Upgrading the C&C 33 Part II

Micron CSC bottom paint again rated 'Fair' in Narragansett Bay.

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Part 2-For hull bottom and topside repair, we love our Porter-Cable random orbit sander and WEST System Microlight Fairing Compound. Micron CSC bottom paint again rated ‘Fair’ in Narragansett Bay.

In the February 1 issue, we described the changes, repairs and upgrades we’ve made to the engine & interior, deck hardware and steering system of our 1975 C&C 33 test boat. This month we’ll tell you what we’ve done to the hull and deck.

The Engine

PS 1, as we sometimes call the boat (mostly for benefit of readers; some- how it lacks any endearing quality), had been regelcoated at some previous time by another owner. When we bought the boat, some of it was chipped and there were the usual scrapes and gouges in the topsides. Clearly, it was time to pretty her up.

This presented the question of whether to spray with gelcoat or a polyurethane paint. On consulting with our yard foreman, we were told that regelcoating entire boats is not recommended because of adhesion problems. In the mold, at the time of construction, fiberglass mat is laid onto wet, uncured gelcoat and so forms a chemical and mechanical bond. Spraying gelcoat onto an already cured gelcoat relies mostly on a mechanical bond for adhesion. Our boat was proof that, over time, separation of the layers may occur.

Painting with a two-part polyurethane was our choice. Some friends reported good initial results with some of the new one-part polyurethanes, such as Interlux Brightside Polyurethane and Pettit Easy-Poxy. But we figured that after toiling with surface preparation for several weeks, we wanted the longest-lasting paint possible, and that’s definitely the two-part formulations. In fact, after one season’s use, those friends using one-part paints expressed disappointment at their abrasion resistance.

Only because our chandlery stocked Interlux products, and we hadn’t yet tried its two-part poly- urethane, we elected to use Interthane. Previously, we’d had good luck with Pettit polyurethanes.

First we had to patch the topsides. Following the advice of the company’s technical bulletins, we began filling scrapes with Interlux 417A and 418B Epoxy Surfacing & Fairing Com- pound ($10.60/pint). This stuff looks like axle grease, and is even harder to mix. It took half an hour to mix the two parts, and even then it wasn’t perfect. Small unmixed balls of it dragged off the putty knife, cutting channels into the patch. Sanding it was okay, but not as easy as the tried and true WEST System Microlight #410 Fairing Com- pound($8.85/4.3 oz.), which we quickly turned to. It’s easy to mix, easy to apply and easy to sand.

And sanding is, of course, the real bugaboo in a topside job. The Porter- Cable 5-inch Random Orbit sander ($129 discount) fared well in our December 1991 evaluation, and we used it exclusively on the hull. Grinders, even with thick foam pads, are difficult to control; half-moons appear all too easily when applying too much pressure or staying in one place too long. Random orbit sanders eliminate most, but not all, dangers.

Purchasing a roll of 125 Carborundum sticky pads (about $25) made economic sense, rather than buying dozens of five-packs. Fiberglass does seem to dull the grit of any paper quickly, and with an entire roll at your disposal, there’s no hesitation to tear one off and put on a new one whenever progress slows. We started with #80 grit and finished with #180. At the time we weren’t sure how much difference there is in sandpaper so we decided to test different brands. The results appear in this issue.

In all, we spent several weeks filling and fairing the topsides. Polyurethane paints are so glossy that any imperfection shows. This prompted us to query International Paint Co. about the use of flattening agents. One professional painter told us he always flattens even topside paint, just a little, because the inevitable scuffmarks don’t show as easily. In the end, the company dissuaded us, saying that high gloss is what the consumer wants. We accepted, resolving to buy terrycloth covers for our fenders and be extra careful when bringing the dinghy alongside.

Two coats of primer and gray Inter- thane paint went on nicely. Two of us worked on dry, calm mornings, be- fore the sun was very high. The primer will cover thin hairline cracks, which is a boon (we recall watching a friend use a Dremel tool to open up scores of cracks on his boat before filling with epoxy putty). This saved a lot of time, and, so far at least, there is no sign of the cracks reappearing.

