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4204 13th Street Court West, Palmetto, Florida 34221 • Ph. 941-729-3370 • FAX 941-729-4955 • 1-800-362-2657 • e-mail sales@marlowmarine.com |
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Bilge Pump-Float switches All boats have at least one bilge pump and many vessels have multiple bilge pumps. These are critical pieces of equipment and this discussion is about the control devices that run them, the float switch. There must be about three dozen types, all claiming to be the best. Inevitably, the float switch will fail before the bilge pump does requiring replacement of the float switch. The next time this is necessary look for the new “MERCURY FREE FLOAT SWITCH” which is now widely available. Industry estimates are that more than thirty thousand mercury switches per year fail, with many dumping their toxic cargo directly into our waters when the pump is activated. Since each holds about ¼ ounce of Mercury, a reduction of 7500 lbs per year would be a meaningful and beneficial goal, easily accomplished. The elimination of Mercury operated bilge pump switches should be done immediately to stop this major contributor of Mercury contamination and poisoning of our marine environment. There is more good news however, in that by eliminating Mercury as the current carrying conduit inside the switch, reliability goes up exponentially. The new switch is tested to over one million cycles without failure. This could be the last time you need to replace a float switch. The next time you visit a marine supply store, why not pick up a handful of the new Mercury free switches for your yacht. The old ones are going to fail anyway; no doubt at an inconvenient time and place so why not put changing them on the maintenance schedule now? When you remove the old ones be sure to put them in a recycle location that handles them. Your town or city hall can advise you where they are located.
What to do when your stainless rusts. The above words are correct folks, “when”, not if your stainless rusts, because it will. Almost all of us are familiar with a common Nickel/Chromium/Iron alloy called Stainless Steel. But a whole lot of us seem to believe that it does not rust and are in shock to find that not only will it rust, it will corrode as well. In the presence of Chloride Salts, Sulfide Gas or Free Chlorine, it will rust and corrode, quickly. It is less than good news that the environment we choose to use it in is loaded with these elements. Swimming pools are obviously loaded with Chlorine and virtually every municipal water supply is injected with copious quantities of Chlorine and other chemicals to reduce the number of parasites in our food and water supply. Back to Stainless and its enemies. Many coastal areas ground water is loaded with salts, as are highways, and so is the element upon which many of us do our boating, salt water. But all is not lost and there are many defenses. Don’t wash stainless with Chlorine in your water. If possible, use a pre-filter to rid the dock supply of as much as possible but in no case add it to your cleaning water, other than for use on tolerant items on board. On the other hand a good quality detergent won’t harm good stainless, assuming you don’t let it dry in place. Wipe the stainless dry with a faux chamois whenever possible, wringing it often to dilute the concentrated Chloride particles it is removing in the water spots. Use a good quality chrome polish. Brasso, a household polish works well too. Each time you polish, you remove ever more of the miniscule particles of unalloyed iron and other trace elements from the surface. These are naturally occurring elements from the manufacturing process that cannot be avoided except in NASA like conditions requiring a baking process to realign the molecular structure of the elements displaced by the welding process. Never clean with chlorinated cleaners and if you can smell or taste a bleach like odor in the dock water, be sure and wipe the surface bone dry before the sun or air does it for you. Never use sandpaper or Scotch Brite like products on mirror polished stainless. Never use Muriatic or Hydrochloric acids. Many miracle cleaners do contain them so read the labels. You can use vinegar if you want to but don’t expect a miracle from it alone on stainless. As great a cleaner as white vinegar is, stainless is a tough opponent. Of course the best thing we can do to combat stainless rust or corrosion is to buy the best and handle it properly. Stainless comes in a large number of alloys and even with the best we must remember the description. “Stainless” ie. Stain Less. They did not name it Stainfree; it’s called “Stainless”. Without a complete dissertation on the various alloys, it could be said that by adding more nickel and chromium to the base iron, we can improve the resistance to corrosion and rusting. An investigation into the various alloys bears out the fact that as those percentages increase, performance is enhanced. But like most tradeoffs, it is not a free ride. Nickel alone will not exhibit the required strength characteristics we seek, and iron will rust at the drop of a hat though very strong. It is simply a matter of the boat builder accepting the increased cost of the proper alloy and the responsibility to process it correctly, as perfectly suited alloys are available. As a practical matter, it could be said that exterior stainless should be of 316 alloy, which is far more corrosion resistant than 302, 304 or 18-8. On all Marlow Explorer Yachts, we go the extra mile and it shows in the most beautiful metalwork in the entire marine industry, often called art. We buy an even higher alloy of raw materials in the 316L category, with the “L” signifying a custom alloy of Low Carbon, which reduces its tendency to corrode or rust. We then test it with a positive identifying chemical that cannot be defeated by chicanery and then process it at the highest levels known in the marine industry. The next time you walk around the deck on a Marlow Explorer, Prowler, Sprite or even our brand new, soon to be unveiled Gypsy, inspect the art that is contained in the metal aboard. It is the envy of the industry, with almost 100 percent designed and fabricated by dedicated men and women allowed the time and materials to do it right. Take reasonable care of it and it will be a source of pride and beauty wherever your compass takes you.
Nuts and Volts: Electricity for beginners.
