Lightning Bonding

[Stillraining]

OK. I dont know whats going on but my first Post did not make the topic list so here it is again . I hope I can get more then one responce this time.Bonding Issue Ok I have an issue with my bonding system.First of all my bonding plate is not big enough so I have to figure out what to do there. It is only 3 x 9" right now. Also my mast has never been bonded to it, the chainplates however are, also the length of horizontal run from the main mast to the bonding plate is 20' and passes between both my fuel tanks which are fiberglass and 18 1" SS keel bolts, then under the gen set and engine to the bonding plate back at the shaft tube.I will post two pictures to show some of this.My concerns are1) The horizontal run is not a vertical one like every book suggests.2) The run would be laying on the bottom of the hull ( could it blow holes in it? )3) It would run between the built in fiberglass fuel tanks ( dosent seem to cool for the same reason )4) Past all the keel bolts, under the genset and engine. ( All atractive metels )5) Best way to increase, and secure a larger bonding plate and made out of what material? ( origional was only secured with 2-1/4" SS thru bolts about 5" center to center with no backing plate just small SS washers )All advice is welcome. ThanksPS: I am standing on the starboard fuel tank the port is opposite it.

 

[Dennis W.]

If this is a test

Stllraining, Maybe no one is sure how to answer!Dennis W.S/V FullSailed

 

[Ross]

Connect a number 2 cablefrom your starboard upper shroud

to the water by whatever method suits you. Or do nothing the odds are the same.

 

[Stillraining]

You were the one guy I

was hoping for more out of then that Ross

 

[jackhartjr]

I think what Ross is ...

...trying to say is this; lightning is a fickle thing, it might hit...it might not...some boats get hit with lightning suppresion systems and all sorts of 'stuff' is ruined...then boats without suppresion systems are hit and nothing is harmed. It is a crapshoot either way.Ross...did I hit your thoughts about right?Jack

 

[Ross]

Bingo! Sometimes trees are struck and blown

apart and other times there is only a slight mark on them. Sometimes the short tree takes the hit in the bottom of a valley while other trees farther up the slope are spared. On a beach with ten thousand people one might be hit or none get hit during a storm. There is little or no predictability.

 

[Alex]

Bond to the keel

Mine is bonded to the keel from the factory. There is a thick cable from the mast to a keel bolt.

 

[Don S/V ILLusion]

didn't like the previous answers?

nm

 

[Jadedcrew]

Still Raining

This looks like the third post from you on your bonding issue. I say get rid of it because it can only cause drag when sailing.I like Ross's answer. Its how I see lightning.

 

[Stillraining]

No I just find it a little sad that there is more intrest in the way someones wo

Im not concerned about preventing a strike, or the satisticts of what gets hit where. I was looking for the best way to protect my Family and the people aboard it from harm. I stated my concerns for all to see,fuel tanks, other metels that could generate leathel side currents ect. I was authentically asking others with more knowlage then I for their help. All is ok I will look elsewhere.Thanks to all. ScottAlex: Is your keel incapulated or not? Mine is and I was told buy one guy it would not do me any good.???

 

[Ross]

Stillraining, My first post was the most accurate that

anyone can give you. Giving the lightning a more or less straight path to ground is the best you can do and hope for it seems to jump to another path rather than follow a sharp bend. I have see evidence of a bolt jumping from a tall tree to a short tree or vice versa depending on whether the strike starts at the ground and goes up or starts from on high and comes down. We had a strike here at the house that did some strange things; it burst a bulb in a hanging light in the hall but didn't wreak the switch. It blew a fist size piece of concrete out of the driveway and that dented the steel rim on my son's car. and finally it followed a crack into the garage and knocked a can of fast plug cement over and caved in the bottom along the way it knocked the down spout extension flat for about a foot. I wasn't home when it hit so I can't say how loud it may have been. I live in a neighborhood of all brick rancher style houses on a straight level road. One of those nearly identical houses, all with one chimney, situate on 90 foot lots has been struck twice, one strike set it on fire, the other knocked some bricks off the chimney.

 

[Don S/V ILLusion]

Grounding

Please don't confuse "lack of interest" with lack of understanding your questions.Follow Ross's advice which is sound and realistic amd keep in mind the best ground you can install will do two things:1. provide a straight path to ground, and2. more than likely attract lightning strikes.An encapsulated keep is equivalent to one not encapsulated in terms of ground potential. It is capacitively coupled to water such that it provides the least reisistive path, the efficacy of which is superior to any ground plate which could blow apart easily if struck creating a nice view of the bottom, albeit temporary...

