DIY boat owner 2005-#2 www.diy-boat.com 1-888-658-2628 contents 2005-#2 columns 18 18 Core Doctor 7 SCUTTLeBUTT Balsa, plastic foam and plywood cored There’s Truth in Numbers: Every boat decks and hulls can be slowly poisoned sold is assigned a hull identification by the insidious infiltration of minute number that gives the buyer a clue to amounts of water over the years. You the boat’s builder and true age. Here’s how to crack the code. By Patricia can avoid problems by applying proper Kearns techniques to install new hardware and 30 ELECTRIcAL reseal any leaking hardware now. By Batteries and Charging FAQ: John Nick Bailey Payne, DIY’s electrical advisor provides solutions to questions submitted to 42 DIY’s Technical Helpline concerning 26 A Calculated batteries, battery switches and charging Approach To Proper systems. Gear Ratios 33 ELECTRONICS All About Transducers: Here’s what you Many modern diesels available for dis- need to know about the construction, placement powerboats and sailboats selection, installation, routine mainte- are offered with transmission and gear nance and troubleshooting tips of depth, ratio options. Follow these steps to speed, windspeed and wind direction determine the proper engine power rat- transducers. By John Payne ing, transmission gear ratio, propeller 37 SAILBoAt RIGGInG diameter and shaft diameter for your The Shape of Speed: Whether you’re a 51 novice or veteran sailor, you’re sure to boat. By Robert Hess gain some useful information about how to set your sails for various wind condi- tions. By Roger Marshall 42 Boat Owner’s 5 PoWeRBoAt RIGGInG Guide To Used Boats Is There A Sterndrive Repower In Your If you’re going to invest in a boat that Future?: Replacing the engines in an needs renovating, you will recover more older boat may just be the better option of your investment, in both dollars and than purchasing a new boat. This article discusses the costs and steps to pleasure, if the subject boat is a “blue repower with new sterndrives from take chip” issue. This primer will put you out to start up. By Steve Auger 55 on the right course in the selection pro- 55 DIY PRoJECTS cess. By Patrica Kearns Installing a Hot Water System with a Raw-Water Cooled Engine; Ease Up on Your Starter; Sliding Door or Window 64 Finding Volumes Lock; Gentleman (And Ladies) Flush Do you know your boat’s tank capaci- Your Engines; Redesigning Marine Trader Galley ties? Here’s help for our DIY math- challenged readers. These formulas Departments will help you calculate the volume of 2 CURRENTS fuel, waste and water tanks on your Letters, News, Wanted boat. By Roger Marshall 0 TALKBAcK Q&A Questions from DIY Readers PELA 2000 OIL CHANGE VACUUM PUMP WIN 0 DIY TECHnIcAL HeLPLINE – It’s FREE Log onto www.diy-boat.com for: Technical help with your subscription. See •DIY BACK ISSUES insert on page 49 or log onto DIY ONLINE at •1995-2004 www.diy-boat.com EDITORIAL INDEX 7 TECH tIPs •DIY EZINE (Web version) FREE Technical Help with your subscription To subscribe call 1-888-658-BOAT or log onto DIY ONLINE at www.diy-boat.com DIY boat owner 2005-2 (www.diy-boat.com) 1-888-658-2628 It’s good practice to close all water Currents intake seacocks when not in use to Edited by Jan Mundy alleviate the remote possibility of mus- sels making their way into the engine. Caution: Mussels Coming to your Lake Outboard owners should raise the engine above the water intake when We keep our 11-Meter Trojan on 66-mile long Grand Lake in Oklahoma. The pres- not in use. You might have to dive ence of zebra mussels has just been confirmed in the lake. Will the mussels attach underneath the boat to check about to the boats and docks like barnacles? Will they settle in engine exhaust systems twice a year but, other than that, it’s that may run only every few weeks? Should we find a means to close off exhaust not yet a real issue though, with time ports that are immersed? Are they likely to cluster on or in underwater seawater to study the situation, could become a strainers? I assume we have some time before they become a real issue but I would treatable threat. like to be as prepared as possible to protect our floating docks and boats that stay Most states have a Zebra Mussel in the water year around. information line through the State Sea Darrell Gentry, Independence, Kansas Grant organizations. Another good source of mussel info is the U.S. Army Corp of Engineers. Stay Connected at Sea Need better cellular phone reception on your boat? You can boost the phone signal up to 50 miles offshore