Electricity is the flow of electrons through a conductor and that flow is called “current”. Voltage is the pressure which causes electrons to flow and it is measured in volts. Current flow is a measure of how many electrons flow along the conductor in a given period and are measured in a term called amps, short for amperes. Resistance is anything that gets in the way of the flow of electrons through the conductor. That resistance is measured in something called Ohms. A perfect resistor is an insulator that allows no current to flow due to the resistance. There are a couple of different types of electricity that are common to our everyday life. One is called AC or “Alternating Current" because it changes its direction of flow very rapidly. The exact speed at which it changes its direction of flow, or polarity is called “X” Hertz. In the United States our AC current changes its direction 60 times each second and is known as “60 Cycle” electricity. Most of the rest of the world uses 50 Hertz and is known as 50 cycle. Many lively arguments have been waged as to which is best. Basically there is a brief moment, sixty of them in US current and fifty of them in European, where the current pauses for an instant at each reversal of direction. If we reduce the hertz to around 25 cycles per second a decent eye can see a light bulb blink on and off twenty five times per second. The other type of current in our daily life is DC and is found everywhere you can imagine. For example starting your car, or operating the lights and thousands of other uses. DC refers to Direct Current and the current only flows one direction. Normally DC current is at a lower voltage compared to AC. To make all this work, a Ground is necessary. Neither will work without it. This ground is usually a connection to the earth, though we sometimes have to chase the path around a little to recognize it. In European vernacular it is called earth and in the US it is called ground. To confuse us a little bit, the ground may not be the ground we are standing on. There are grounds that rely on a wire connecting the system to the water under our boats, which is connected electrically by nature to the soil under the water. Not all grounds are intentional or beneficial. A ground fault for example is what happens if an energized conductor contacts some part of the hull that has a connection to the bonding system on board or another conductor that is grounded. If a crewmember accidentally comes in contact with that conductor, the current can flow through their body to the ground by route of their shoes, hands or other unprotected body part. They are then, in effect the ground and all the current flowing at that time passes through their body. Not good! How good of a conductor the crewmember is determines whether he or she gets to tell a tale at cocktail hour or get grounded permanently, in a grave. The following illustrates that, assuming normal house current of 120 volts ac. One deckhand is cool and dry and has a skin resistance of 100,000 Ohms. The current flow is described thusly. Voltage = 120/100,000 Ohms=.0012 Amperes or 1.2 mill amperes. This current flow would be noticeable, probably a slight tingle or buzz. One deckhand is sweaty and has a skin resistance of 1,000 Ohms. Voltage = 120/1000 Ohms= .12 Amperes or 120 mill amperes. The current flow would stop the heart of all but the most robust and healthy crewmember making them a statistic. There are a lot of considerations when one design a proper electrical system and the overriding rule is that no current must be denied a natural and low resistance path to ground so that no stray currents are present. At Marlow and most quality manufacturers this lesson is never forgotten and every effort is made to build in redundant safety to avoid any opportunity of an accident.
AC/DC Simplified
Electrical energy, as explained by such brilliant men as Franklin, Edison and Ohms, is typically seen in two basic forms. One is DC, or direct current. In direct current, electricity flows in a constant direction. This version of electrical current is seen more typically in a battery powered device, such as a starter for a boat engine, a flashlight, IPod or other more portable application. The other is AC, or alternating current, where the current changes direction at a given speed, described as Hertz, or cycles per second. In the US and most advanced countries, the speed is regulated at 60 cycles per second. Though the English and several other countries claim to be advanced, their AC current is regulated at only 50 cycles per second. 50 cycle electricity has many disadvantages, the chief one being that it does not produce as much power for a given input. For example a 60 cycle 21.5 KW Onan generator regulated at 50 cycles makes only about 17 KW. Certain lights do not perform nearly as well as at higher cycles and a fine set of young eyes can detect the current reversal in such lights as fluorescent fairly often. To make up for this slip up, most countries that use 50 Hertz (cycle) electricity supply about double the voltage to a typical application such as small appliances. When Alternating current (AC) is converted to DC, for example in the battery chargers on board our boats, it gets a tune up and is made to go straight so to speak. DC powered gear is intolerant of all that zig zagging so the rectifier makes it go in one direction only. When we do the opposite, for example using on board batteries (DC) to operate and supply AC current to appliances, the device is called an inverter. In that case, we must take the constant, reliable flow of DC current and make it resemble a drunken sailor on shore leave, zig zagging its way, alternating at a specific rate. An alternator is a device that makes electricity for us from mechanical rotation. This is accomplished by rotating a device called an armature between magnets, usually called “fields”. We can do this to supply DC current to recharge our batteries if we rectify the current or we can leave it alone and it will produce AC current, for example in our on board generators that power air conditioning and other loads that perform best on AC current. A transformer is a device where we can increase or decrease voltage as we require, whether it is AC or DC. Sometimes we get artistic and combine both a transformer and a rectifier in devices like mobile phones, laptop computers, etc. An inverter, such as those routinely seen today can take a DC battery and convert it to AC current, while at the same time increasing its voltage to a usable value, for example 120 or 240 volts, which many on board appliances require. In the case of outputting 120 volts from a 12 volt source, we have multiplied the voltage by a factor of ten, or at 240 volts, a factor of 20. In order to accomplish this black magic, we must also withdraw a similar amount of power from the battery so if we want to us a fair sized appliance, the battery bank must be robust and the batteries capable of delivering large amounts of current quickly. While doing all this business, a certain amount will be lost as heat energy, depending upon how efficient the units are and how quality oriented the boat manufacturer is. Low grade wiring, batteries, appliances, or poor assembly habits can sap a large percentage of the power, sending it into the atmosphere as heat energy. In a proper installation, we can expect that a 16 amp AC appliance load will require no less than about 165-175 amps of current flow from the batteries. Obviously, the battery bank must be robust and properly mated as to internal characteristics. From the above it can be seen that to operate a 16 amp load (that is quite a large load by the way) a D8 battery, which is about as large as is typically seen on boats will be out of juice in about two hours if fully charged to begin with and of proper construction. We must also remember that if we place such loads on a typical automobile type battery, its life will be severely shortened. For a simple formula, it can be stated that any load on a normal battery that is equal to more than about 40 percent of its rated capacity, for more than a few minutes will probably warp the internal plates and shorten its life dramatically. Battery technology is growing leaps and bounds today and we at Marlow Yachts are actively investigating and researching alternatives to find the best answer for tomorrow. Exciting new science is now nearing the marketplace as an energy hungry and ever more environmentally conscious populace enters the arena of commerce.
