Cal 29 Grounding

During the last couple of years I've noticed that my zincs are corroding very quickly. After an inspection of my grounding system I discovered that all my electronics are grounded to my engine. My stays and shrouds have grounding wires on them but they're not connected together or to any common grounding path. I have 2 tear-drop zincs on the shaft and they typically last about 4 or 5 months tops. I'm thinking about adding a 3rd. Although, this rate of erosion seems rather quick to me. I have 2 thru-hull fittings that are grounded the rest are not. I understand there are two schools of thought on this issue, which is more ideal? For lightning protection purposes I'm not a big fan of connecting the thru-hull valves to the grounding system. I also found that my aluminum fuel tank is not grounded at all. The marine electronics book that I've been reading shows an immersed grounding plate or strip which connects to the entire electrical/rigging system. Perhaps the keel serves this purpose on some boats? I'd be curious to hear other opinions out there. Thanks, Frans Cal 2-29 Seattle, WA Hull# 946

Here is the long version of my opinion: http://l-36.com/bonding2.php The quick version is that you don't want to bond anything you don't have to. You do have to ground for: 1) Safety. If it is metal and near wiring, it must be grounded because the wire can become AC hot. Really,it can. 2) Bond to a zinc because dissimilar metals are bonded already for example a shaft and its prop are bonded so you need to bond a zinc to them as well. 3) Lightning. If you are in California like I am, you ignore this one. If you are in Florida, you are very concerned about it. But a lightning ground should not go to any other ground system and not to through hulls as if you get hit by lightning it can blow out the through hulls. Lightning grounding involves a plate on the outside of the hull near the mast and something similar to a battery cable connecting them together. Want to see what happens if your through hulls are grounded and you are hit by lightning: http://l-36.com/lightning_sinks_boat.php Back to your zincs. Probably the issue is that you don't have an isolator in your AC system. Get a digital voltmeter. Set it to mA. Connect one lead to your engine and one to a wire connected to a zinc hanging over the side in the water. Note the current. Then unplug your shore power. If it goes down, you have found your problem. Read the article. There are lots of things relating to the issue you have in it. Allen On Fri, Mar 22, 2013 at 8:36 PM, Frans <fr… [at] yahoo.com> wrote: > ** > > > During the last couple of years I've noticed that my zincs are corroding > very quickly. After an inspection of my grounding system I discovered that > all my electronics are grounded to my engine. My stays and shrouds have > grounding wires on them but they're not connected together or to any common > grounding path. I have 2 tear-drop zincs on the shaft and they typically > last about 4 or 5 months tops. I'm thinking about adding a 3rd. Although, > this rate of erosion seems rather quick to me. > > I have 2 thru-hull fittings that are grounded the rest are not. I > understand there are two schools of thought on this issue, which is more > ideal? For lightning protection purposes I'm not a big fan of connecting > the thru-hull valves to the grounding system. I also found that my aluminum > fuel tank is not grounded at all. > > The marine electronics book that I've been reading shows an immersed > grounding plate or strip which connects to the entire electrical/rigging > system. Perhaps the keel serves this purpose on some boats? > > I'd be curious to hear other opinions out there. > > Thanks, > > Frans > Cal 2-29 > Seattle, WA > Hull# 946 > > >