by con- necting to an external antenna that plugs into your phone. Today’s mobile phones use a 3db- gain antenna. Connecting to an external Nick Bailey 9db-gain antenna gives you the power Highly visible zebra mussels on outdrive and trim tab won’t hinder operation of the boat to reach out farther. This antenna flat- but will make it very inefficient. tens out the RF signal so it resembles Your question prompted us to investi- which simply fits on the engine intake more of a pancake instead of an gate further into mussel affairs. Given cooling line that holds a replaceable omnidirectional concept. Manufacturers the insidious spread of this invasive puck about US$50. A similar device advertise that this advantage, combined species, it’s not surprising that they is the Zebra 2000 (US$100). It turns with an antenna mounted atop the have spread from the Great Lakes to on automatically for five minutes every mast or on an 8' (2.4m) stern-mounted Oklahoma. (Blame trailerable boats, 24 hours to zap the mussels in the pole, will boost reception to the 30 to especially those that are water-bal- cooling line. “You should inspect the 50 nautical-mile range. This range is lasted.) In a few years, depending on water intake and exhaust systems prior an improvement over your VHF radio the speed with which they multiply and to operating the engine if the boat has reception and means you’ll be able to spread, you’ll find mussel colonies on not been run for more than a week keep in touch all the way across any of dock pilings and other objects that are or so,” recommends Bill. Also, fit a the Great Lakes, possibly even during stationary and submerged. In our area, Head-O-Matic Tankette (US$115) on a passage to the Bahamas. For phones the hype in the past 15 years has been the intake line to your head to prevent without an antenna plug-in, you’ll need much stronger than the bite. What it zebra mussels clogging the hose while to purchase a new phone or an ampli- has done is increase the duck popula- the toilet also benefits from the auto- fier repeater, such as Digital Antenna’s tion (food for them), hindered sports matic chemical treatment of the head 3-watt PowerMax (about US$350). fishing (consumed spawning grounds) with every flush. This connects through the airwaves to but, because mussels are bivalves (like According to Nick Bailey, DIY’s a local receiver to boost the power of oysters) they do a great job of filtering maintenance guru, damage to engine your phone. For the ultimate wireless, water and so are also responsible for interiors and the “hidden” threat is exag- use a Bluetooth headset for hands-free the cleanest water we’ve had in a very gerated. “I have yet to see an inboard communicating as you move about the long time. engine have serious mussel issues on boat. Zebra mussels cling to any hard either the water intake or exhaust side,” surface. You can protect marine engine explained Nick. Mussels prefer outdrives EPIRBs For Rent water intakes with products made in or any other external surfaces that have Whether you cruise or race you need Canada, where they have had lots of not been painted with antifouling. “On a to be prepared for the unexpected. experience in the last 15 years with rarely used outdrive without antifouling Next time you head offshore or plan an these wee beasties. Bill Milne of paint, they tend to choke off the water overnighter, if your boat is not equipped Alex Milne & Associates recommends intake slots and cause engine overheat- with an emergency position indicating installing the firm’s Zebrex (US$50), ing,” says Nick. rescue beacon (EPIRB) consider renting DIY boat owner 2005-2 (www.diy-boat.com) 1-888-658-2628 one from BoatU.S. Foundation’s EPIRB of the shaft to lock it in. However, the Currents Rental Program. As a public service, it article on page 18 in DIY 2005-#1 supplies these $900 life-saving devices issue shows an illustration with the half for just US$50 a week.The EPIRB nut at the end of the shaft. Which is to 2% can save you approximately Rental Program is funded by the volun- correct? 8% on the policy premium. If you tary contributions of 590,000 BoatUS. Alan Porter, “Te Tiaroa,” moor your boat in the hazard zone, members. For more information, call Victoria, British Columbia be sure to complete a thorough safety 888-663-7472 or visit www.BoatUS. and storm preparedness plan that com/foundation/epirb. Jan Mundy replies: The illustration on appoints dependable people to care page 18 labeled Figure 1 in DIY 2005- for your boat in your absence.