October 1, 2006
Bits and Pieces
By Douglas Bernon
We have a friend, a successful sailboat racer, who admits that in his youth he would try and confound his opponents by any means, fair or foul. When passing another boat or being passed, he would sometimes throw rusty cotter pins or half-sheered bolts up against their main sail, so that when they fell to the deck, either the sudden sound or the later discovery would unnerve his adversaries. I can see why. I hate finding broken bits anywhere. Every morning when Bernadette and I are on passage, I make a full and leisurely tour of our deck, looking up and down, examining this and that and hoping, always, to find potential problems before they surprise us.
I also check the engine every day we’re under way. Granted it’s a cursory look. I don’t study every inch, but I look for wet, salty or oily evidence of something that might be leaking, loose, oozing, or just not right. I listen to the engine. I smell it. I take a basic temperature with my hand. I check the oil and the belts and the level of anti-freeze in the overflow tank. What I don’t always do, though, is reach under the engine into the small bilge and feel for evidence of something having gone haywire and tucked itself into an inconvenient, unpleasant cranny. Or at least I didn’t used to.
In Isla Providencia, after Mr. Bing and I determined the easy-to-mend difficulty with our water pump, I was utterly surprised to discover shreds of black rubber in the bilge under the engine. At first I checked the belts to see if one had thrown off a bit, but the pieces I found were too thick to have come from any of the belts. I checked the hoses; all were intact. Then, as I examined the pieces of shredded rubber collected in my hand, it dawned on me where they had to have originated.
Ithaka has an ingenious engine arrangement. Coming off the front of the engine (the opposite end from the shaft leading to the propeller), there’s another small shaft (sometimes called a power take-off) that extends forward, and ends up being hidden under the settee in the main salon. Belted to this shaft are two devices: the high-output alternator dedicated to our house bank of batteries, and the belts from the refrigeration compressor.
Anyone who has aligned an engine knows that it takes time and patience. After all, one measures not with a yardstick, but with a set of feeler gauges that are merely 1/1,000ths of an inch thick. With this kind of precision, when the faceplates meet, if they’re the tiniest bit out of whack, they may as well be WAY outta whack. Add to this inevitable and minute disparity that there is yet another axel of sorts on the front end, and it’s clear why it’s impossible to perfectly align everything. To compensate, many engines have a flexible coupling between the two plates; this is an incredibly strong, highly forgiving, rubber “doughnut” that, when secured around the two rotating devices, allows them to spin together with a minimum amount of vibration. When I grow up, I aspire to be more like them: tolerant of imperfection.
Turns out, it was our flexible coupling that was the source of the rubber shards at the bottom of Ithaka’s engine pan. Imagine a 6-inch-diameter baby-carriage tire with a three-inch center opening. Now imagine that this tire is slit open so that it can slip over the two turning parts, then be bolted to both parts -- thus absorbing the slight wobbles of the two rotating together. Think radial tire now, laced with embedded fibers, that give it its extraordinary strength.
On Ithaka, this inexpensive coupling is pretty useful, and although we have many thousands of dollars worth of spare parts—injectors, starters, alternators, and watermaker heads—I’d never thought to get us a spare for it. And on Isla Providencia, the only hardware store was fresh out. Without the power-take-off doing its job, it would take us nigh on forever to charge our batteries from the smaller engine-mounted alternator dedicated to the start battery. End of the world? No. Damn inconvenient? With several remote anchorages and an offshore passage to the United States ahead of us? You bet.
Providencia has an internet café that’s open several hours a day. Bernadette spent some time in there Googling “flexible couplings” and were able to locate a company in America who makes our particular kind of coupling, called a Fenaflex. They said they could ship one to our next destination, Guanaja, so we ordered the part and had it shipped to our friends Jack and Elizabeth at Lighthouse.
Between Providencia and Guanaja is a three-day sail. But we also wanted to stop in at the Vivorillos, a remote bank off the coast of Nicaragua. We decided to cobble together our own temporary repair, figuring it wouldn’t make anything worse; that it would work as long as it worked; and that when it stopped working we could high tail it to Guanaja. However, when Bernadette I asked each other how we might best go about effecting this jury rig, nothing leaped to mind – that is until I asked myself what would David on Zia Lucia, or Cade on Sand Dollar, or Frank on Simba do? They’re the most creative fixers I know, and I’ve often thought they could make anything out of chicken wire and bubble gum.
Thinking that very expression opened up the door for me. If those were such fine ingredients for repair work, what were the equivalent goodies I had squireled away on board? The answer seemed to be fiberglass matt, Interlux’s two-part epoxy and 3M’s 5200 spooge. I sliced up thin strips of fiberglass matt, then cut it further and teased it apart so that there were small pieces and individual strands as well. I saturated them thoroughly with the two-part epoxy and painted the mixture into the inside of the tire where light was showing through. I used the same material to cover the holes on the outside as well. By lacing it on both sides of the coupling, I hoped to create a stable web onto which I could lay the 5200, but I didn’t want to use too much matt or epoxy; the goal was to keep things supple. Anything rigid might prove too brittle -- sort of like people.
I cut up more itty-bitty shreds and mixed them directly into a mound of 5200 already squirted out of the tube, figuring that it might give some radial strength. Then, on the outside of the tire where there were major chunks missing that had spun off like a bad retread on the highway, I worked in the mix, and we let it cure for 72 hours before putting it back on the engine and giving it a test ride. A week probably would have been better, but we were growing impatient to move on.
Once everything was reassembled and the doughnut was back in place, we fired up the engine at low RPM to see if the little tire would hold together, and not peal into piecemeal orbit. We increased revs until we were full throttle, and still the little bugger held together. We used it steadily to charge our batteries for the remainder of our time in Providencia as well as in the Vivorillos.
By the time we got to Guanaja, some ten days and twenty-plus hours of motoring after installation, there was still structural integrity. Despite the high torque of the engine, the repaired coupling had not shredded completely, although its demise was clearly foreseeable. I was again picking bits from the bilge. In Guanaja we received the new Fenaflex (and a spare as well). I took off our homegrown version and cinched down its replacement.
Looking back, this was a pretty successful short-term fix, but now I know I would’ve done it differently. Instead of using the two-part epoxy (which really is not made for this application but did its job with gusto) and fiberglass matt, I would’ve cut some strips of dinghy patch and used the two-part rubber glue to fashion the support layers. Then, once I had the holes covered, I’d lay in more layers over that with a good bit of fiberglass matt as well as the glue. I could have achieved, I think, a more durable construction. But the real moral of the story is not about spooge or matt or engines or glue. It’s this: If life is going to work on board a boat, or anywhere else, a flexible coupling is required.