Lightning hits boat with bonded through hulls. [image: Inline image 1] On Fri, Mar 22, 2013 at 11:04 PM, Allen Edwards <al… [at] gmail.com>wrote: > > Here is the long version of my opinion: > http://l-36.com/bonding2.php > > The quick version is that you don't want to bond anything you don't have > to. You do have to ground for: > 1) Safety. If it is metal and near wiring, it must be grounded because > the wire can become AC hot. Really,it can. > 2) Bond to a zinc because dissimilar metals are bonded already for example > a shaft and its prop are bonded so you need to bond a zinc to them as well. > 3) Lightning. If you are in California like I am, you ignore this one. > If you are in Florida, you are very concerned about it. But a lightning > ground should not go to any other ground system and not to through hulls as > if you get hit by lightning it can blow out the through hulls. Lightning > grounding involves a plate on the outside of the hull near the mast and > something similar to a battery cable connecting them together. > > Want to see what happens if your through hulls are grounded and you are > hit by lightning: > http://l-36.com/lightning_sinks_boat.php > > Back to your zincs. Probably the issue is that you don't have an isolator > in your AC system. Get a digital voltmeter. Set it to mA. Connect one > lead to your engine and one to a wire connected to a zinc hanging over the > side in the water. Note the current. Then unplug your shore power. If it > goes down, you have found your problem. > > Read the article. There are lots of things relating to the issue you have > in it. > > Allen > > > > > On Fri, Mar 22, 2013 at 8:36 PM, Frans <fr… [at] yahoo.com> wrote: > >> ** >> >> >> During the last couple of years I've noticed that my zincs are corroding >> very quickly. After an inspection of my grounding system I discovered that >> all my electronics are grounded to my engine. My stays and shrouds have >> grounding wires on them but they're not connected together or to any common >> grounding path. I have 2 tear-drop zincs on the shaft and they typically >> last about 4 or 5 months tops. I'm thinking about adding a 3rd. Although, >> this rate of erosion seems rather quick to me. >> >> I have 2 thru-hull fittings that are grounded the rest are not. I >> understand there are two schools of thought on this issue, which is more >> ideal? For lightning protection purposes I'm not a big fan of connecting >> the thru-hull valves to the grounding system. I also found that my aluminum >> fuel tank is not grounded at all. >> >> The marine electronics book that I've been reading shows an immersed >> grounding plate or strip which connects to the entire electrical/rigging >> system. Perhaps the keel serves this purpose on some boats? >> >> I'd be curious to hear other opinions out there. >> >> Thanks, >> >> Frans >> Cal 2-29 >> Seattle, WA >> Hull# 946 >> >> >> > >

Allen, We do get an occasional lightening storm down here in Sow Cal. And consider this, by grounding the thru hulls and blowing them out, it would rapidly put out any on board fire started by the lightning. On the other hand, maybe that's why some of us carry fire extinguishers? Jerry of Shpritz From: Allen Edwards <al… [at] gmail.com> To: Ca… [at] yahoogroups.com Sent: Friday, March 22, 2013 11:04 PM Subject: Re: [Cal_Boats] Cal 29 Grounding Here is the long version of my opinion:http://l-36.com/bonding2.php The quick version is that you don't want to bond anything you don't have to. You do have to ground for: 1) Safety. If it is metal and near wiring, it must be grounded because the wire can become AC hot. Really,it can. 2) Bond to a zinc because dissimilar metals are bonded already for example a shaft and its prop are bonded so you need to bond a zinc to them as well. 3) Lightning. If you are in California like I am, you ignore this one. If you are in Florida, you are very concerned about it. But a lightning ground should not go to any other ground system and not to through hulls as if you get hit by lightning it can blow out the through hulls. Lightning grounding involves a plate on the outside of the hull near the mast and something similar to a battery cable connecting them together. Want to see what happens if your through hulls are grounded and you are hit by lightning: http://l-36.com/lightning_sinks_boat.php Back to your zincs. Probably the issue is that you don't have an isolator in your AC system. Get a digital voltmeter. Set it to mA. Connect one lead to your engine and one to a wire connected to a zinc hanging over the side in the water. Note the current. Then unplug your shore power. If it goes down, you have found your problem. Read the article. There are lots of things relating to the issue you have in it. Allen On Fri, Mar 22, 2013 at 8:36 PM, Frans <fr… [at] yahoo.com> wrote: > >During the last couple of years I've noticed that my zincs are corroding very quickly. After an