Back to the Backbone...

The rabbet is the boat.

That was what Bertram had told me, when I visited his shop in Port Townsend last summer, and while slightly exaggerated, I knew that, fundamentally, it was true. No other single component of the ship is as long, or needs to be as perfect as the groove that runs the length of the backbone from stemhead to sternpost. The rabbet is the joint into which every single plank of the hull will interface at least twice. Backbone timbers being large and irreplaceable, cutting the rabbet is something that must be done right the first time. Mess up badly, and your proverbial goose is cooked.

And so, as the weather grew warm again in springtime, I put my ambition to get started cutting out frames on hold, and returned to the backbone that lay waiting for me in the yard behind my house's back deck. There was no point in delaying the inevitable - if I were to proceed, this had to happen. Having spent the past two years working up to this point, however, I was just a little bit nervous.

As is usual when critical events in the construction are about to happen, I asked Dad if he would be willing to drive down and supervise. I find that having an extra set of eyes around is helpful in the "recognizing stupid mistakes before they happen" department, and with a cut as important as this one, I wasn't about to leave anything to chance. The fact that March 27 was Easter Sunday was entirely lost on me until he arrived and started cracking jokes about "the Easter rabbet". Good old Dad!

The plan was simple. I would cut into the backbone with a circular saw set 1/4" shallower than the final rabbet depth, and 1/4" inside the actual line. Since the backbone had already been shaped to the outside shape of the hull, that cut would provide a guiding surface that was always perpendicular to the hull's shape, from which one could excavate the remainder of the groove. I spent most of that morning triple-checking the marks I'd drawn against my lofting. Finally, after lunch, with dad standing by ready to unplug the saw if he saw me straying too close to my pencil line, I took a deep breath, and began cutting. Several minutes of intense concentration and steady hands later, I'd done it:

Over the next few weeks, I proceeded to dig out the remaining wood using hand tools, always making sure to leave an extra quarter inch, just to be safe. This excess will only be removed when the planks are actually fitted:

Some of the last remaining chainsaw marks from when I sawed out the keel timber are visible at right, about to get planed off.

Essentially, I was shaping the rabbet as if my planking were only one inch thick instead of 5/4". On the wider sections of the forefoot, I even made small plywood patterns to that effect, just to be sure I got the correct shape.

This portion is near the mast step, and will be subjected to some of the most intense forces while sailing, so a tight seam that fits well against the planking is essential.

At the bow, following Larry's advice in his book on the process, chiseled the rabbet by hand. On the extremely broad face of the stern knee, however, I defined the surface by drilling holes with a 2" diameter carbide Forstner bit and a stop collar set to 1" deep:

In addition to defining the surface, it removed a lot of material, making chiseling easier.

...then chiseled and sanded the surface down until it was smooth and uniform, with just the faintest ghosts of the drill holes remaining:

As with all operations involving the backbone, I then had to flip the entire assembly over, and do it all again. Needless to say, I'm getting kind of tired of flipping the backbone. Thankfully, once I finish shaping the rabbet on the port side, I'll only have to do that one more time: when I lift it vertically to the position where it will stay for the duration of the project. 

Sounds like a good excuse for a party.

A trip to Blue Sky Country

It took eighteen years, but Dad finally let me borrow his truck!

What do you do when you need to buy something, but don't know where to get it? Google it, of course! And so, early this year, despondent over my insufficient quantity of black locust flitches, I took to the interwebs in a desperate attempt to find a very specific -and rare- type of lumber.

But first, a little background:

In order to be suitable for construction, wood can't be fresh cut from a recently felled log. Such lumber, termed "green" in the sawmill lexicon, still contains large amounts of moisture from its time as a living tree. If sawn to shape and used for building in such a state, the wood will warp and contract as it dries, causing untold pain and suffering as measurements that you swore were correct suddenly aren't anymore. In order to solve this problem, the wood must be seasoned until it achieves "equilibrium moisture content", that is, a steady state where the humidity within the wood's fiber structure is roughly the same as the long-term average humidity of the air at the building site. Traditionally, this was accomplished by air-drying the lumber. It was stacked in a shed in such a way that air was allowed to circulate freely among the timbers until they had reached equilibrium and were dimensionally stable. The general rule of thumb is that, done properly, this process requires one year of drying time per inch of your wood's thickness. 

