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 magazine's 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. Can't call him up and ask him how it's 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 you're done, it's all one piece. No seams, not a nail, no steel, no bronze, no staples, nothing left as far as hard fastenings."

Repair-wise, "You don't 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, "I was racing in salt water. When I finished, I'd rinse the boat off and hit the bar."

"From a maintenance standpoint, I don't think you¹re giving anything away to a fiberglass boat. In some ways, you¹re 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 he'd 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.  "What do you do with a fiberglass boat when it starts getting chalky? When a woody gets ratty, you paint it."

Where trailer bunks sometimes create soft spots in glass bottoms, Patty never had that problem.

Once in 15 years, he flipped the boat, sanded the bottom and re-varnished it with linear polyurethane.

What about speed? It was a competitive boat, but not as fast as his best glass boat. Why? Mark experimented with the shape of the bottom, hoping for a hull that would really scoot downwind.

"It wasn't as fast as my fiberglass boat, but it could have been if I hadn¹t screwed with it," he says.

I learned about wood on glass confrontations. As we slowly maneuvered onto our hoist, I made one of those little navigational errors which caused the bow of my woody to bump my neighbor's glass hull.

Bump?

My stem punched a hole that cost me $100 to have fixed.

Mark Patty noticed a reluctance of glass boat sailors to come close to his boat. It was a great advantage on the starting line and near marks. And it wasn¹t fear of being clobbered.

"They didn¹t want to hurt the pretty boat."

Joel Thurtell
11803 Priscilla Lane
Plymouth, MI 48170
1-734-454-1890 1-734-454-4666

thurtelljh@aol.com