inspection of my grounding system I discovered that all my electronics are grounded to my engine. My stays and shrouds have grounding wires on them but they're not connected together or to any common grounding path. I have 2 tear-drop zincs on the shaft and they typically last about 4 or 5 months tops. I'm thinking about adding a 3rd. Although, this rate of erosion seems rather quick to me. > >I have 2 thru-hull fittings that are grounded the rest are not. I understand there are two schools of thought on this issue, which is more ideal? For lightning protection purposes I'm not a big fan of connecting the thru-hull valves to the grounding system. I also found that my aluminum fuel tank is not grounded at all. > >The marine electronics book that I've been reading shows an immersed grounding plate or strip which connects to the entire electrical/rigging system. Perhaps the keel serves this purpose on some boats? > >I'd be curious to hear other opinions out there. > >Thanks, > >Frans >Cal 2-29 >Seattle, WA >Hull# 946 > >

On a list of 51 states (includes DC) California is at the bottom in the number of lightning strikes. We get them up here as well but my lightning strategy is don't go sailing when there is lightning in the forecast. That strategy apparently doesn't work in Florida where most boats get hit at some point as I recall. I personally have never heard of a boat being hit by lightning in California but it probably has happened. Allen On Fri, Mar 22, 2013 at 11:13 PM, Gerald Sobel <so… [at] yahoo.com>wrote: > ** > > > Allen, > We do get an occasional lightening storm down here in Sow Cal. And > consider this, by grounding the thru hulls and blowing them out, it would > rapidly put out any on board fire started by the lightning. > > On the other hand, maybe that's why some of us carry fire extinguishers? > > Jerry of Shpritz > ------------------------------ > *From:* Allen Edwards <al… [at] gmail.com> > *To:* Ca… [at] yahoogroups.com > *Sent:* Friday, March 22, 2013 11:04 PM > *Subject:* Re: [Cal_Boats] Cal 29 Grounding > > > > Here is the long version of my opinion: > http://l-36.com/bonding2.php > > The quick version is that you don't want to bond anything you don't have > to. You do have to ground for: > 1) Safety. If it is metal and near wiring, it must be grounded because > the wire can become AC hot. Really,it can. > 2) Bond to a zinc because dissimilar metals are bonded already for example > a shaft and its prop are bonded so you need to bond a zinc to them as well. > 3) Lightning. If you are in California like I am, you ignore this one. > If you are in Florida, you are very concerned about it. But a lightning > ground should not go to any other ground system and not to through hulls as > if you get hit by lightning it can blow out the through hulls. Lightning > grounding involves a plate on the outside of the hull near the mast and > something similar to a battery cable connecting them together. > > Want to see what happens if your through hulls are grounded and you are > hit by lightning: > http://l-36.com/lightning_sinks_boat.php > > Back to your zincs. Probably the issue is that you don't have an isolator > in your AC system. Get a digital voltmeter. Set it to mA. Connect one > lead to your engine and one to a wire connected to a zinc hanging over the > side in the water. Note the current. Then unplug your shore power. If it > goes down, you have found your problem. > > Read the article. There are lots of things relating to the issue you have > in it. > > Allen > > > > > On Fri, Mar 22, 2013 at 8:36 PM, Frans <fr… [at] yahoo.com> wrote: > > ** > > During the last couple of years I've noticed that my zincs are corroding > very quickly. After an inspection of my grounding system I discovered that > all my electronics are grounded to my engine. My stays and shrouds have > grounding wires on them but they're not connected together or to any common > grounding path. I have 2 tear-drop zincs on the shaft and they typically > last about 4 or 5 months tops. I'm thinking about adding a 3rd. Although, > this rate of erosion seems rather quick to me. > > I have 2 thru-hull fittings that are grounded the rest are not. I > understand there are two schools of thought on this issue, which is more > ideal? For lightning protection purposes I'm not a big fan of connecting > the thru-hull valves to the grounding system. I also found that my aluminum > fuel tank is not grounded at all. > > The marine electronics book that I've been reading shows an immersed > grounding plate or strip which connects to the entire electrical/rigging > system. Perhaps the keel serves this purpose on some boats? > > I'd be curious to hear other opinions out there. > > Thanks, > > Frans > Cal 2-29 > Seattle, WA > Hull# 946 > > > > > >