Early in the my search, I got a text from my dad saying that he'd found a few freshly-cut logs of black locust on Craigslist in New Jersey. The problem, of course, was that I needed the wood ready to use *now*, not in 2018, which was the earliest that my two-inch thick frames would be ready to saw out from slabs of such a log. Since the 20th century, the lumber industry has tackled the problem of seasoning with a process called kiln-drying, in which large batches of green wood are wheeled into room-sized kilns and heated until they achieve a given moisture content - a process that takes several days instead of several years. While fine for most applications, however, this is less than ideal for boatbuilding, as (1) such lumber, overwhelmingly destined for making buildings, is sawn to standard, square dimensions before use, eliminating any natural curvature that I could use to my advantage in the boat and (2) unless great care is taken during the process, kiln-drying can remove moisture too rapidly, collapsing the cells that make up the wood and weakening it compared to air-dried stock. Industry often prioritizes speed to such a degree that I just don't trust the stuff.

Such was the problem that faced me as I turned to the search engines. I was looking for lots of large slabs of black locust, air-dried, ideally pieces whose natural curvature hadn't been sawn off by our society's pathological obsession with Euclidean geometry. I was reasonably certain I'd end up compromising on one or both of those qualities, but I figured it was worth a try. At the top of my search results was a website with the remarkably specific name of "A black locust connection", whose web design would not have been at all out of place on a GeoCities page circa 1995. Still, I resolved to poke around a bit. In the "About us" section I learned that "Blue sky" -the name of the business, I supposed, "uses a Wood-Mizer bandsaw mill to create beams, boards and planks of various sizes, depending upon the needs of customers." So far so good, I thought. I clicked about further to see photos of some of their stock. This image appeared, and my heart stopped:

That photo had been taken three years ago. If those slabs were the right thickness, and were still there, then they were exactly what I was looking for. I reached for the phone. 

"Blue Sky," a gravelly New England voice replied on the other end of the line. 

I inquired after the curved slabs. They were still there, I was told, but a boatbuilder in Vermont had also expressed interest. In a panic at this news, I looked at the calendar and asked whether I could stop by the day after tomorrow. In my rush to beat the Vermonter to the prize, I never even asked the owner's name.

Forty eight hours later, after a marathon drive to the hilly woods of northwestern Massachusetts with my dad's borrowed pickup and flatbed trailer, I arrived at "A Black Locust Connection". My anonymous woodsman looked the part, with round spectacles poised over a face sporting a chin-length gray beard. A red lumberjack's shirt completed the ensemble. About the only thing that reminded me of the 21st century about the place was the four wheel drive all-terrain forklift (its rear tires alone went up to my chest) in which he tore about the steep slushy switchbacks of his woodland empire with disconcerting velocity. The cab only held one, so I was invited to come along by clinging to the back of the chassis above the winch spindle. Hypnotized by visions of boat framing, I agreed.

Arriving at his drying stacks, it was immediately clear that the wood available more than justified the white-knuckle ride, and after several trips back and forth to the truck, I was certain that I'd accumulated enough of those beautiful curved flitches to frame Astraea from stem to stern with naturally grown rock-solid ribs:

Before I left for home laden with the spoils of my expedition there was the small matter of the check (writing enormous checks for raw, unfinished wood is something that I've yet to get fully used to), and the embarrassing question of to whom I should make it out. 

"Blue Sky's my name," replied my newest friend, "like I said on the phone."

Oh.

"Yeah, when I started in this business, I realized that when I cut down a tree in the woods, I would make a little patch of blue sky, so you see..."

I saw indeed.