Tuning your A/C units
Low Cost Chart Plotting
Anchoring Techniques The elements of anchoring include the anchor, rode, method of attaching the rode to the ship, charts, and the depth of the water. Charts are the most important element for good anchoring. They display the location of potential dangers, and the effects of weather and tide in the anchorage. The depth of the water should be determined at high tide for calculating scope, which is the ratio of length of rode to the depth measured from the highest point (usually the anchor roller or bow chock) to the seabed. On the Marlow Explorer, the anchor roller is 10 feet above the water line and adds to the depth of the water. The Rode is rope, chain, or a combination thereof used to connect the anchor to the vessel. SCOPE HOLDING POWER 10: 1 100% 7: 1 91% 6: 1 85% 5: 1 77% 4: 1 67% 3: 1 53% 2: 1 35% Remember that if you are using a chain rode the holding power is much greater; therefore for normal weather and current conditions, a scope of 5:1 is acceptable. When using a chain rode it is recommended that you employ the use of a nylon bridal to reduce strain on the cleats and anchor windlass. While trying to select an anchorage there are four questions for you to answer. Is the anchorage protected? Does the seabed provide good holding ground? What are the depth, tidal range and current in the anchorage? Is there sufficient room? Basic anchoring consists of determining the location, dropping the anchor, laying out the scope, setting the hook and assessing where the vessel ends up. When you have selected where you are going to anchor, idle forward into the wind and/or current to your selected drop anchor position. As you start to lower your anchor have the vessel ghosting aft downwind and/or current while the anchor and rode are paying out. Remember to lay out the rode on the bottom, do not drop the anchor and rode in a pile. When you have reached the selected scope of the rode set the anchor with a slight backing of the yacht. As the anchor digs in and resists the backward force, set the anchor with a small amount of reverse thrust to achieve a thorough set. With the anchor set in your selected location, check to make sure that the boat is not dragging the anchor. Look around to see that your vessel will not be in the channel, that all surrounding anchored boat s will not swing into you, and that you will not swing into other boats. To make sure your boat is not dragging anchor, line up two objects on land and after 30 minutes check the alignment.
Leaving your Boat
for Awhile? Try this…. Tips for Teak
Decks….. Adjusting drip less shaft seals A lot of the yachts
we are selling and servicing are being fitted out with the new drip less shaft
seals. Considering the number of them showing up in yachts we thought it was
time to discuss them again and the care of them with a bit more detail. On Deck:
Think Zincs Before you read on, think about the last time you checked your zincs. Was it more than eight or ten months ago? Did you check them all? Many boaters are not clear about why zincs are needed or how they work. Usually when a boat is hauled for general maintenance the yard will ask to replace your zincs. We recommend replacing zincs whenever your boat is hauled because by that time, they are usually used up, and no longer giving good protection. A zinc should be replaced when it has sacrificed about 50% of its original mass. Webster defines zinc as a bluish-white metallic element, usually formed in combination with other metals, often used as a protective coating for iron. The purpose of the zinc anode is to save a vessel’s more precious metal parts that come in contact with salt water. This means we would sacrifice the less expensive metal in order to protect other metals like bronze and inferior stainless that is more likely to corrode in a hostile environment like salt water. To understand the action taking place under your boat in the water, we know that more precious metals are considered electrically positive, “cheaper” metals are electrically negative, and electrons flow from negative to positive. Under your boat electrons are flowing from the zinc into the bronze and into the salt-water electrolyte. Because zinc is more negative than bronze, it gives up its charges first. This depletes or erodes the zinc and allows the bronze to remain intact. Without this sacrifice, the bronze would lose its negative electrons and over time weaken until that forgotten through-hull eroded away. To make matters worse, moving a boat from cold waters to warmer waters can increase the rate of erosion, making it necessary to add more zincs or to replace them more often. The higher salinity of the Caribbean waters can also hasten the erosion process. To ensure effective protection, all the metal through-hulls should be connected together with a bonding wire or strip that leads to a common spot such as the engine, assuming the boat’s engine has a metal-to-metal connection to the prop shaft. In most cases the best choice to mount a zinc is the prop shaft. Further, any underwater metal parts such as rudders, trim tabs or bow or stern thrusters that can’t be connected to the bonding wire should also be protected by a zinc on each assembly. To be fully effective, all paint and corrosion must be removed between the metal to be protected and the bonding wire. Where the zincs are attached to the shaft and rudders, the metal should be clean and shiny, with no residual paint hindering the contact. Needless to say, zincs should never be painted. This will only make the zinc ineffective, which would force the negative charges to find another place to leave and cause loss of material at that spot. So what can you do? Zincs are like a part of their own little electrical system inside your vessel and are subject to all the rules of electrical wiring, including insulation and “short” protection, and they too need frequent inspection. ¨ Make sure all the bonding connections inside the hull are secure and free of corrosion. ¨ Check that the bonding wire is not in contact with bilge water. ¨ Make sure the contact point where the zinc is installed on an underwater assembly is clean and bright, and not insulated by bottom paint. ¨ If your engine is raw-water cooled, check for a separate zinc anode(s) installed in the block. ¨ There is also a zinc or two on your generator. Check for corrosion and replace if needed. If you can’t locate a zinc on your generator, the zinc has probably eroded away and you should refer to your owner’s manual for the correct placement. ¨ If you have a bow or stern thruster, they also have zincs that need to be checked and replaced as needed. Remember that any stray DC current inside your boat can and will accelerate the loss of zinc into the salt water. Also, as a zinc anode wears away, its surface becomes smaller, which accelerates the loss of material required to maintain the same level of protection. If your vessel lives year round in the warm Florida waters, rule of thumb would be to check all the zincs every twelve to fourteen months. If you’re finding replacement is needed more often, you may want to add zincs for longer life.