It hapens up here on Lake Erie and I have seen its results. While sailing in the Mills race a Lake Erie ass kicker blew up with out much of a warning, high winds, rain ,and lightning andhigh seas. We got most of the sails down but lost a spinaker tore the main and a stasail, the boat to our port and a100yards off wasent as luckey as lightning struck his mast and shot his spreaders like arrows, his stays held but his mast was doing a dance, he made it into Put in bay and all his electronics were cooked. From: Allen Edwards <al… [at] gmail.com> To: Cal_Boats <Ca… [at] yahoogroups.com> Sent: Sat, Mar 23, 2013 11:51 am Subject: Re: [Cal_Boats] Cal 29 Grounding On a list of 51 states (includes DC) California is at the bottom in the number of lightning strikes. We get them up here as well but my lightning strategy is don't go sailing when there is lightning in the forecast. That strategy apparently doesn't work in Florida where most boats get hit at some point as I recall. I personally have never heard of a boat being hit by lightning in California but it probably has happened. Allen On Fri, Mar 22, 2013 at 11:13 PM, Gerald Sobel <so… [at] yahoo.com> wrote: Allen, We do get an occasional lightening storm down here in Sow Cal. And consider this, by grounding the thru hulls and blowing them out, it would rapidly put out any on board fire started by the lightning. On the other hand, maybe that's why some of us carry fire extinguishers? Jerry of Shpritz From: Allen Edwards <al… [at] gmail.com> To: Ca… [at] yahoogroups.com Sent: Friday, March 22, 2013 11:04 PM Subject: Re: [Cal_Boats] Cal 29 Grounding Here is the long version of my opinion: http://l-36.com/bonding2.php The quick version is that you don't want to bond anything you don't have to. You do have to ground for: 1) Safety. If it is metal and near wiring, it must be grounded because the wire can become AC hot. Really,it can. 2) Bond to a zinc because dissimilar metals are bonded already for example a shaft and its prop are bonded so you need to bond a zinc to them as well. 3) Lightning. If you are in California like I am, you ignore this one. If you are in Florida, you are very concerned about it. But a lightning ground should not go to any other ground system and not to through hulls as if you get hit by lightning it can blow out the through hulls. Lightning grounding involves a plate on the outside of the hull near the mast and something similar to a battery cable connecting them together. Want to see what happens if your through hulls are grounded and you are hit by lightning: http://l-36.com/lightning_sinks_boat.php Back to your zincs. Probably the issue is that you don't have an isolator in your AC system. Get a digital voltmeter. Set it to mA. Connect one lead to your engine and one to a wire connected to a zinc hanging over the side in the water. Note the current. Then unplug your shore power. If it goes down, you have found your problem. Read the article. There are lots of things relating to the issue you have in it. Allen On Fri, Mar 22, 2013 at 8:36 PM, Frans <fr… [at] yahoo.com> wrote: During the last couple of years I've noticed that my zincs are corroding very quickly. After an inspection of my grounding system I discovered that all my electronics are grounded to my engine. My stays and shrouds have grounding wires on them but they're not connected together or to any common grounding path. I have 2 tear-drop zincs on the shaft and they typically last about 4 or 5 months tops. I'm thinking about adding a 3rd. Although, this rate of erosion seems rather quick to me. I have 2 thru-hull fittings that are grounded the rest are not. I understand there are two schools of thought on this issue, which is more ideal? For lightning protection purposes I'm not a big fan of connecting the thru-hull valves to the grounding system. I also found that my aluminum fuel tank is not grounded at all. The marine electronics book that I've been reading shows an immersed grounding plate or strip which connects to the entire electrical/rigging system. Perhaps the keel serves this purpose on some boats? I'd be curious to hear other opinions out there. Thanks, Frans Cal 2-29 Seattle, WA Hull# 946

