Most all aluminum boatshop
welding is done by the MIG method.

Aluminum has about ten times the impact-absorbing capacity of steel. A
collision with a sharp rock that would puncture a steel shell, or
shatter so friable a material as reinforced concrete, will produce
only a large dent in aluminum. I have had actual experience with this.

Once, when I was aboard an aluminum motor yacht running at moderate
speed up a channel, the bottom toggled against a lodged, up-ended
deadhead pile. The whole 40-ton vessel gave a mighty lurch to port,
then proceeded along unruffled. But the skipper turned white; he
checked down and headed for the canal bank. There was no need to.

Engine room inspection showed that between the 1/4-inch by 3-inch
frames, spaced on 15-inch centers, at the turn of the bilge in an
un-tanked portion of the engine room, there was a pillow in the
1/4-inch aluminum hull plate about the size of the upper crown on a
Derby hat. This was subsequently cut out with a sabre saw at the next
haul-out, and a new flat was welded in.

Had the vessel been of steel in comparable tensile strength—strength,
mind you, not thickness—the plate would have fractured, probably
capturing the deadhead and admitting worrisome water. The accident
proved to me that aluminum has the property of absorbing the kind of
shocks which the producers of aluminum claim it has.

Aluminum marine alloys do have strength, comparable in some sheet
forms to mild steel. A loading figure I have used in skin-strength
calculations is 29,000 psi tensile, which is generally the most highly
stressed condition. This allows a factor of safety of about 4, using
1/4-inch hull topside plating in up to 80-foot hull length. This may
sound like a tin-can skin to those used to thinking of planking in
wood, but it is about equivalent in shock/impact capacity to 3 inches
of fir planking thickness.

As to girder plate strength, this 1/4-inch plate size, held on 15- to
16-inch frame centers, is abundant. Jet airplanes, with many times the
G loads, which build up with much more violent rapidity, use
skin-stressed air frames with plating of a few thousandths of an inch.

Take a look at the framing plan here for a 72-foot aluminum motor
yacht. This is the Palmer Johnson stock, standard 72-footer, powerable
with up to 1,000 hp in twin V-12 Detroit Diesels for sustained
cruising at 20 mph. This hull, bare as shown, with her tanks
comprising a series of boxes in her bottom, is strong enough to be
elevated by a hydraulic jack at her center of gravity and, balanced
there, to show no deflection or strain. How do I know? She has the
same 3 inches by 6 inches by .500 inch extruded aluminum keel,
5/16-inch plate from skeg to turn of bilge, and the same 1/4-inch
topside as a 77-footer that once got this accidental treatment.

That unbelievable demonstration of the strength of an aluminum hull
occurred as a result of a comedy of errors about ten years ago when I
was working at Burger's yard in Manitowoc. The 77-footer, an aluminum
hull I had been engineering, had been completely closed in—hull,
decks, tanks, but no deckhouse—when the occasion arose to settle the
matter of the weight, and more important, the center of gravity—CG—of
this vessel. I'd been getting some static from a few descendants of
the desert sheik, and wanted to know.

Mr. Eli Gunnell, one of the owners and the engineering brain in that
yard, who is a great good guy and wonderful fellow to work with, had
agreed that when this hull went to the joiner and fitting out shop,
he'd hang the hull in the big yard crane to give me a fix on the CG.

In the event, communications broke down, and the yard rigger pulled
the outfit right past the crane, around in back of the plating shed
like an ant pulling a shoe box. He wheeled the hull shell into place
with his truck and crew in the outfitting shop.

Too late for my test! I told Eli that if he didn't give a darn, I sure
wasn't going to worry. She'd float where she floated, and that would
be that!

Next morning I met Eli in the administration building. He had a wide
grin on his face. He had come down early, had cut the wheeling dollies
away from the hull to which they had been welded, and with a crew had
chocked the hull in place. Then, thinking he was well forward of my
calculated CG (which he was by about a foot), he placed a 45-ton
hydraulic jack under the keel. This was an ordinary Big Truck jack
with a palm about the size of a man's shoe heel.

Getting under the hull on his hands and knees, operating the jack and
watching the bow rise a foot off the blocking, the better to get some
timbers under the keel, he turned around, squatting, to see how the
other end was resting on the aft chocks.

To Eli's stunned alarm the stern end was above the aft chocks the same
height as the bow. The entire 28,000-odd pounds of aluminum yacht
shell was resting placidly a foot in the air on a jack palm no larger
than the palm of your hand. By sheer accident he had placed the jack
at the real center of gravity.

