Day 10


As threatened, I ran screws through the sheer clamps near the bow and stern to hold them securely together while I pushed and pulled to try this and that to get the hull panels stitched together. I stitched the side panels together at both ends to get the curve started. It’s clear that the side panels are going to have to lean more than a little toward the keel line all along the hull to meet the bottom panels (which, according to the directions, need to be spring clamped together tightly, almost vertically, at their ends to keep from “flattening out”).

I spent the better part of an hour re-measuring scarfs and widths and making damn sure the bottom panels are pointed the same way the side panels are — that’s how far from connecting up everything looked and felt. Eventually, I got the plans out and marked some “stations” on the plywood so as not to get the head-spins every time I need to get oriented. The boat is upside down on the bench; it’s to be rowed “backwards;” and the plan drawings show the bow and stern left to right while the boat sits in the shop “going” right to left. So it’s not surprising that fore and aft can get a bit confusing. I might actually write out some place settings — “Bow!” and “Stern!” — just so I don’t revisit this question every time I look at the inverted hull. I pulled the plans off the wall and laid them atop the project with the plots matching reality. That’s better.

I measured the location of the bulkheads and managed to get them in, briefly. They badly distorted the side panels. Some of that is owing to the reduced number of stitches connecting the side panels to the bottom panels. I tried stitching only every fourth pair of holes in the interests of getting the whole piece attached before going back to do the rest — this strategy may be sub-optimal. It may, in fact, suck. The stitches I did put in place are almost certainly too tight despite my being careful not make them that way. That hasn’t helped.

Loosening several stitches improved the shape greatly, so I think at least and at last that the project is within sight of the range of adjustability. That said, I suspect I am going to have to undo most or all these stitches and start over from one end or the other, skipping no holes, and leaving lots of slack. That’s why extra copper wire and spare drill bits are on the way (they should be here Tuesday, day 12).

Could I not stitch the bulkheads into place against the side panels before wiring the panels together? Their forms would be useful as a template for all the panels. (Yeah, maybe, but don’t. Set them in place from time to time as a reality check, but things will take care of themselves. Then adjust the bulkheads to do what they need to do.)

To keep the side panels tilted in toward the bottom panels to facilitate stitching, I think adhesive tape of some sort could play a useful part (some will arrive Wednesday, day 13). No. See below. If I did this sort of thing often, I would make a tool to assist: picture a string, wire, or cord with a sliding, lockable collar; thread it through two holes, set the collar to compress the chine edges of the side panels and proceed. Think of an industrial version of a camping guy wire with the tensioning button set to “stun.” A few cords like that set in place to pull the side panels together would make mating the side- and bottom-panels less exciting. Just release the buttons and move the cords on down the hull when each segment is done. Tape should serve a similar purpose. The plans don’t mention using any such thing, so it’s likely that in the end, none of this is needed. Just keep the stitches very, very loose, and use the tape when it helps. The plan seems to suggest that just walking around the boat adjusting the tightness of stitches until everything shapes up and all lines are fair will do.

OK, yeah. The tape was an interesting notion, but the trouble turned out to be that the bulkheads were slightly too broad. See Day 13.

Here’s another particularly useful thread from the CLC builders’ forum:

https://www.clcboats.com/forum/clcforum/thread/47177.html

The key bits from this and a couple of others: the instructions don’t mention when to remove the spreader stick. Do that as soon as the bulkheads are in place, however provisionally. They and not the stick will determine the beam; the stick is just one more (complicating) point on what should be a smooth curve. Stitch the panels loosely, then tighten them while watching the boat’s lines; keep the alignment string in place; and give the project a good shake from time to time to release tensions (in the wood, not in you) and to free up bits that are “caught.”

Also a veteran builder on the forum offers this advice against the tyranny of exactitude: “Remember: you’re building a boat, not a Martin guitar.”

That evening,

I wanted to make at least a little unambiguous progress, so I cut out the “inspection ports” (aka “hatches”) in the two bulkheads. CLC routed circular, almost-openings six inches in diameter in the middle of each. It only remained to complete the cut. To complete one opening, I drilled holes with a 3/8-inch bit, each hole just touching the previous one for as much of the circumference as my drill press could reach. It remained to use a chisel to connect the outer perimeters of the drilled holes, and voila, a mess, albeit a perfectly functional one. I cleaned up the edges with a handheld Dremel tool fitted with a spiral bit (which proved exactly as hard to control as I remembered). The chisel, however, cut so well that I decided to use it alone to cut the second inspection port. It’s a 3/4-inch chisel, and I let each bite overlap the previous one a little, so I got maybe 0.65 inches per hammer strike. A circular, 6-inch diameter hole has a circumference of about 19 inches, so this method produced a 30-sided polygon. It’s a pretty good circle! Both openings will be perfect when concealed by the bezel of the hatches that I will set into the bulkheads. (Note to self: need caulking compound, not flat-wound strings.)

I sanded all the edges and both surfaces of each bulkhead and used a foam brush to paint them with epoxy (24g+12g). I hung them up about 8:30 to cure overnight. It’s 60°F in the basement this evening.

None of that is massive progress, but all those things had to be done sooner or later, and now they are.

Tomorrow

I’ll revisit the stitching of the side- and bottom-panels.

Here’s a quick note from tomorrow morning (Day 11), more to come when I get back to stitching: the instructions say to wire the bulkheads loosely in place. I’ve been dry-fitting them now and again, and it is always a struggle. After letting them cure overnight their surfaces are rough and could use more attention. I hammered them into place temporarily and squinted at how they do and don’t fit around the sheer clamps. Then I took CLC’s instructions at their word: “It may be necessary to adjust the shape or position of the bulkheads slightly to get a good fit; it’s better to have a loose fit rather than too tight a fit that distorts the hull panels or causes lumps.” (pg 10 the book of the Oxford Shell). I sanded down some high spots at the top corner of the aft bulkhead, deepened its cutouts, and nudged a couple of angles. The adjustments made the fit “better,” but it’s not perfect, and it is by no means “loose.” The aft bulkhead lies at a flatter angle than I imagined (I’ll remeasure), and the hull has a flatter cross-section in the middle than I expected (thus this hull’s forgiving stability and generous payload, I suppose, and one reason a skeg is essential). The forward bulkhead is not ideal, either, but it is not nearly so challenging as the aft one. I’m still squinting and considering. Mostly I’m thinking I won’t make more changes to the bulkheads until I have everything in hand for another go at stitching, including strapping tape to hold things together while I stitch. I would not be surprised if they end up slightly narrower, with deeper notches for the sheer clamps than they have now. Bingo! See Day 13 for more on that.