We once did an overnight race on the Chesapeake and if you added up all the lightning I'd seen growing up in West Texas and then 20+ years on the east coast of Maryland, I'd swear I saw more in that one night. It was literally like a disco out there and 2 boats did get hit. Both lost electronics but neither sank. One boat was less than 1/4 mile from us and we saw it get hit. A couple of minutes after that I actually felt a tingle thru the wheel that really freaked me out. I had some diving gloves aboard and put them on just to make me feel better LOL. It was squall after squall. It'd blow stink for 15 min to 1/2 hr and then be dead friggin' calm, blow stink, dead calm. It was the hardest race we'd ever done. Tested all our skills and stamina. We were on the last leg up the St Mary's river when one of my crew did the math and said the only way we're gonna finish under the 21 hr time limit is if another squall comes thru and we don't have to tack. So this Irish girl we had on board starts a chant "we want thunder we want rain" and we were all so tired by then we just laughed and went along with it and sure enough another squall blew in and we quickly hardened up and shot toward the finish line . . . . well . . just like it had done all night the squall blew thru and time ran out 200 yards from the finish line. Only one boat felt worse than we did as they were only 100 yrds from the line. Paul From: Allen Edwards <al… [at] gmail.com> To: Cal_Boats <Ca… [at] yahoogroups.com> Sent: Sat, Mar 23, 2013 11:51 am Subject: Re: [Cal_Boats] Cal 29 Grounding On a list of 51 states (includes DC) California is at the bottom in the number of lightning strikes. We get them up here as well but my lightning strategy is don't go sailing when there is lightning in the forecast. That strategy apparently doesn't work in Florida where most boats get hit at some point as I recall. I personally have never heard of a boat being hit by lightning in California but it probably has happened. Allen On Fri, Mar 22, 2013 at 11:13 PM, Gerald Sobel <so… [at] yahoo.com> wrote: Allen, We do get an occasional lightening storm down here in Sow Cal. And consider this, by grounding the thru hulls and blowing them out, it would rapidly put out any on board fire started by the lightning. On the other hand, maybe that's why some of us carry fire extinguishers? Jerry of Shpritz From: Allen Edwards <al… [at] gmail.com> To: Ca… [at] yahoogroups.com Sent: Friday, March 22, 2013 11:04 PM Subject: Re: [Cal_Boats] Cal 29 Grounding Here is the long version of my opinion: http://l-36.com/bonding2.php The quick version is that you don't want to bond anything you don't have to. You do have to ground for: 1) Safety. If it is metal and near wiring, it must be grounded because the wire can become AC hot. Really,it can. 2) Bond to a zinc because dissimilar metals are bonded already for example a shaft and its prop are bonded so you need to bond a zinc to them as well. 3) Lightning. If you are in California like I am, you ignore this one. If you are in Florida, you are very concerned about it. But a lightning ground should not go to any other ground system and not to through hulls as if you get hit by lightning it can blow out the through hulls. Lightning grounding involves a plate on the outside of the hull near the mast and something similar to a battery cable connecting them together. Want to see what happens if your through hulls are grounded and you are hit by lightning: http://l-36.com/lightning_sinks_boat.php Back to your zincs. Probably the issue is that you don't have an isolator in your AC system. Get a digital voltmeter. Set it to mA. Connect one lead to your engine and one to a wire connected to a zinc hanging over the side in the water. Note the current. Then unplug your shore power. If it goes down, you have found your problem. Read the article. There are lots of things relating to the issue you have in it. Allen On Fri, Mar 22, 2013 at 8:36 PM, Frans <fr… [at] yahoo.com> wrote: During the last couple of years I've noticed that my zincs are corroding