"I got to hell outa dere! Fast," was Eli's chuckling comment, adding,
"I'd like to see any wooden hull you could do that with!"

As he gingerly bled the jack, lowering the hull, both ends kissed the
chocks at the same instant. This proved there had been no distortion,
no evident deflection. I report this at some length because it
actually happened, proving the strength in aluminum I would not have,
until then, believed.

It may be of value to note here for other naval architects that the
true, or real, CG of a metal hull always in practice is a shade
forward of the drawn, or expanded, CG. I also found by weighing this
vessel with a system of beams and scale readings Eli rigged up for me
that she was 7 percent heavier than my calculation. Later I discovered
on another boat that the plate thickness was running 7 percent heavier
by caliper than the handbook thickness weight given.

Aluminum, like all metals, is sold by the pound, not by plate size as
is plywood. Toward the end of any mill rolling run, the rolls allow
thicker metal through. The stuff is sold by weight and the vendor
makes out.

As to the well-known propensity of metal hulls to be a shade down in
the bow, I discovered by this test that there is more actual metal in
the flam and flare forward than plate expansion shows. If you expand
girths, you absolutely should expand lengths, too, to get the proper
weight and the CG of the skin. If you will add 7 percent to handbook
plate weight, and move your calculated CG forward 1/60 of the
water-line length, you'll come out about right. In fact, on the money,
because you will also have corrected for the built-in 5 percent error
in Simpson's rule, which is not dead accurate, because it favors the
"fat" end of the displacement curve by 5 percent.

Little pounds here, added to little pounds there, loom large at the
polls on launching day when a vote is taken on your sharpness by a
peek at the draft marks.

I can hear some descendants of Alotabul saying, "We never have any
trouble. We keep throwing in a factor to correct it." This is bul
spelled with two L's. I say to these sheiks, you'd better not forget
to multiply your expanded plating area by two either. There are two
sides to a boat. Port and starboard.

On one boat, 40 years ago, I forgot this. The ensuing launching was a
thing of beauty for anyone who had it in for me. The hull went down,
down, down. Half an hour later, in the town's railroad station, I was
shopping for a ticket to nowhere. It proved beyond my meager
means. With a kindly wave of his hand, the station agent extended me
the travel facilities of the entire railroad, at the same time
graciously warning me not to climb aboard any rolling stock. Multiply
by two!

Aluminum boats are faster. There is on record the case, completely
factual, of a stock steel cruiser the normal speed of which was nine
knots. When built in aluminum, the same hull cruised at 17, and topped
out at 20. There had been some modification of line, but aluminum was
the main difference, because the hull, weighing only a third of steel,
did not have to lug around the equivalent of two more hulls in weight.

Now this brings aluminum squarely into the framework of plain horse
sense for commercial boats. Forget the dollar picture I've painted for
luxury yachts. That includes luxurious furnishings. It does not apply
to working boats. If you can go faster, you have more at-sea time, or
faster delivery to market. To put it in other terms, you can carry a
lot more load with lower power, eating less out of your purse—a whole
lot less, in most cases.

An aluminum workboat may get banged around a lot, just as a wooden one
will. But she won't get dozy, nor need annual spring nursing, or as
much maintenance as a wooden boat.

This story started out to be a gab session in the wheelhouse. I'll
have to cut it short; there is more, much more—the subject is
dendritic, like the roots of a tree—tap roots, feeder roots, hair
roots of information beyond number. I don't pose as knowing very
much—I'm just reporting my experience with the metal. It has been good
to excellent.

There are a few wet cigar butts on top of the wedding cake:
electrolysis — some, but not much, just different. There is the
question of electrics and what to watch for, and sewage and how to
handle it, and the wonderful fuel tankage you can get with lowered
weight and great metacentric placement.

And the tale of how barnacles just love that bright spot in aluminum,
and how you can knock 'em off like popcorn with a jolt of 220 volts,
tickling their little feet until Pa Barnacle calls to Ma, "Hey, Mabel,
what's that sizzle underfoot? This whole neighborhood has gone to
hell. I'm leaving!"

But that'll all have to wait for another wheelhouse watch, Mates. Just
open the wheelhouse door to windward, there, and let a little breeze
into this feisty atmosphere. Before I go, I'm telling you how to
handle Alotabul XXXVI if he gets to knocking aluminum.

