I have noticed there is 2 schools of thought about zinc's. Look under the boat that are hauled out, some have them some have 2, 3, and some don't have any. Any comments?
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What is your water like?
And some have none. The number is most likely a product of your water quality and the frequency of haul outs. The test is to look at your own and see how fast it is being chewed up. But for a quick answer, two seems a reasonable number. Logic: one will fall off and leave the second in tact.
And some have none. The number is most likely a product of your water quality and the frequency of haul outs. The test is to look at your own and see how fast it is being chewed up. But for a quick answer, two seems a reasonable number. Logic: one will fall off and leave the second in tact.
Electical should also be considered
If you leave your boat tied up to shore power you'll also go through them faster than if not. I keep mine on the grid when at dock and one 1" shaft zinc lasts about 2 months in a very electrically dirty marina (even with a galvanic isolator). On my old Catalina, which didn't get connected, two small zincs were enough to protect between bottom jobs (~2 years). I'm trying two shaft zincs right now to see if I get any better performance. Jim "Prospect"
If you leave your boat tied up to shore power you'll also go through them faster than if not. I keep mine on the grid when at dock and one 1" shaft zinc lasts about 2 months in a very electrically dirty marina (even with a galvanic isolator). On my old Catalina, which didn't get connected, two small zincs were enough to protect between bottom jobs (~2 years). I'm trying two shaft zincs right now to see if I get any better performance. Jim "Prospect"
A Whole Cartload .................................
............ should be about enough. If you are in salt water and your marina is as electrically dirty as ours is, you will find that as the zincs start to corrode away, they will loosen and be thrown of the shaft prematurely. One of my greatest fears (and I have so many, many of them when it comes to my boat) has been looking under the hull and seeing that I have NO zincs left. I have now gotten to the stage where I attach three zincs (H310) and use an over the side zinc plate. At the last haul out, the zincs were pretty eaten up but at least there was still something there after 12 months. I feel with this set up, I can now last one year without calling in a diver or doing an early haul-out. Regards, s/v Island Hunter
............ should be about enough. If you are in salt water and your marina is as electrically dirty as ours is, you will find that as the zincs start to corrode away, they will loosen and be thrown of the shaft prematurely. One of my greatest fears (and I have so many, many of them when it comes to my boat) has been looking under the hull and seeing that I have NO zincs left. I have now gotten to the stage where I attach three zincs (H310) and use an over the side zinc plate. At the last haul out, the zincs were pretty eaten up but at least there was still something there after 12 months. I feel with this set up, I can now last one year without calling in a diver or doing an early haul-out. Regards, s/v Island Hunter
zincs
by hanging one over the side , don't you attract more current? I am not to sure about any of this so I ask. should we be hanging more than one all around the boat?thanks
by hanging one over the side , don't you attract more current? I am not to sure about any of this so I ask. should we be hanging more than one all around the boat?thanks
cant have to many
I use two shaft zincs on my 40 and use shore power whenever I'm tied up. I usually have most of one left after 12-14 months, however I check them regularly and carry spares on board. They are cheaper to replace than thru hull fittings and props.
I use two shaft zincs on my 40 and use shore power whenever I'm tied up. I usually have most of one left after 12-14 months, however I check them regularly and carry spares on board. They are cheaper to replace than thru hull fittings and props.
Zincs
I just had the boat hauled out yesterday. My boat in in the ocean and have the electrical hooked up to electrical when not being used. I have three zincs on the shaft when the boat went into the water in May and ended up with about a third gone of two of the zincs and the other, which was on the boat when I bought it, was intact. I will replace the two that eaten away. At $6 bucks each it is a small investment. I might even splurge and replace the one that didn't show any signs of damage.
I just had the boat hauled out yesterday. My boat in in the ocean and have the electrical hooked up to electrical when not being used. I have three zincs on the shaft when the boat went into the water in May and ended up with about a third gone of two of the zincs and the other, which was on the boat when I bought it, was intact. I will replace the two that eaten away. At $6 bucks each it is a small investment. I might even splurge and replace the one that didn't show any signs of damage.
Can have too many
The most knowledgeable people in my marina with regard to electrical stuff all say one can overdo the number of zincs. On our 35 I use 1-inch shaft zincs a few inches in front of the strut. This allows for water to get into the cutlass. The zincs are changed every 6 months (every marina and boat will be different). If the zincs get burned up then the current will start looking for material in places such as the prop and engine bearings. Since we have a Max Prop this has to be protected at all costs. According to what I've been told, the Canadian and LA zincs are different in that the Canadian zincs rot from the outside whereas the LA zincs rot from the inside. I use the Canadian zincs. When installing zincs be sure and rap them with a hammer when tightening to get good contact and to ensure they don't get thrown while underway.