1. Lubricate canvas zippers with a wax candle. It makes them slide nicely and will not attract dirt and stain like ordinary lubricants will. 2. For those zippers that won’t stay closed, spray them with a lacquer based hair spray. Let them dry and they will work like new. 3. Spray a small mist of vegetable type kitchen oil on snaps. They will snap, unsnap with ease. If you use a q-tip, Vaseline works well as a lubricant and corrosion proofing though it tends to attract dirt. 4. If you have a nick appear in a windshield or window, (boat or cars) apply a small drop of clear nail polish as soon as you see it. It will fill the nick and stop further cracking. Truly miraculous! 5. To clean your windows inexpensively but so they sparkle, use windshield washer fluid and old newspapers. It really polishes them. If you want them to stay really clean and repel dirt-water, use Rain-X. This stuff really works. Ask Andy Rooney. He caught all kinds of flack from legions of customers for denigrating it on 60 minutes. After trying it he became a soldier for them. 6. Store deck cushions standing on edge, zipper down. This will allow them to dry. When you order your new Marlow Explorer from us we will install Nimbus closed cell foam as standard. It does not absorb water. 7. To remove a light layer of hull oxidation without removing good gel coat, put 5 tablespoons of vinegar in a gallon of water. Sponge it down and rinse well before it dries. If you don’t have white vinegar on board, shame on you. You are probably hooked on Miracle cures (sold on late night TV) that don’t work, wreck other things they touch, and burn your eyes, hands, ears and noses. White vinegar is a great cleaner, deodorizer. 8. When you clean the refrigerator, the final wipe should be done with white vinegar. Don’t wipe it off though. Leave it on and it will do a great job of deodorizing. 9. To remove creosote, tar, oil, etc. from your boat, spray a little oven cleaner on the spot. Let it sit for 5-20 minutes depending upon the thickness of the mung on your boat. Rinse off and repeat as required. 10. Get yourself a fake chamois. Buy the one that comes packed in a plastic cylinder. Don’t lose the cylinder and always store it damp with the cap on. I have one over 20 years old that although a bit worn, works great. These manmade products will outlast and vastly outperform any natural chamois ever sold. Each time you dry the boat, it is like polishing it with the finest grit you could imagine. Over the years it will literally polish paint, gelcoat to a smooth finish. Buy the thickest one you can find in your favorite marine store. Save the Chamois! 11. If your engines are using a bit more oil than they used to, consider the new Synthetics such as Mobil One. I have switched all my collection of autos and trucks over to this product and it is remarkable to me. Engines that used a quart of oil at 12-1500 miles now go twice that before a quart is gone. Cold starting is quieter and it stays cleaner looking longer. Though it is more expensive the extended oil change intervals it affords reduces the cost to tolerable. Fuel Tank Maintenance For the GB, Eastbay and OA owners we want to remind you to inspect and clean the tops of the fuel tanks on board your yacht before another hot summer contributes its corrosive effect to the metal. If the tanks are alloy (aluminum) take no pleasure, assume no immunity from the ravages of salt water, especially hot salt water, as we know it here in the South. We have replaced the alloy tanks in an East Bay in less than three years after delivery due to salt water lying on the top and sloshing on the bottom in the bilge area. First, go and buy a product called Ospho if available in your area. Most paint supply stores, Lowes or Home Depot carry it. If you can’t find it, go to a good marine hardware store and purchase a quart of Star Brite rust killer. It usually comes in a spray bottle, which will make the upcoming job much easier, especially when you adjust the nozzle to make a combination of mist and stream. If you find Ospho, buy a one quart spray bottle to dispense it. Buy either three aerosol cans of Corrosion Block in the 16 oz size or a product called Corrosion X in similar size. If you can buy either in pure liquid form, do it and buy another empty spray bottle to dispense it. If the latter, you will get a lot more bangs for the buck compared to the aerosol, as much of the aerosol can is propellant. Unplug the yacht from the shore power and/or shut down the generator just in case some clown has left an exposed AC terminal or wire end loose in the bilge. Take a hose into the bilge with you and use a nozzle that allows a mixture of fine spray and high pressure, as adjusted. For a normal GB of any style, place the nozzle on the top of the tanks and blast away. If you have not done this before be prepared for a deluge of building debris that will wash off the tank tops. This step is really important because even if the tanks show no salt water lying on them, there will be dust that will absorb and negate the effectiveness of a product we will use later. It’s a really good time to spruce up the cleanliness of your pride and joy so rinse every nook and cranny. If you are feeling heroic, use soap and water. Dawn or Joy work great.
