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Refitting for Performance, Part III

This article is the third in a series by the author detailing the refit of a 1978 C&C 25. To read the previous article click here: Refitting for Performance—Part II.

Days of tinkering with sail control setups and preparing the hull in the boatyard often make the difference between those in front, and those trying to catch up.
Hanging around boat yards can be an experience. There is camaraderie among people working on their boats. And poking around other people’s projects can be informative too. Take for example Pete Sappett. As we worked on Mark McGivney’s C&C 25, Pete would stop by and check our progress. He would watch us make mistakes on the bottom, until we figured out the best techniques. Then he used this method to work on his bottom. We saved him hours! He would also fill us in on how he was getting his Morgan 32 into shape. From Pete, I learned a great trick for removing an old head. He waited until the coldest week of the winter. When the temperature was well below freezing he went to the boat to remove all the old parts. Why did he choose the coldest time of the year to do this? Simple. By doing it in freezing temperatures, anything left "lingering" in the plumbing would be frozen solid, avoiding a real mess. That’s one for the I-hope-I-never have-to-do-that file.

Meeting people like Pete reminded me that there are many ways to improve a boat and no one correct way to go about it. Our articles chronicling the improvements to Mark’s C&C 25 are not meant to imply that these are the only improvements that can be done or the only correct techniques. But we’ve followed a pretty systematic plan and come up with some fairly satisfying results.

The first problem we encountered was fixing the lack of boat speed, especially downwind. We looked at the boat’s underbody and determined that the chipped paint, dimples, and rough surface were major contributors to this problem. On the advice of Kevin Coughlin at Waterline Systems, we stripped the bottom to gelcoat, applied a barrier coat to minimize water absorption, and then add a few coats of an ablative antifouling paint, Micron CSC, to inhibit growth of slime while the boat was in the water.

In sailing, here's where the rubber meets the road. The author is a proponent of quality time spent wet sanding for as smooth a bottom finish as possible.
For preparation, we opted to forgo sanding (too messy and time-consuming) and instead apply a paint stripper, Interlux Interstripper. We found the best results came when we rolled the Interstripper on, heavily, in sections about four feet by four feet. We let that sit for 20 minutes then, with a stiff plastic scraper, removed the paint in that section. We repeated this technique an average of three times per section, then we used acetone to remove any lingering paint. And finally, we did a quick power sanding to get the stubborn paint off. The end result was astonishing to us. In a span of eight hours we took the entire hull, rudder and keel down to gelcoat and lead. Sanding would have taken three times longer and been a lot messier. (When using Interstripper, make sure you are covered completely and you wear a mask. This stuff is strong. I got some on my hands and broke out in a rash. And when I did not wear a mask I got a severe headache, but when properly covered I was OK.)

Now that the bottom was bare we applied four coats of Barrier coat, rolled on. And when that was dry, three coats of the Micron CSC. The last step in the bottom prep process was to wetsand. I am a huge proponent of this. It smoothes the dimples of paint left by the roller or brush, reducing friction. Mark wasn’t sold on it, but I finally convinced him it was imperative, so he took the bottom down to a 220-grit status. ( I was cruising in the Virgin Islands at the time). The end result was a smooth, fast bottom.

When the breeze pipes up, a backstay allows you to flatten and twist the main and spill excess air.
The next problem we tackled was the overpowering issue. Mark had a lousy traveler system that bound up under load, so he could not depower in a puff, and he had no adjustable backstay, so he could not flatten and twist the main when breeze came on. Phil Garland, of Hall Spars and Rigging, helped us chose an adequate sized Harken High load traveler car with the correct track. And we used the diagrams in the back of the Harken catalog to model a split backstay system that was adjustable. The first step to making these changes was to remove the old track. The old system had an aluminum backing plate that we would be able to reuse. To cut the new traveler to size, we lined up the holes on the new system with the ones on the old, measured and marked the length, then cut the ends off with a hand saw. We filled the original holes with 5200 filler to protect the core from water seeping in. Next, we placed the new bar where the old one had been. The holes lined up perfectly so we were able to sink new bolts in the existing holes and tighten. With the exception of a few scraped knuckles while tightening the bolts down below, we had no troubles. (Though Mark did take the Harken car off the plastic holding mount, letting loose a barrage of ball bearings. Harken traveler cars should not be taken off the holding mounts until you are ready to slide them onto the new traveler bar.)