The most knowledgeable people in my marina with regard to electrical stuff all say one can overdo the number of zincs. On our 35 I use 1-inch shaft zincs a few inches in front of the strut. This allows for water to get into the cutlass. The zincs are changed every 6 months (every marina and boat will be different). If the zincs get burned up then the current will start looking for material in places such as the prop and engine bearings. Since we have a Max Prop this has to be protected at all costs. According to what I've been told, the Canadian and LA zincs are different in that the Canadian zincs rot from the outside whereas the LA zincs rot from the inside. I use the Canadian zincs. When installing zincs be sure and rap them with a hammer when tightening to get good contact and to ensure they don't get thrown while underway.
# depends on various factors.
Some based on your boat, others based on the marina. Electrical current can come from stray current in your boat, which you can fix, and also from other boats in your local, which you cannot. How often you have to repair you zincs depends on those factos. I have to replace my zinc about every 3 months. John, how may zincs do you keep on your shaft and how would you know if you have too many?
Some based on your boat, others based on the marina. Electrical current can come from stray current in your boat, which you can fix, and also from other boats in your local, which you cannot. How often you have to repair you zincs depends on those factos. I have to replace my zinc about every 3 months. John, how may zincs do you keep on your shaft and how would you know if you have too many?
Every 3 months seems high
Since my original two are still on my H340 four years later, with little erosion, and with shore power hooked up all the time. Wouldn't replacement every three months would a major problem in the marina. Okay, I'm in fresh water, but all the boats on my dock have continuous connections to shore power. Is the salt water the only difference?
Since my original two are still on my H340 four years later, with little erosion, and with shore power hooked up all the time. Wouldn't replacement every three months would a major problem in the marina. Okay, I'm in fresh water, but all the boats on my dock have continuous connections to shore power. Is the salt water the only difference?
Two Zincs on Shaft
For years I've kept two zincs on the prop shaft and the six month replacement period is based on what has worked in the past. I'm not a liveaboard and don't have the shore power connected to the ships electrical system except for a couple weeks per year. In the winter I use a construction grade 15-amp connector to the 30-amp shore power cord to connect two 60W electric heaters and one golden rod heater for under the engine. My reason for not connecting the boat to shore power is to avoid becoming a ground for the marina. The marine is checked regularly for "hot spots" and my slip area was okay the last time it was checked.
For years I've kept two zincs on the prop shaft and the six month replacement period is based on what has worked in the past. I'm not a liveaboard and don't have the shore power connected to the ships electrical system except for a couple weeks per year. In the winter I use a construction grade 15-amp connector to the 30-amp shore power cord to connect two 60W electric heaters and one golden rod heater for under the engine. My reason for not connecting the boat to shore power is to avoid becoming a ground for the marina. The marine is checked regularly for "hot spots" and my slip area was okay the last time it was checked.
Jim, once a month to once in two...
....and I'm referring to the zincs. It makes a huge difference in salt water, how 'hot' the docks are, liveaboards on the finger, etc. Basically, reason enough to have a diving service. One more little piece of operating overhead. However it is a high margin added service for the dive guys, so you have to keep 'em honest. Rick D.
....and I'm referring to the zincs. It makes a huge difference in salt water, how 'hot' the docks are, liveaboards on the finger, etc. Basically, reason enough to have a diving service. One more little piece of operating overhead. However it is a high margin added service for the dive guys, so you have to keep 'em honest. Rick D.
salt and steel
Yes, Jim, it has everything to do with salt. And steel. On the end tie next to me is a 100-foot steel motoryacht, a beautiful classic, which requires me to use double shaft zincs, one of which is rotated every three months. This doesn't seem excessive to me, because my previous experience is with a slip in Monterey where I had steel fishing trawlers on each side, and would burn through six zincs per year. Down there we also had to attach a cable to the shaft with a zinc brick which we'd lower over the side. We'd go through one of those per year as well.
Yes, Jim, it has everything to do with salt. And steel. On the end tie next to me is a 100-foot steel motoryacht, a beautiful classic, which requires me to use double shaft zincs, one of which is rotated every three months. This doesn't seem excessive to me, because my previous experience is with a slip in Monterey where I had steel fishing trawlers on each side, and would burn through six zincs per year. Down there we also had to attach a cable to the shaft with a zinc brick which we'd lower over the side. We'd go through one of those per year as well.
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