 

[CalebD]

Stillraining, it is a complex issue and more an art

than a science at the moment. There is a lot of information on the web on this topic that you should read and decide for yourself what course of action you want to take. Check out the article by the University of Florida linked on the page below and their other sources. We have a guy in our club who put a sheet of copper approx. 1' x 4' on the outside of his FRP hull near the mast boot to use as a grounding plate. He claimed (and he might be right) that all the boats in our anchorage have undersized grounding plates given the power of lightning. His theory, it would seem is to increase the area of the grounding plate in order for it to dissipate more quickly and evenly into the water. Most members of our club seemed to view this as a kind of curiosity.Sailboats and lightning are not a good mix and generally one should stay at the dock or mooring if there is activity nearby. This is not always possible though as lightning can come from localized and fast moving systems. We got caught out on a friends Mac 26S in the East River when a major lightning event came through. Several bolts each minute for about 15 minutes was pretty terrifying as we passed under first the Whitestone then Throgg's Neck bridge. Some of the bolts hit ground about a mile from our location. One of our crew advised we drop sail and hang out under a bridge until the storm let up but they do not tell you to stand under a tree on a golf course in the same conditions. Our captain just kept going and eventually we emerged into the Sound and the lightning had moved on. After I changed my underwear I thought how lucky we were as the Mac 26 has little in the way of bonding much less a grounding plate. There were few places to pull in and anchoring was unlikely in the deep, fast moving water.

 

[r.w.landau]

I am not sure but I know it was Nigel Calder

I thought it was Boat Maintenence but my guess is that this link would cover the issue of lightning.Nigel exlained the pros and cons of both schools. He explained grounding and bonding, batteries, and more...I am not sure this is the book that I have but it is packed away right now so I can't find it. I think this book would cover the same topics. This is a link to this chandlery at SailBoat Owners. You could alway call them and ask.http://shop.odayowners.com/books/detail-books.htm?fno=60&sku=35731&cat=1306This is not easy info to digest. It is pretty tech stuff that my take some further digging, but Nigel's was the easiest explaination I have read.Remember that salt water is a conductor. Fresh water is a totaly different story!Hope this helpedr.w.landau

 

[Ross]

CalebD, I was helping a friend move his Catalina 22

From Havre de Grace to Lauderic Creek near Aberdeen Proving Ground on a clear day a few years ago. We were about a thousand yards off shore when I saw a muddy geyser appear about 800 yards from our boat. I asked Larry if he thought that was a shell burst about the time we saw a second one and the Army's safety patrol boat bearing down on us to chase us out of the restricted area.Having artillary making muddy splashes when you can see the splash and hear the boom at close interval make lightning seem tame.

 

[CalebD]

Ross, isn't that what is called: target practice?

Which is fine and dandy as long as you are not the target! The downside is that if you get hit by a shell like that you are at least going swimming if you are lucky. With lightning it is a total crap shoot.

 

[r.w.landau]

Ross, Nigel doesn't cover that!

You may need to search your own references.r.w.landau

 

[sailaway78]

IMHO

I don't know whether bonding is or isn't a good thing. No one else seems to have a really good answer that is backed up by much more than supposition or a "this happened to someone I know" type answer. For myself, I think it can't hurt anything, even if it doesn't help. I have the chain plates, connected direct to the keel bolts, with a #2 cable. One on each side of the boat.

 

[Ross]

Caleb , If you get hit by someting like that you never know.

The old adage, " if your boat sinks , there you are!" "But if it gets blown out of the water , Where are you?"

 

[CalebD]

Life is about risks and managing them

Driving a car is dangerous and you will probably get into at least one accident in your life unless you are really lucky. This does not stop a lot of people from getting in their cars and driving after a few drinks. Similarly, boating is an inherently risky occupation. But boating near an artillary testing grounds sounds almost worse than boating in a lightning storm. Both situations should be avoided.r.w. - I think you mentioned Calder's book "Boatowner's Mechanical & Electrical Manual". I have the 2nd edition and there is some discussion about lightning in there worth reading.Again, link to Univ. of FL website on lightning and boating issues: http://www.thomson.ece.ufl.edu/lightning/SGEB17.html