(Appeared in June 2000 Flashes)
Cement Lightnings?
Over the phone, it sounded pretty neat. I was talking to a young
civil engineer who was part of a team of students were building a rather
weird canoe.
A concrete canoe.
These young people who will build our future highways and bridges
were supposed to learn how to manipulate the recipe for concrete so it
would float.
These concrete canoes are pretty neat, I was told. The better ones
look just like commercial fiberglass canoes.
This I had to see. And forgive me, but the thought crossed my mind,
"What if you made a sailboat, maybe even a Lightning, out of
concrete?"
Heresy, but I was curious. I had a look at this concrete boat.
And I was far from convinced. It suddenly occurred to me that there
was another reason besides learning about roadbuilding which would
explain why it was civil engineers and not naval architects were making
boats out of cement. More than one reason, really.
It was an ugly craft. It looked like it was made crudely made -- out
of Play-Doh.
They are brittle, fragile vessels. I noticed large cracks in the
boat, even before it was launched. The students were handling it with
utmost care, afraid that a tunk on the tarmac would bust it wide open.
I will not be building any boats, Lightning or otherwise, out of
concrete.
But concrete got me reflecting about that other obstreperous building
material. Fiberglass.
While big boats have been made of reinforced concrete, steel, even
aluminum, with sailing dinghies it seems we come back to the old
face-off between wood and fiberglass. Class rules in most cases have
precluded experimentation, I suppose. I delved into the glass vs. wood
debate a bit last month when I discussed Wooden Boat magazineıs
re-design of the Lightning. I wonder how that boat, glued together with
epoxy, is holding up. Would the epoxy-encapsulated wood resist rot and
prove as maintenance free as a glass boat?
Unfortunately, the magazine sold the boat and lost track of the new
owner. Canıt call him up and ask him how itıs doing.
But others have experimented with new wood building techniques. Mark
Patty of Santa Rosa, California built an epoxy-and-plywood Lightning 15
years ago.
I asked Mark how that boat compared to glass Lightnings.
Unlike Wooden Boat, whose Lightning was built with
conventional frames along a backbone, Mark Patty chose to build his boat
as if it were an airplane. He calls it the "stringer" method,
and his very good how-to book is for sale by ILCA for $10.00
Anyway, instead of building frames and screwing, nailing or gluing
planks or plywood over the frame, Mark built a skeleton resembling the
frame of an airplane over which he placed sections of quarter-inch 5-ply
marine plywood. Because there is a compound curve on the bottom,
plywood sections had to be fairly narrow many pieces bend to shape
easier than one or two big sections. Each piece of wood was coated with
epoxy, and the plywood pieces also were glued with epoxy to the stringer
frame. There are no metal fasteners in his boat.
For want of a better word, Mark calls the technique
"cold-molding," though he admits the term is not quite apt
because the Lightning has a hard chine. Cold-molded boats usually
are soft chine boats, and the entire hull is made of plywood or other
material glued together. Over the plywood, he glued pieces of 3/8-inch
veneer to give the boat a rich, natural look. The veneer also adds to
the overall strength of the boat.
So how did this woody compare to fiberglass boats?
First, says Mark, "It was way stronger than even a plank boat.
By the time youıre done, itıs all one piece. No seams, not a nail, no
steel, no bronze, no staples, nothing left as far as hard
fastenings."
Repair-wise, "You donıt have loose screws and pop rivets to
deal with."
"Fixing the wood boat is a heck of a lot easier than fixing a
fiberglass boat. If somebody rakes off your rubrail, you smooth it out
and paste on another piece. You get your plane out and plane the thing
down and put another piece in and fair it all back together."
In terms of upkeep, ³I was racing in salt water. When I finished,
Iıd rinse the boat off and hit the bar."
"From a maintenance standpoint, I donıt think youıre giving
anything away to a fiberglass boat. In some ways, youıre going to beat
them, because the wood boat is not going to gain weight and the
fiberglass core will suck up water. When my boat was built, we had
40 pounds of lead in it. Towards the end, I think I maybe took off 10
pounds of lead. It gained 10 pounds in 15 years. Not too many
fiberglass boats are going to do as well as that."
He and his crew were rough on the deck, and every couple years heıd
re-varnish it. "A new coat of varnish and it looked like
new." Several years after he launched it, the deck began to
show wear, so he painted it white.