When you have gotten the areas well rinsed, take a plastic bag and gather all the debris that will have worked its way down. You will probably find an old set of pliers, a screwdriver, an assortment of screws, wire ends and maybe even a long lost love letter. One 42 wood GB yielded a quart of Makers Mark whiskey to me, probably squirreled away for a lay day due to foul weather from the Sky Boss or Wife Boss. Make sure the areas around the bilge pumps are completely free of trash or Murphy will pay you a visit. Start the main engines and let the heat from them thoroughly dry the engine room and bilges. When all is dry put on an old long sleeved shirt and pants, with shoes and socks. Get a pair of rubber gloves and a painter’s mask. Don’t use a paper throwaway, unless specified for painting, as they do not offer enough protection. Wear a painter’s hat or a baseball cap and glasses in case you are a klutz. Turn on the engine room blowers for ventilation. Start at the outboard sides of the fuel tanks and spray the rear and tops with a heavy coating of the chosen product. Once again, don’t be bashful! Coat it fully, as this product is going to stop Mr. Rust dead in his tracks. Let the chosen product sit overnight and repeat the rinse cycle described above exactly. When the engine room is nice and dry, turn on the blowers and go below once again. Start outboard near the hull side, as close to the tanks as you can manage. Spray the bejesus (old Southern saying meaning "do it to it with gusto") on the back sides, top and fronts of the tanks. Fog the heck out of the tops so a good coating is on every square inch. While you are out there, spray the steering wires and sheaves of the steering system, wiping them with a heavy hand wash cloth or similar to coat them thoroughly. Your steering system and autopilot will thank you silently with improved performance and longevity. Pay special attention to the areas where the tank rests against any support or obstruction, as this is a place for chafe and is probably laden with salt crystals. Now go back upstairs and take the boat for a spin of an hour or so to allow engine room heat to reduce viscosity and spread the anti corrosive mix. If done as directed the life of the tanks (assuming you have not descended below critical mass thickness) will be greatly enhanced. For the alloy water tanks in the lazarette, or for any alloy fuel tanks that may have found their way aboard, do not use Ospho or Starbrite to remove corrosion. Rinse the bejesus (that word again) out of them, allow to dry and coat them as described. On the subject of tanks, we are developing a mold so that we can replace those metal tanks with Vinylester resin frp tanks in lieu of welded steel or (Yuk) alloy. We think that by utilizing our Marlow Explorers as mini freighters and investing in a set of molds we can reduce the cost to near that of steel or alloy. At the same time we can increase the usable fuel supply by roughly 10% by molding to the shape of the hull rather than a square box. This will also provide a sump to collect all the debris that finds its way into the tanks. Our service yard is always jammed with work but we will find a way to replace them if you prefer that we do the work. We can do it better than anyone because we have done more of them than anyone and we care about our work product. We would not sell our frp tanks to another yard for installation for any number of reasons related to quality of install and ability.
Most yacht manufacturers select stainless steel for applications where there may be an opportunity for excessive corrosion on fittings and fasteners on board. It is in the selection of these fasteners that choices are made as to the alloy that will directly affect the longevity of the part selected. The wrong choice can cause a domino affect if a crucial fastener or part fails, causing damage far beyond the part itself. To shed a bit of light on the subject, let’s dig into it a bit. "18-3-300" has been considered the norm for most marine applications. In recent years a more corrosion resistant variant has become more popular though its cost prevents some from using it. This newer alloy is called 316 and it is considered to be top of the line for exterior exposed applications. Wherever high exposure to elements that cause corrosion is expected, premium manufacturers select 316. In our own Marlow Explorer Yachts we use 316L, which is considered the best one can buy. The "L" stands for Low Carbon. In selecting stainless fasteners and hardware, price is a consideration. Speaking broadly, 18-8 type fasteners are readily available and considerably less expensive than 316 alloys. Though 316 and especially 316L are much more expensive today than the 18-8 family, as the market increases for these fasteners the price should come down a bit. There is a good bit of wrong information regarding stainless steel circulating around the marketplace. One common misconception is that all stainless steel is non magnetic. This is not factual, as a very sensitive magnet will often show a slight attraction for many stainless steel alloys, with the lower grades being more magnetic normally. A washer for example of 304 will often show an attraction for a magnet and a 302 allow will nearly always have an attraction. Often times the two alloys are mixed in the cold working process and a bit of 302 is mixed with the 304. When this happens it will attract a magnet and will not be as corrosion resistant. When we purchase a stainless steel part many boaters expect it to be completely free of rust or corrosion. It is not. Even the very best alloys will show rust or corrosion in the right conditions. Think about the word "Stainless". It means stains less than other metals like iron. It does not mean stain proof. There are two conditions often confused regarding stainless. One is rust and the other is bleeding. They are very different. Rusting is the actual breakdown of the metal part due to a prolonged or intense exposure to a corrosive atmosphere. Where actual rust appears we are seeing the physical deterioration of the metal. Bleeding on the other hand occurs when a fastener is dirty or has other corrosive materials on its exterior. Yes, dirt is a corrosive influence on stainless steel. The dirt reacts to the corrosive atmosphere and breaks down, with the result being discoloration of the fastener and surrounding area. This appears similar to rusting since the color of rusting and bleeding are the same. The difference is that the metal is not corroding slowly away when bleeding occurs. To combat bleeding, stainless must be kept clean, due to the fact that stainless requires oxygen to produce and maintain the protective coating of chromium oxide, which stainless produces in an oxygen rich environment. Many times we see bleeding coming from under a fastener that is perfectly bedded. This oxygen free environment is ripe for bleeding, as the stainless cannot produce the Chromium oxide that protects it in an oxygen free environment. This problem can be helped by "passivation" of the part. This is often done by electro polishing the parts by dipping them in an electrically charged liquid that cleans the surface impurities from the part. If followed by hand buffing the part will produce a lustrous surface, which will resist rust and bleeding very well. Although there are many choices available in stainless parts, you really want alloys in the 300 family. Many people refer to these as the 18-8 family, which just refers to the basic configuration of the formula being 18% chromium and 8% nickel. The most common classifications for the 300 series are: 302, which is commonly used in the cold heading of screws 303, which has a much higher percentage of sulphur. This type is particularly well suited for machining. When a bolt is produced in stainless, it is often times machined from 303 alloy, whereas most screws heads are made by cold forming them and 302 is often used. 304, which is typically used in the manufacture of high quality machine screws, bolts, etc. 305, which is often used for deck fasteners, for example under the teak plugs. 316, which has Molybdenum added and provides a much greater resistance to corrosion. 316L, which is a more highly refined stainless showing less carbon steel. It is very corrosion resistant. When the duty for stainless goes beyond the normal ability of these alloys to perform reliably, some manufacturer "hot chrome" plate the stainless for additional corrosion resistance. It has not been conclusively proven that this plating does much for the stainless except make it shinier. It is our opinion that if even higher performance is required there are other alloys that increase the nickel content and improve corrosion resistance, albeit at high cost. Some examples of this are Alloy 20, 630, Hastelloy and an old, expensive favorite, Monel. Specific alloys will produce specific results that can be tailored for the job at hand. Aquamet 22 for example is a wonderful, though very expensive shafting material. Highly corrosion resistant yet incredibly strong, it is ideal for today’s high torque engines turning large propellers. There are many factors in selecting the alloy we require for a specific job. Generally speaking, as the corrosion resistance increases, ultimate strength decreases. Manufacturers have learned many tricks of the trade to overcome this to some extent by alloying certain materials, which produces an even stronger product by the inclusion of various trace metals. The best tip we can give for keeping stainless steel looking good is to keep it spotlessly clean with a good paste protectant to help seal out the pollution, acid, etc. which rain from our skies. In areas near the exhaust system for diesel powered boats we will have to be especially diligent, as the burning of diesel with sulphur produces a form of sulphuric acid when combined with salt air. All fuel contains sulphur and the combination is vexing to the skipper who likes nice and clean metal. Once again, keeping it cleaned and a couple of coats of a protectant sealer will go a long way to reducing your cleanup and maintenance. Just keep in mind that they mean "Stain Less" not stain free.