very quickly. After an inspection of my grounding system I discovered that all my electronics are grounded to my engine. My stays and shrouds have grounding wires on them but they're not connected together or to any common grounding path. I have 2 tear-drop zincs on the shaft and they typically last about 4 or 5 months tops. I'm thinking about adding a 3rd. Although, this rate of erosion seems rather quick to me. I have 2 thru-hull fittings that are grounded the rest are not. I understand there are two schools of thought on this issue, which is more ideal? For lightning protection purposes I'm not a big fan of connecting the thru-hull valves to the grounding system. I also found that my aluminum fuel tank is not grounded at all. The marine electronics book that I've been reading shows an immersed grounding plate or strip which connects to the entire electrical/rigging system. Perhaps the keel serves this purpose on some boats? I'd be curious to hear other opinions out there. Thanks, Frans Cal 2-29 Seattle, WA Hull# 946

On 3/23/2013 4:01 PM, pw… [at] aol.com wrote: > > > We once did an overnight race on the Chesapeake and if you added up > all the lightning I'd seen growing up in West Texas and then 20+ years > on the east coast of Maryland, I'd swear I saw more in that one night. A couple years ago we were bringing our schooner into Alpena, MI as weather was approaching from the west. Of course, the squall hit just as we entered the mouth of the river.They always do. The rain came down in solid sheets. But what worried me the most was that the lightning flash and the sound were simultaneous. We were too busy trying to moor the boat in all that mess to have much time to fret over it but you really can't ignore serious lightning when it's right overhead. You just can't do anything about it. Chris Campbell

Hey thanks Allen, The lack of galvanic isolator was the issue. I have 40mA stray current exiting the boat via the shaft. When I turn shore power off the multimeter reading goes to zero. I'm going to see if the galvanic isolator helps. Thanks again, Frans --- In Ca… [at] yahoogroups.com, Allen Edwards <allen.p.edwards@...> wrote: > > Here is the long version of my opinion: > http://l-36.com/bonding2.php > > The quick version is that you don't want to bond anything you don't have > to. You do have to ground for: > 1) Safety. If it is metal and near wiring, it must be grounded because the > wire can become AC hot. Really,it can. > 2) Bond to a zinc because dissimilar metals are bonded already for example > a shaft and its prop are bonded so you need to bond a zinc to them as well. > 3) Lightning. If you are in California like I am, you ignore this one. If > you are in Florida, you are very concerned about it. But a lightning > ground should not go to any other ground system and not to through hulls as > if you get hit by lightning it can blow out the through hulls. Lightning > grounding involves a plate on the outside of the hull near the mast and > something similar to a battery cable connecting them together. > > Want to see what happens if your through hulls are grounded and you are hit > by lightning: > http://l-36.com/lightning_sinks_boat.php > > Back to your zincs. Probably the issue is that you don't have an isolator > in your AC system. Get a digital voltmeter. Set it to mA. Connect one > lead to your engine and one to a wire connected to a zinc hanging over the > side in the water. Note the current. Then unplug your shore power. If it > goes down, you have found your problem. > > Read the article. There are lots of things relating to the issue you have > in it. > > Allen > > > > > On Fri, Mar 22, 2013 at 8:36 PM, Frans <franssell@...> wrote: > > > ** > > > > > > During the last couple of years I've noticed that my zincs are corroding > > very quickly. After an inspection of my grounding system I discovered that > > all my electronics are grounded to my engine. My stays and shrouds have > > grounding wires on them but they're not connected together or to any common > > grounding path. I have 2 tear-drop zincs on the shaft and they typically > > last about 4 or 5 months tops. I'm thinking about adding a 3rd. Although, > > this rate of erosion seems rather quick to me. > > > > I have 2 thru-hull fittings that are grounded the rest are not. I > > understand there are two schools of thought on this issue, which is more > > ideal? For lightning protection purposes I'm not a big fan of connecting > > the thru-hull valves to the grounding system. I also found that my aluminum > > fuel tank is not grounded at all. > > > > The marine electronics book that I've been reading shows an immersed > > grounding plate or strip which connects to the entire electrical/rigging > > system. Perhaps the keel serves this purpose on some boats? > > > > I'd be curious to hear other opinions out there. > > > > Thanks, > > > > Frans > > Cal 2-29 > > Seattle, WA > > Hull# 946 > > > > > > >

