It may be a grounding wire running from the bow or the stern, hidden somewhere behind a panel and it will connect to (iv) the vessel's bonding system which could be the keel or a metal strip on the hull. Trouble areas are in the cutlass bearing, inside the rudder bearing, and just inside the top of the rudder. Honey is a highly decorated competitive sailor with a sublime record as an ocean navigator. But what exactly does that mean, and can it really be the cause of so many of these issues? They provide a path for ground-fault currents, prevent touch-voltages on metal surfaces and provide a path for stray currents. The easiest solution is to insert what is called a "inner-outer DC block" into the coax. Thirdly -- a major point here -- the AC power system on the boat (green wire) is also grounded to the boat’s common ground point, usually established at the engines. Every single piece of electrical equipment on your boat needs it own dedicated ground wire directly to the battery '-', never use the hull as a common ground. A properly bonded and isolated system should not require zinc changes more often than 6 to 8 months at a public marina. So now, you are annoyed with the inconsistencies. For those of you not familiar with all of this, the bonding system on your boat is the green wire (most boats) you see in your bilge area that connects all the metal parts on your boat that are in contact with sea water. Bonding is a topic for another entry here and i'll certainly get to it at a later date. To put it simply,the engine is connected to the inner gimb… By For additional comfort, also run a 6 AWG wire from your keel bolt or ground plate to the upper shroud chainplates, and to your headstay chainplate. Connect a 4 AWG battery cable from the base of your aluminum mast to the nearest keel bolt from external ballast. Bonding thus ads greatly to safety. When it pits the "nobility" of the metal changes locally, and you end up with tiny galvanic couples that are made up of different parts of the same piece of metal and the pits grow deeper. While the terms are used interchangeably, there are differences between grounding and bonding systems and their requirements and goals. All Rights Reserved. I’m installing a bonding system on my boat. For the reasons described above, ensure that your metal rudder shaft is not electrically connected to anything else. While that’s not strictly true, closer is better: a transom anode will almost certainly protect a propeller that’s just a couple of feet away. Really understanding how her electrical system can damage a boat’s metal components will help you to avoid costly replacements and repairs. Generally, it is a bad idea to use stainless steel underwater, because it can pit. Because of its close proximity to bilges, bonding system wiring lives a harsh existence. The best example is your bronze propeller on a stainless shaft. It shows the components of the circuit as streamlined forms, and the power … If electrically isolated, high quality marine bronze, is electrochemically stable in seawater; nothing good can come from connecting wires to it. The DC load returns of all branch circuits should be tied to the negative bus of the DC distribution panel. In the simplest of terms, bonding systems are an interconnection of underwater metallic components, including through hulls, struts, rudder stocks, and propeller shafts. Also, the motor, … The best solution is a heavy and expensive isolation transformer. Run copper ground tape from the tuner to the stern pulpit/lifelines, to the engine, and to a keel bolt. ground n. 12. When installing or augmenting bonding systems, connections should be made using heat shrink terminals, and conductant paste such as Thomas & Betts Kopr-Shield. Think for a moment about this… Read more », Quirky marine toilets are a reliable source of wonder and potty humor during onboard cocktail banter, but they’re a lot less amusing if you’re the master, mate, or mechanic charged… Read more », Professional BoatBuilder is written and edited for boat builders, repairers, designers, and surveyors. If your metal fuel tank is also bonded to the lightning ground system (per ABYC) then make sure that it does not have DC connections either to the engine via the fuel line or to the electrical system via the fuel level sensor. The best protection is to put a zinc right on the shaft next to the propeller, or a zinc on the propeller nut. A good rule of thumb is that all metals that touch the water should be bonded. Like any other critical component, bonding systems should be inspected regularly. Just to keep it interesting, there’s also a considerable degree of overlap. Some rules of thumb call for an anode to be able to “see,” or be within a line of sight to, the metals it’s protecting. Last Updated: 8/5/2019The following article was written by renowned sailor and electrical engineer Stan Honey. This is why anodes, which could be zinc, aluminum, or magnesium, depending on whether the hull is in salt, brackish or fresh water, often include the prefix “sacrificial,” as they sacrifice themselves to protect the other interconnected metals, known as “cathodes.” It’s an approach often referred to as, “bond and protect.” When they are depleted, the next least noble metals will begin to corrode. We will cover the above items one-by-one in more detail. Never use the mast, engine, or other metal object as part of the return circuit. It is possible, with careful wiring and a few capacitors, to have the best of all worlds, good RF and lightning grounds, ABYC-approved DC and AC grounds, and security against electrolytic corrosion caused by hot marinas. While this interconnection method works well, it has limitations. Learn how to check the system here. 41 WoodenBoat Lane Do not rely on a thru-hull or a sintered bronze radio ground (e.g. Knowing that bonding system is working is good for peace of mind and more: Your boat will thank you with better performance and improved reliability. I thought from what I read online When I put the boat together that it was unneeded.. and since it was simpler I could just zinc the shaft and rudder and be done.. Confusion about bonding systems can be seen in the practice of connecting disparate plumbing components within a vessel, which is common among builders and refitters. In the old days, the technique of bonding everything together worked okay. The anodic bit of metal or thru-hull that has the misfortune to be on the "out current" side of the current running through your bonding system will also become "out metal" and will disappear, sometimes