This article brings a small tip that can save literally tons of pollutants from entering the waterways of the USA. We note that most yachts these days are being painted with an ablative or comparatively soft bottom paint that rubs off or wears away, theoretically exposing fresh biocide to the hungry critters looking to attach to MOMS MINK. In theory this works quite well but in practice not nearly as well as the laboratory. In theory the water rushing alongside and under the yacht will wash the bottom of the yacht at all times, therefore wearing away (ablating) the paint and exposing the fresh poison. But hydrodynamic law gets involved and the laboratory theory proves to be hit and miss. Simply explained, every body moving through a fluid (air, water, oil or any other fluid has what is described as a boundary layer. Depending upon the shape of the object, this boundary layer may be paper thin or as much as ½" thick. This layer’s thickness will vary with speed. Within this boundary layer, virtually no flow is established other than erratic or incidental flow. It is in fact a dead zone, where the fluid surrounding the object (your boat hull) is carried along with the yacht for the most part. This hitchhiker actually adds to the load on your engines to carry it, since it has mass and therefore weight. The reason that in some areas the ablative action seems to work so well is simply turbulent water generated by protrusions or changes of shape in the yacht’s hull. In other areas, no scrubbing or ablative effect is seen. That is why ordinary, easily removed scum can adhere to the bottom after a 1000 mile voyage, except in the areas where turbulence washes it free. Factually, except on extremely fair surfaces, very little ablative action takes place except where turbulence is generated. Since many of our customers and friends seem to employ divers to come to the yacht and occasionally scrub the bottom with brushes or a towel, why use ablative paint at all? The answer is marketing driven primarily. A good story has been generated about what could but does not occur to any great degree and most boat owners seem to employ an occasional diver, why not switch to a non ablative paint and stop scrubbing off layers and layers of paint. After all, the objective is to remove the scum that allows the barnacles to attach and become immune to the poison underneath. By the time they spread their glue on the poison, it has provided them with a fine insulator and they are home free, ready for a ride. A non ablative paint may be substituted with a greater concentration of biocide and with routine washing using a soft brush or towel; a clean biocide is exposed without leaching the thousands of tons of pollutants into the oceans. Give it a try the next time MOMS is due for a bottom job. The colors can be brighter, the paint harder and smoother and the oceans a little bit cleaner. What a great thought.
This article is an update of one done about five years ago regarding anchors, chain and anchoring out. In reviewing it, the details seemed as germane now as then so with a bit of revisions and updating we present it in the hope that you will take the advice in the last paragraph and spend a few nights on the hook. If you find a special place, please share it with us so our other members may enjoy it as well. There are a lot of chains available but most of us need only to concern ourselves with just three. High Test, Proof Coil and BBB. Each of these chains has a specific characteristic that differs from the others. Proof Coil has the longest link, with High Test in the middle and BBB the shortest. Chain is given a size based on the nominal diameter of the link that makes up the chain. We usually use chains sized from ¼" to 5/8" though we occasionally see larger. The most popular sizes are 3/8-1/2". Chain measurements are important when considering the whole package. Not only must the chain be of sufficient strength, it must also fit the wildcat on the windlass it will be used on. The length of the chain link refers to the distance between the extreme ends of each link and the pitch refers to the distance between the end of one link to the end of the next link in the chain. In other words a pair of links. For short link chains of the type we have mentioned above, the length is roughly five times the materials diameter and the pitch is roughly six times the material diameter. The word "roughly" is accurate because the small differences in pitch between the various sizes will insure that a BBB chain will not work properly on a 3/8" proof coil gypsy or vice versa. The matching of the chain and the gypsy are obviously very important. Tolerances adhered to by the chain manufacturers must also be considered since not all companies have close tolerances. Fortunately most European and US chain companies do. The chain is made by the manufacturer by cutting off successive lengths and the bending and passing the wire through the preceding link to form the chain. Normally automatic welding machines fuse the ends to create a strong and smooth link. In many chain companies this process is not automated and a given chain will have many variations in it’s links. This will cause you windlass trouble in retrieving or paying out chain. In some cases the tolerances are outside the normal range and the manufacturer will actually stretch short lengths of chain in an attempt to get it to conform to a standard size. The success of this is hit and miss. In commercial applications many insurance companies will require a certificate of test from the chain supplier before they will allow its use on an insured vessel. Reputable chain manufacturers will supply this test data. Since most chain is steel, it will need protection from the elements, particularly salt water and acidic mud. Cleaning it and then running it through a container of molten zinc should galvanize Chain for marine use. This will produce a given thickness of coating on the exterior for protection. Once again, most US and European chain manufacturers do a top quality job in this process. If any step is overlooked the chain will soon rust and stain your decks while losing its initial strength through erosion of size. In our ground tackle specifications we must select it for three reasons. Strength, weight and its resistance to abrasion. The importance of the strength does not need a lot of discussion. We don’t want it to break but we must determine what strength is needed for a given vessel size. Working load limit is the maximum amount of load the chain can be expected to endure. Proof Test is