Make sure you are using a marine battery charger. The isolator should solve the stray current issue. A transformer is better, but they are very expensive and probably not necessary. The only issue with the isolator that I am aware of is that they can fail and then you are back to having stray current. I think some have lights to indicate if they are OK. Allen On Sun, Mar 31, 2013 at 9:08 PM, Frans <fr… [at] yahoo.com> wrote: > ** > > > Hey thanks Allen, > > The lack of galvanic isolator was the issue. I have 40mA stray current > exiting the boat via the shaft. When I turn shore power off the multimeter > reading goes to zero. > > I'm going to see if the galvanic isolator helps. > > Thanks again, > > Frans > > --- In Ca… [at] yahoogroups.com, Allen Edwards <allen.p.edwards@...> > wrote: > > > > Here is the long version of my opinion: > > http://l-36.com/bonding2.php > > > > The quick version is that you don't want to bond anything you don't have > > to. You do have to ground for: > > 1) Safety. If it is metal and near wiring, it must be grounded because > the > > wire can become AC hot. Really,it can. > > 2) Bond to a zinc because dissimilar metals are bonded already for > example > > a shaft and its prop are bonded so you need to bond a zinc to them as > well. > > 3) Lightning. If you are in California like I am, you ignore this one. If > > you are in Florida, you are very concerned about it. But a lightning > > ground should not go to any other ground system and not to through hulls > as > > if you get hit by lightning it can blow out the through hulls. Lightning > > grounding involves a plate on the outside of the hull near the mast and > > something similar to a battery cable connecting them together. > > > > Want to see what happens if your through hulls are grounded and you are > hit > > by lightning: > > http://l-36.com/lightning_sinks_boat.php > > > > Back to your zincs. Probably the issue is that you don't have an isolator > > in your AC system. Get a digital voltmeter. Set it to mA. Connect one > > lead to your engine and one to a wire connected to a zinc hanging over > the > > side in the water. Note the current. Then unplug your shore power. If it > > goes down, you have found your problem. > > > > Read the article. There are lots of things relating to the issue you have > > in it. > > > > Allen > > > > > > > > > > On Fri, Mar 22, 2013 at 8:36 PM, Frans <franssell@...> wrote: > > > > > ** > > > > > > > > > During the last couple of years I've noticed that my zincs are > corroding > > > very quickly. After an inspection of my grounding system I discovered > that > > > all my electronics are grounded to my engine. My stays and shrouds have > > > grounding wires on them but they're not connected together or to any > common > > > grounding path. I have 2 tear-drop zincs on the shaft and they > typically > > > last about 4 or 5 months tops. I'm thinking about adding a 3rd. > Although, > > > this rate of erosion seems rather quick to me. > > > > > > I have 2 thru-hull fittings that are grounded the rest are not. I > > > understand there are two schools of thought on this issue, which is > more > > > ideal? For lightning protection purposes I'm not a big fan of > connecting > > > the thru-hull valves to the grounding system. I also found that my > aluminum > > > fuel tank is not grounded at all. > > > > > > The marine electronics book that I've been reading shows an immersed > > > grounding plate or strip which connects to the entire > electrical/rigging > > > system. Perhaps the keel serves this purpose on some boats? > > > > > > I'd be curious to hear other opinions out there. > > > > > > Thanks, > > > > > > Frans > > > Cal 2-29 > > > Seattle, WA > > > Hull# 946 > > > > > > > > > > > > > >