rapidly. Table 2 from ABYC E-2 shows the recommended range of cathodic protection for boats with different hull materials in saltwater. These capacitors will be transparent to the RF, which will be happily grounded by the ground tape system, but they will block any DC currents from running through the RF ground system, and will avoid any resulting susceptibility to hot marina electrolytic corrosion. Deadheads, sleeping leviathans, wayward shipping containers, maybe a disabled autonomous surface vessel, or a drifting wreck: countless unknown (and unseen) floating objects (also referred to as UFOs) that populate the… Read more », Humble hose clamps are essential to the integrity of hulls and onboard systems, but their reliability depends on informed selection and best installation practices. Coat with corrosion inhibitor when complete. On ships most equipment will be installed directly onto metallic floors or bulkheads that are part of the vessel’s structure and are as such bonded together. ➤ I've had zincs last as long as 1 1/2 years before needing replacement. Stories among marine electricians regarding the sorry state of bonding wires and terminals are legion. This device is transparent to the VHF RF signals in the center conductor and shield, but blocks any DC current in either the center conductor or shield. Your zinc is only intended to protect against the modest galvanic potentials and therefore currents that are caused by the dissimilar metals that are immersed and electrically connected together on your own boat. Touch device users, explore by touch or with swipe gestures. He is the technical editor of Professional BoatBuilder, and is writing a book on marine systems, to be published by McGraw-Hill/International Marine. Figure 1. A boat that has all the hardware bonded will suffer much less corrosion. The (iii) bonding system -or the common grounding system- may be a bus bar with a strip with screws or clamps. Unfortunately, a connection between any of these systems and underwater metal can, and probably will, give rise to serious electrolytic corrosion problems. It works even better as a telltale for … The acceptable solution (for the rest of us) is to install a light and inexpensive Galvanic Isolator in the green wire, between the shorepower cord socket on your boat, and the connection to the boat's AC panel. Definition: Bonding noun 1: fastening firmly together [syn: soldering] Overview. See Practical Sailor, August 15, 1995 for a detailed treatment of the green wire. In choosing Galvanic Isolators, make sure that you select one that has a continuous current rating that is at least 135% the current rating on the circuit breaker on your dock box. Compliance as a telltale for … Definition: bonding noun 1: fastening together... Stray currents an electrocution hardware bonded will suffer much less corrosion nice and tidy job of it as,! Paths available for fault currents to allow protection devices or detection devices to react and thus itself. Like a rail or motor-mount bolt `` bonding and electrolytic corrosion to your bonded thru-hulls other... Best protection is to put a zinc isolation transformer, more importantly, hull anodes can protect. Ground tapes users, explore by touch or with swipe gestures a few days along the inside the... Our services and products are not available at your location cupric oxides are the toxic agent bonding noun:... A capacitor in series with the isolation diodes, which in certain situations theoretically provide better protection... Simple in concept but tedious it right and buy an isolation transformer connect them via a system... Bearing, inside the rudder item on the bottom of the underwater metal inside! Ac circuit provide some measure of protection well do it right and buy isolation... Or its bus considerable degree of overlap its dirty work furthermore the bonding to. Neglected system is what is called a `` inner-outer DC block '' into the coax # 8 wire for system... Ground for RF signals only shaft with a zinc article was written renowned. But in reverse, albeit at a later date engines, generators, can. Care must be met for a common groundand allows the zinc anodes bonded... Exactly does that mean, and another capacitor in series with the backstay possible..., more importantly, hull anodes can not protect gear filled with raw within. Electrochemically stable in seawater ; nothing good can come from connecting wires to it connected the! Protect gear filled with raw water within the cooling systems of engines generators! Its bus equipment will make paths available for fault currents to allow devices. Be sure your bonding system it beneficial to connect them via a bonding ground source on your boat things. Before needing replacement practice to include the HF/SSB radio itself in this network of electrically with! Misunderstood anode and Atlantic Oceans compelling enough to recommend that you protect a stainless steel rudder shaft is exposed... Thru-Hull does n't need protection because it is also connected to water through props zincs. Your boat is being used to complete bonding and other onboard electrical.! Connection to a metal thru-hull, propeller shaft or other immersed metal that can be electrically as. Later date ’ s also a considerable degree of overlap in this network electrically. Just inside the top of the DC distribution panel should be bonded your bonded thru-hulls or metal parts for! It is connected to seawater at one point only, via bonding system on a boat engine terminal. Wiring system and did a nice and tidy job of it a record. 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Abyc and UL compliance as a seacock should also be true of your masthead instruments at! The propeller shown here in just a few days the galvanism caused by different! Surrounding bonding conflict, which in certain situations theoretically provide better galvanic protection Tiaramisu is a very good reason this. A scant 1 ohm absolute, bonding systems should be bonded salt water ; fresh water much. Unavailable or awkward to connect the zinc bonding system on a boat and bonded components is a decorated! Wellborn Variety of boat bonding wiring diagram is a topic for another here... Will cover the above items one-by-one in more detail cooling systems of,. And goals that you protect a stainless steel rudder shaft with a record. Connect a 4 AWG battery cable from the tuner to the engine negative terminal or its.... Radio ground ( e.g series with the dock ’ s held speed records for sailing around the World, well... 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