About two-part polyurethanes: They tend to sag extremely easily; sometimes you can see sags that your fingertips cannot even feel. Ian Palmer of Euro Marine (importers of Antal hardware) suggested stroking vertically instead of horizontally.

It runs counter to habit, but with a fiberglass hull there are no planks or grain to consider. After one person rollered paint on a small area, We used 4-inch foam brushes, stroking only down so that excess paint was pushed onto the masking tape at the boot. This produced a finish superior to our previous efforts stroking horizontally.

Also, no instructions for two-part polyurethanes we have seen, including those for Interthane, adequately advise about the absolute necessity to continually thin the paint. If you wait until the brush drags before adding more thinner, it’s too late. The initial mix is thinned about 20 percent, and every five minutes or so thereafter we added a few capfuls to the tray. Because solvents mostly flash off into the atmosphere, it’s difficult to over- thin the paint. If you study the brush hair or foam serration marks in the paint, and how quickly they flow over, you’ll get some idea of when to add thinner (they should close up quickly). Toss out brushes as soon as they show any sign of loading up; for this reason, foam brushes make a lot more sense as they cost less than $1 each.

Also, no instructions for two-part polyurethanes we have seen, including those for Interthane, adequately advise about the absolute necessity to continually thin the paint. If you wait until the brush drags before adding more thinner, it’s too late. The initial mix is thinned about 20 percent, and every five minutes or so thereafter we added a few capfuls to the tray. Because solvents mostly flash off into the atmosphere, it’s difficult to over- thin the paint. If you study the brush hair or foam serration marks in the paint, and how quickly they flow over, you’ll get some idea of when to add thinner (they should close up quickly). Toss out brushes as soon as they show any sign of loading up; for this reason, foam brushes make a lot more sense as they cost less than $1 each.

The Bottom

Many readers will recall the laborious process we went through to test 22 brands of bottom paint on the C&C (April, 1992). In a nutshell, we sand- blasted the many layers of old paint so that we wouldn’t risk chemical reactions between the new test paints and the old. This was a mistake, as the gelcoat suffered thousands of tiny pock marks. Earlier we’d tired of using paint strippers and sanding, but in hind- sight, it ultimately would have saved time. Again, a good random-orbit sander is a big help.

The pock marks were filled with WEST System fairing compounds (they make several types), and then the entire bottom was coated with clear WEST System epoxy resin. When asked about other brands, such as System Three and Cold Cure, we usually answer that these products work well, too. In fact, we laminated a boom gallows with System Three that has 6) held up beautifully. But only the Gougeon Brothers offer the handy dispenser pumps, and are so readily avail- able in chandleries.

The pock marks were filled with WEST System fairing compounds (they make several types), and then the entire bottom was coated with clear WEST System epoxy resin. When asked about other brands, such as System Three and Cold Cure, we usually answer that these products work well, too. In fact, we laminated a boom gallows with System Three that has 6) held up beautifully. But only the Gougeon Brothers offer the handy dispenser pumps, and are so readily avail- able in chandleries.

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Upgrading the C&C 33 Part II

Darrell Nicholson
Practical Sailor has been independently testing and reporting on sailboats and sailing gear for more than 50 years. Supported entirely by subscribers, Practical Sailor accepts no advertising. Its independent tests are carried out by experienced sailors and marine industry professionals dedicated to providing objective evaluation and reporting about boats, gear, and the skills required to cross oceans. Practical Sailor is edited by Darrell Nicholson, a long-time liveaboard sailor and trans-Pacific cruiser who has been director of Belvoir Media Group's marine division since 2005. He holds a U.S. Coast Guard 100-ton Master license, has logged tens of thousands of miles in three oceans, and has skippered everything from pilot boats to day charter cats. His weekly blog Inside Practical Sailor offers an inside look at current research and gear tests at Practical Sailor, while his award-winning column,"Rhumb Lines," tracks boating trends and reflects upon the sailing life. He sails a Sparkman & Stephens-designed Yankee 30 out of St. Petersburg, Florida. You can reach him by email at practicalsailor@belvoir.com.