Snap Extenders for Old Canvas

Sunbrella does not shrink. That is the mantra, and for covers and dodger that are left in place, it seems to be the true. It stretches a little when wet, and so long as it is maintained under tension while it dries, it retains it shape. So says Sunbrella. While this seems true for tensioned cloth (our dodger still fits) and it hardly matters for a sail cover, our real world experience with removable Sunbrella window covers has been different, shrinking as much as 5 percent over a period of years. The problem, no doubt, is that these are worst case scenario, repeatedly removed while still wet with dew and allowed to dry. The end result was that the covers became difficult to install and some of the snaps were being ripped out by the excessive tension.

Design For: Winch Handles

Making spare winch handles is a sim­ple job for a competent metal worker. This I discovered because our Norlin designed Scampi, Windhover, has eight winches, all of which were manufac­tured before the world standardized on the 11/6" winch handle lug size. Since Windhover's 9/16" size handles are difficult to obtain and impossible to find at discount I went to Frank "Red' Grobelch, a superb metal­smith/welder of Waukegan, Illinois with some ideas for making up some spares for me. I'm so pleased with the results that I'd recommend the project to any reader who is a competent metal worker or has a friend who is. Even if you can use and buy standard 11/16" size handles, your mental state when clumsy Uncle Fred drops a han­dle overboard will be far more buoyant if you know you can easily replace the lost handle in your own shop.

Fair Through Hull Fittings: Essential to a Smooth Bottom

In light air, a major portion of the total resistance of a sailboat derives from skin friction. To oversimplify, the smoother the boat's "skin" — the submerged part of the vessel — the less power is required to drive it to a given speed. Put another way, given two boats identical in every way, including sail area, the boat with the smoother bot­tom will be slightly faster than a boat with a rough bottom in light air. Most racing sailors have learned the value of a smooth bottom. Ironically, cruising sailors can benefit at least as much from the creation of a low-resistance bottom as racing sailors, although you rarely see a cruising or daysailing boat with a bottom to match that of a good racing boat.

Testers Check Epoxy Sandability, Adhesion, and More

Testers evaluated sandability, resistance to sag, cure time, and adhesion using sample fiberglass panels with 3-by-3-inch test swatches. The fairing compounds were applied and cured in temperatures ranging from the low 60s to the mid-80s. Each test was repeated three times, and the results were averaged. The shaping test involved closely timed periods of even sanding using a block sander and new sheets of 80-grit sandpaper. Testers observed each materials tendency to clog the sandpaper, and measured the volume of accumulated dust after four minutes of sanding.

Bottom Paint Stripping

Although we’ve tackled our share of varnish with a heat gun and scraper, we’ve never used them to strip bottom paint. The obvious concerns would be marring the gelcoat and the noxious fumes created by heating paint solvents and active ingredients. Our first choice for removing antifouling would be sodablasting (PS, October 2011), but as that’s not an option for you, we’d consider chemical stripping (PS, April 2008 and March 2009), wet-sanding, or vacuum sanding.

Chasing Deck Leaks – Painting Non-Skid Decks

The problem with any type of headliner is that it can disguise the origin of leaks. Water may travel many feet behind the headliner before it finds an exit point. If removing the headliner is impractical, you’ll have to begin your detective work from the outside. Any place the deck is pierced by a mounting bolt, hatch, window, mast opening, electrical outlet, or the like, is a potential source of leaks. Assume that if the deck leaks with the boat at rest, the source of the leak will be uphill from the place water appears on the inside of the boat.

Sewn Splices Two-Year Followup

The true test of marine gear is not whether it works when installed, but rather how it functions after years in the field. To that end, we have left samples of sewing materials and sewn test samples in the sun, wind, rain, and snow for two years, and have also sailed with sewn samples in service on our test boat.

Boat Holding Tank Sensor Long-term Test Update

Last year, Practical Sailor installed and tested seven internally mounted liquid-level monitoring kits, including the sensors and their mated remote display panels, in a polyethylene holding tank; the results were reported in the May 2008 issue. The sensors spent the following nine months marinating in the tank, with the occasional sloshing by a tester, before being re-tested to see how well they continued to perform. The test field comprised float sensors, neumatic sensors, and an ultrasonic sender. Float sensors included Sealand TankWatch1, Dometic DTM4, Groco TLM Series, and Wema SHS-8. Air-pressure-fueled sensors included Fireboy-Xintex PTS and Hart Systems Tank Tender. BEP Marines (Marinco) TSI sender uses ultrasonic pulses to measure liquid levels.

A Stronger Screwhole Repair

The fastest way to attach light hardware to a cored deck is a self-tapping screw. It is also the fastest way to have hardware rip out of the deck and end up with a wet core and delaminated deck. But how to replace screws that have gotten loose or prevent a wet deck in your future? One method is to drill and over-sized hole, remove some core, fill the enlarged hole with epoxy, and then replace them with small through bolts (see Spreading the Load Practical Sailor, August 2016). But what if the backside is inaccessible? Can we create an improved repair by filling and reinstalling a self-tapping fastener, without major surgery? What sealing and filling material is best?

Mailport: June 2010

The June 2010 issue featured letters on subjects such as: spiders, addition of color to handheld electronics, DIY boatyard recommendation and propane fridges.

Caring For Your Marine Diesel Engine

Expecting calms for most of the passage, we set out in a flat calm with 70 gallons of fuel. Six hours later, around mid-day, the engine wailed, screeched, clanged, and died. Hardly a ripple stirred the Gulf of Panama.