the term used to describe the tensile strength test done by the manufacturer for the purpose of finding defects in the chain. It is the maximum load the chain has been tested to. Various chain sizes are subjected to various loads to determine their suitability and quality. Minimum breaking strength is the minimum load, which the chain was subjected to before it broke in testing. Be aware that these tests are carried out with the chain in a straight pull with a steady rate of retrieval. There are chain testing machines manufactured specifically for this purpose. The only strength description that the purchaser should be concerned with is the working load limit. The other tests are important for other reasons but the working load limit is where you should size your chain. Under no circumstances do you want to get near the breaking point of chain. Choose it with that in mind. Though there are no absolute guides to chain sizes required, ABYC (American Boat and Yacht Council) publishes a manual called "Safety Standards for Small Craft". In this manual ABYC recommends that the working load of new chain be no more than 20 % of its breaking strength. This manual goes on to describe a variety of information related to anchors whether they are used for working anchors, storm anchors or moorings. They break down the various categories of boats such as sail and power for more precise information. Please remember that these recommendations are formulated with the assumption that the craft is anchored in a location to allow freedom to swing and that it is reasonably protected from strong wave action, which causes shock loading on the ground tackle. If you read carefully you can find the right combination to serve your purpose. When you make the trip to the ships chandlery, resist the urge to buy el cheapo chain. You can bet it will not fit as well as the larger manufacturers products and you will find a wide variance in actual strength. You must remember that the anchor is your last, best hope against disaster when everything has gone to the devil in a hand basket. A yacht pinned to a lee shore in a blow with dubious ground tackle is not a pretty thought. For purposes of discussion here and considering that the majority of our reader’s yachts fall into a fairly standard pattern of wind resistance and weight the following guidelines are useful. Proof coil should be avoided due to its long link characteristics which tend to jam in the chain locker and in the hawse opening. It is cheaper than BBB or High Test but in my view not a bargain. Chain smaller than 3/8" is ineffective at times due to its lighter weight, which allows the boat to "pick it up" as it yaws around and this will apply the load directly to the anchor. If the chain does not have sufficient weight to allow substantial catenary sag the yacht will yaw back and forth and will come tight on the chain with considerable force and noise. At times it will sound like the "eyes" of the yacht (the stem) are being pulled out as it comes tight with a crashing noise. Since the chain has no give, this hard jerking will be more likely to pull the anchor from the sea bottom and you will be adrift. Always use a stretchy piece of nylon as a snubber instead of allowing the chain to transfer the load to the windlass directly. This snubber can be bought ready made with a cats paw spliced on it, which will fit the chain. When anchoring let out the appropriate amount of chain and then attach the cats paw to a chain link forward of the wildcat. Let out about 15-20’ more of chain and of course the rope snubber. Fasten the bitter end of the nylon snubber to a cleat, with an extra hitch for safety. Let out the chain until it sags and the nylon takes the load. This will allow the chain to have a shock absorber and the anchor will stay put better. You will sleep a lot better not listening to the chain gyrations in the windlass and rollers. 5/8" nylon will work well on yachts up to about 55’ and then ¾ should be used. To be perfectly clear, never, never allow the wildcat on the windlass to absorb the load directly. It will fail at a most inopportune moment, probably leaving you with 150 feet or more of chain out and a tough job to get it back in the anchor locker. Consider the use of a backup nylon anchor line rather than all chain. For those of you with GBs, your yacht has a very fine (extremely deep angle) entry, which does not like weight in the bow. More than about 150’ of chain has a noticeably detrimental effect on handling and boat trim. If you load up the pulpit with heavy anchors and chain your boat will look like a snow plow, be miserable to control in a following sea and will exhibit the worst look possible in a yacht, "Down by the Head". A stainless steel screw shackle from Wichard will allow you to clip on an extra 150’ of line to your chain if you need it and the weight will be considerably less. If you absolutely require a lot of chain consider having the chain led aft, away from the ends of the yacht to lessen the moment of inertia it produces, similar to how the Marlow Explorer is built. This method of chain storage greatly reduces weight in the ends of the boat and the chain becomes ballast, nestled deep in the bilge instead of a big lever at the ends of the boat detracting from stability and aggravating trim. Don’t let the hippie in the van do this work unless you are absolutely confident he knows a lot about a lot of things as the geometry is fairly complicated and the penalty is a royal pain when the chain jams down below. It is not liquid fueled rocket science, but it does require careful planning and execution. This can be accomplished by an experienced yard using FRP or PVC tubing, properly installed to lead the chain down through the yacht under the berth and into a chain locker area aft of the vee berths in the bilge. Now that you have worked your way through this article, go and inspect your ground tackle. Look at every component. Make sure it is up to the task that may be demanded of it. Make sure the shackles have safety wire on them to prevent the pin from coming loose. Yes, it will if you don’t. Make sure the anchor is held in place by a secure secondary system beyond the windlass wildcat. If the solenoids fail on the windlass motor it may release the chain, allowing it to fall into the path of the propellers. You don’t really want to think about that level of mayhem. Last, use the anchor. Spend some nights on the hook. The night sky is magnificent if you get away from the lights and a quiet anchorage at daybreak is one of the Sky Boss’ great creations.