The short yarn has to do with old Tom Day, founding editor of Rudder,
who suffered no fools gladly. Some contributor to Rudder, many years
ago, had dumped a manuscript on the Old Man's desk concerning the
then-building new Cup defender. This story claimed inside knowledge
that the new boat would be a world-beater because, on her 75-foot
waterline, she would spread 14,000 square feet of sail. Day calculated
the main boom would have to extend 40 feet abaft the taffrail to
spread this canvas. The thought gave him the flydaddlin' fantods.

Now Tom Day was used to accepting his devoirs of respect—not
piquantly, as a maiden courted, nor stolidly as a horse accepts hay,
but regally in concordance with Nature's own plan, as a rose ingests
the dew fore-ordained for its refreshment. To be asked to swallow the
"expert's" statement about 14,000 square feet of sail as being fact
put him beyond jumping on his hat or sailing an inkwell out the
window.

Did he sit down to his old Oliver sidewinder typewriter and start,
"D%xs@J@HN-YuoyY"? He did not.

He calmed himself, wiped the froth from his mouth, and with admirably
restrained rage wrote and published to all his readers the lines I
will use to the fence watchers on Mount Ararat when Noah builds his
next Ark. They will be criticizing Noah for building her in
aluminum. My text for that Day will come from the Tom of his Day:

"If some of you people will go to a mirror you will see a long tubular
object rising above your collar. On this will be a round object
covered with hair on top; this is your head, and inside under the
crown is what we call brains. These brains are given to you to use,
and one of their principal uses is to think. Many of you don't think;
perhaps you don't know how. If you did you would not ask some of the
questions you do or believe the absurd and exaggerated statements you
hear . . . Think, think, think!"

There's a lesson there. If you're not inclined to accept aluminum,
don't knock it or listen to the descendants of Alotabul. Think!

Just ask why the smart money has been going to aluminum. And lean
toward Noah's camp; in years to come, a lot of guys are going to be
left behind on Mount Ararat because a lot of Noah's boys are gaining
on 'em. With that, I leave you till the next chapter.

[zeyang]

wow. what happened to Palmer Johnson mentioned in the article???
yes, the seems to have moved their building to Europe. (France, UK, Norway)

zeyang.

[Shadill]

zeyang, you are one crazy sob, you must have all the patience in the world, amazing work, hope you finish it

[zeyang]

Originally Posted by Shadill

zeyang, you are one crazy sob, you must have all the patience in the world, amazing work, hope you finish it

thanks, I also hope :-)
I just have to reach the point of no return as soon as possible, then after that its very hard to stop. There are so many half finished boats around. :-)

zeyang

[zeyang]

Boatbuilding just gooble up money as soon as I earn them i figured out.

I have this book steel away from 1986 and my intention is to manage to beat the prices of building in that book. Not easy. i whish i was building a boat in 1986, but hey, back then i was way too young to think about anything but girls :-)

Here is a rough budget sofar. (prices are in chinese RMB) This is very optimistic lowend prices and some are not verified yet. i cant think too much about this else i will get sleepless nights about all the money worries :-)

hull/frames/bulkhead: 8mm, 3168 kg x 36.60 rmb/kg = 116'K
deck: 6mm plate. 600 kg x 36.60 = 22'K
stainless water/dieseltanks 144kg stainless (25rmb/kg) = 4'k
ballast 5 tonn (5rmb/kg) 30'k
weldingrods = 30'k ?
gas (500 litre/200bar) 40rmb/litre = 20'k
sails 110sqm = 10'k
wood mast 20 meter = 3'k
running rig = 3'k?
standing rig = 3'k?
sabb engine = 6'k
insulationmats 150 sqm = 5'k
all rest of interior = 30'k
SUM: approx 300'K (around 50K USD)

stuff like windwane, ham/vhf-radios, maps for the world, safety equipments,anchors, etc i have from before so its not in the budget.

this is basically what it cost to homebuild a 40' in 1986 according to the steel away. I hope i manage the same.


zeyang

[rode2rouen]

There's a reason boats are referred to as, "A hole in the water you throw money into."

This is a great thread, Zeyang!
I'm looking forward to the launch!


Rex

[zeyang]

Originally Posted by rode2rouen

There's a reason boats are referred to as, "A hole in the water you throw money into."

This is a great thread, Zeyang!
I'm looking forward to the launch!


Rex

Thanks, dont hold your breath though, its a long journey :-)

[zeyang]

Just finished drawing the original rig for the boat just to see how big sail i need to construct. (seems around 105 m2 totally)

[zeyang]

got some help the other day. even a girl with interest in sailing (and welding)
quite good actually, consider she has never done any tig-alloy welding before.

zeyang

[Joker11]

Oh snap!
Sounds like love!
Does she like Jack and Coke?
Then it would be on!