The backstay was simple. Using the diagram No. 4 in the back of the Harken catalog we placed two wire blocks on the exiting backstay and connected them to each other and a third block using an O ring. A line was dead-ended on the aft port backstay tang, run up through the third block and then secured to a double block that hung down. Another Harken double block with a cam cleat was attached to the starboard Aft backstay tang and a line was dead ended on the becket and run up through the top block, back down and up again then through the cleat. Giving us an 8:1 purchase ratio.

After consulting with the sailmaker for the proper sheeting angle, there was some careful measuring and remeasuring before drilling holes in the deck for the genoa track.
The next issue to work on was pointing. Mark had complained that he could not point with boats of similar size and sail plans. No wonder. He was sheeting an old, blown-out draft-aft Dacron genoa to the toe rail. Not only was the sail shape hurting him but he was giving up sheeting angle by not having a proper genoa track. The sail was the easy part. We ordered a North Sails 150-percent Kevlar Tri Radial Genoa. The sail was built as a racing sail, but Mark intends to use it for most of his sailing. The Kevlar has minimal stretch so the draft should stay locked in place. This will also help Mark with the overpowering issue, as the draft, and the center of effort will not gravitate aft and create excessive weather helm, as the breeze comes on. Mark also purchased a new Dacron mainsail. This was to replace a main that was on the verge of exploding.

The genoa track was the most difficult job to do. We had no old one for reference so we needed to be sure that we put it in the correct spot the first time. If you want to get a good laugh, drill a virgin hole in the deck of a friend’s boat. The look on Mark’s face after we drilled the first hole was one of unsure agony. We knew from our sailmaker that the key sheet lead would be 18 and a half feet aft of where the headstay intersects with the bow and three and a half feet from the centerline of the boat, giving us an 11-degree sheeting angle. We measured back from the bow on each side and marked an arc in pencil. To get the athwartship measurement we measured the stern width and marked it at 50 percent. And we measured the mast butt plate on deck to the rails to ensure that the mast was centered. (Close enough). Using a string we tied to the mast we pulled it taught to our 50 percent stern mark. This gave is a centerline. At each end of the arc we marked three and a half feet from the centerline. This would be our focal point. We then measured three and a half feet from the center to two feet forward of the arc and marked that. Our track would sit straddling the centerline marks, three feet forward of the 18-and-a-half-foot mark, and one foot aft of this spot. This would give us room to use a smaller sail at some point and to drop the lead back in heavy air to depower the genoa.

The final touch. A one-inch oak backing plate provides ample strength for the loads the track will support.
Our backing plate was a piece of one-inch oak. We drilled holes in the oak using the track as a template. Then, after laying the track on our marks, we taped it in place and drilled a fore and aft hole through the deck so we could make sure the backing plate would fit down below. Due to a bulkhead, we were force to cut the backing plate into two pieces and lay it on either side of the bulkhead. Comfortable that our backing plate system would work at that location, we drilled the remaining holes, filled them with 5200 and sunk our bolts through. On the back of the oak backing plate we secured each bolt with a fender washer, one lock washer and a lock nut. The job was easier than we would have assumed. We spent more time questioning ourselves than actually laying the track.

The hard stuff was now done. We ran two new halyards and bent on the new main. So far everything fit like a glove. The project had gone too easy, so I figured that the new genoa would be a problem. Maybe we measured wrong, or the design would be off or, worse, we put the track in the wrong location. I have to admit I was nervous as we pulled it up for the first time. But why worry, the sail fit perfectly. With the lead at the aft mark that our sailmaker had given us, in a light breeze, the sail sheeted right into the spreader tips and just kissed the chain plates.

Our first test will come soon when we race around Prudence Island in Narragansett Bay. Will all the work pay off? Did we solve the performance problems we set out to solve? The answers will have to wait. I had to leave to go to our sailmaker’s batchelor party. Priorities, you know.

Suggested Readings:

Refitting for PerformancePart II by Pete Colby

Refitting for Performance by Pete Colby

Mainsail Controls for Performance by Dan Dickison

Buying Guide: Head Sail Sheet Leads

Pete Colby is offline  
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