What’s happening when you lift your dinghy and you hear a couple of pops, a bang and a loud squeal? Is it normal or is something getting ready to let go? Our masts serve two real purposes and a lot of auxiliary purposes. The two real ones are; a. to hold up the anchor light and b. to make your boat look like a trawler. The auxiliary purposes include holding up the antennae and radar, supporting the bimini top and dinghy lifts and carrying the steadying sail. These last two uses cause the biggest loads on the rigging and spars and are the ones we need to keep in mind when inspecting and maintaining our spars. The job can be separated in to four parts; spars, electrical and electronic wiring, standing (fixed) rigging, and running rigging. Your first job should be an inspection from the deck. Make sure lights light, radar antennae go round and round, and radios transmit and receive. Check the operation of winches and running gear. Don’t trust your memory on the rigging, instead take a digital picture or two of each end of the standing rigging and some pictures of the other fittings on the mast and boom. If for some reason your rig is down for a week or two, you may find that your intimate memory has been replaced by some less useful information. Get familiar with the shackles, turnbuckles, tangs, blocks and snaps, so you will know their purpose when you raise the mast. Are the spars straight and spreaders set properly? (Look up the bolt rope slot to determine straightness. Note the quality of paint and adhesion. Are there chafe points that need protection? Does the running rigging lead properly without crossovers? Are there any strange noises or motions as the various operations are undertaken or while lying in bed at night? Identify the problems while you can so you can fix them while you have access. Your mast and boom are made of aluminum or wood. Lower the rig and look for surface anomalies (blisters, bubbles, rot, dings or dents). Blisters and bubbles in paint often cover weaknesses in the underlying materials. Sand them off and see what is revealed. The solidity of the underlying material will lead you to the proper repair. Damage at the ends can be cut off. Damage in the middle leads to wood or metal repair or in unusual cases, spar replacement. Look over all the small parts on the standing rigging and replace any that are worn or corroded. If pop rivets or screws are missing, replace them. Check each shroud by running a cloth over the wire. If you get a snag from a broken wire, replace it. Clean end fittings well with metal polish and then look closely at them. Most are swaged and it will be hard to tell if they are about to fail. Use a magnifying glass to look for cracks and replace them if you find a crack or swelling. Replace all shrouds at one time so you always know how old your rig is. Check the wire and end fittings on your winches in the same way and the move on to the rest of the running rigging. Look at each block (pulley) and make sure it runs smoothly and has no flat spots or burs on the sheaves. Make sure sheaves are properly sized by always having sheaves that are at least five times the size of the line passing over them. Look over lines and replace any that are worn, pulled or frayed. Check the line ends and reseize or burn the ends to prevent unravelling. It’s finally time to pay attention to the spars themselves. Remove the hardware after taking more photos. Thoroughly clean the spars. Sand all rough spots smooth and then sand the spar. According to David Marlow, there are three approaches to painting a spar. The one you choose will probably be determined by your skills and available equipment. As with most other jobs, the more complex one is the one that will give the best and longest lasting results. Take all safety precautions seriously. Painting in an unventilated space is very dangerous. Method 1. Dewax, degrease and clean the spars. Sand blast or sand the spars with 60 grit, clean up all dust, prime with zinc chromate, sand again with 220-grit, apply Awlgrip 545 gray epoxy primer,sand smooth, apply another coat of Awlgrip 545, sand smooth with 220 grit and finally apply two coats of Awlgrip White. Method 2. Dewax, degrease and clean the spars. Use the zinc chromate and Awlgrip 545 steps of Method 1 and then topcoat with 2 coats of two-part Interlux Perfection Poyurethane. Method 3. Dewax, degrease and clean the spars. Sand the spars with 60-grit and apply Interlux zinc chromate, clean up all dust, and apply Interlux sanding primer, or Brightside Primer, then topcoat with two coats of one-part Interlux Brightside Polyurethane. Now that everything is bright and shiny, put it all back together, checking your pictures frequently. Raise the mast carefully and tighten the turnbuckles slowly. Check out he noises. They may be important. When everything is up and fairly tight, lift a dinghy and find out if you did it right. Now aren’t you glad you aren’t a sailor with a great big mast?
It is the New Year of 2006 and time to consider the fitting out in a few months of those boats stored for the winter, as well as a general refurbishment of those yachts lucky enough to spend the winter in Southern climes. In a typical Spring updating, the emphasis is normally on cosmetic items and generic maintenance such as oil changes, fuel filter maintenance and so forth. Our timely tip for this year is to expand your work order just a bit and eliminate a fairly typical mid summer (usually at an inconvenient period) chore that is forced on us. Most of our reliable power plants depend on a variety of belts to drive water pumps, alternators and other devices that allow us to enjoy a fine style of on board life. Until they break, they are a red headed stepchild so to speak. Ignored where possible. These belts play a huge part in the safe and reliable operation of our yachts. They produce electricity from the alternators to keep our batteries up to snuff, water to keep everything cool and so forth. When they fail or their ability to do the job is compromised, it is at least noticeable and vacation altering if they fail completely. The cost of a new set of belts for everything on board, including a proper running in and readjustment after stretch is miniscule compared to the potential for damage, to say nothing of the inconvenience of losing precious leisure family time. Be sure they are readjusted after about 6-8 hours run maximum if you want the best they can be. Consider having your favorite mechanic or yard replace all of them and make sure they adjust them after a short run in period so they are set for a long trouble free run. If you meet resistance in way of "they look fine" why we just installed those in 89", consider a more energetic source of maintenance. |