bonding for lightning protection

[Mako2]

Is there a need to do special bonding to an aluminum pontoon boat for lightning protection, I have always had fiberglass boats which have a bonding system in addition to the negative ground. My initial thought is the boat itself is the bonding system but would welcome additional thoughts.

Thanks,
Mark

 

[dooma_Flatchy]

Re: bonding for lightning protection

I just installed some head/docking lights on my pontoon and I screwed the ground to the aluminum cross braces that the deck screws down to then I brushed liquid tape over them. No problems.

 

[Mako2]

Re: bonding for lightning protection

Thank you for the reply, I was actually referring to the lightning that accompanies thunder.

As a side note I believe you should not use the boat as your negative ground but rather run the negative leads back to the battery or negative bus bar.

Mark

 

[dooma_Flatchy]

Re: bonding for lightning protection

HAHA Sorry about that.. Thats what I get for skimming and not reading :redface:. I do have the light switch grounded through the battery.. You know I have never thought about lightning and my pontoon, I am very interested since I leave my toon in a boat slip. I will shut my mouth and watch the response of those that actually read the post:redface:

 

[tashasdaddy]

Re: bonding for lightning protection

if lightning gets that close, i don't think i will be around afterwards to worry about it.

 

[Silvertip]

Re: bonding for lightning protection

Actually it is not the lightning striking the boat that is the problem because the boat will shed the energy to the water. The problem arises in what is best called a sideways strike. Say you are holdiing your favorite graphite fishing rod that is dalso a very good lightning rod. Lightnight hits it, passes through your body then to the boat and now you are toast. While you will likely still be seriously injured or killed by lightning hitting the boat itself, your chances of survival are better if you are not in direct contact with the metal on the boat when it's hit. My rule of thumb is that if I see dark clouds and hear thunder in the distance, it's time to head for the dock -- rapidly.

 

[steelespike]

Re: bonding for lightning protection

Had a neighbor whose fiberglass sail boat, about 14ft, was struck. Burned holes along the waterline.Not much you can do about lightening.

 

[mrdude]

Re: bonding for lightning protection

DUDE.. if your aluminum boat gets hit by lightning you best hope no1's on it... the only chance you may have to avoid death by electricution is set you a 8" thick rubber pad down on a dry spot and pray.

 

[EGlideRider]

Re: bonding for lightning protection

DUDE.. if your aluminum boat gets hit by lightning you best hope no1's on it... the only chance you may have to avoid death by electricution is set you a 8" thick rubber pad down on a dry spot and pray.

Actually you would be better off touching the aluminum than you would sitting on a rubber pad. The aluminum boat has two advantages over a fiberglass one. One is that the aluminum boat will tend to remain the same electrical potential as the surrounding water and thus will not 'look' particularly attractive to a potential lighting strike.

The second is that the aluminum will act as a 'Faraday Shield' which means that if lighting does strike it, the current will mostly flow around passengers and through the metal.

As we all know, a car is a very safe place to be in an electrical storm. It is very safe, not due to the rubber tires, but due to it being a good 'Faraday Shield'. That is, if it is struck, the lightning will travel around the occupants and not through them. In fact, an occupant could be touching the metal and not be injured.

With all of this said, while the aluminum boat is safer than a fiberglass one, no boat is totally safe in an electrical storm. If I am in any small boat in an electrical storm, I am headiing towards the shore, powerlines, towers or bridges in an attempt to give a potential lighting strike an alternative path to the one through my body.

 

[Ripfence]

Re: bonding for lightning protection

Actually you would be better off touching the aluminum than you would sitting on a rubber pad. The aluminum boat has two advantages over a fiberglass one. One is that the aluminum boat will tend to remain the same electrical potential as the surrounding water and thus will not 'look' particularly attractive to a potential lighting strike.

The second is that the aluminum will act as a 'Faraday Shield' which means that if lighting does strike it, the current will mostly flow around passengers and through the metal.

As we all know, a car is a very safe place to be in an electrical storm. It is very safe, not due to the rubber tires, but due to it being a good 'Faraday Shield'. That is, if it is struck, the lightning will travel around the occupants and not through them. In fact, an occupant could be touching the metal and not be injured.

With all of this said, while the aluminum boat is safer than a fiberglass one, no boat is totally safe in an electrical storm. If I am in any small boat in an electrical storm, I am headiing towards the shore, powerlines, towers or bridges in an attempt to give a potential lighting strike an alternative path to the one through my body.

cool post, thanks for the info.

 

[mrdude]

Re: bonding for lightning protection

believe what you want fella's but i work with electricity often and electricity takes the fastest way to ground period... if your in its grounding path you most likely wont live to tell about it.. the shield talked about is similar to a tesla coil affect.. not a lightning strike.

 

[EGlideRider]

Re: bonding for lightning protection

I won't get into a pissing contest here so this is my last post for this thread.
As a retired electrical engineer, some of my duties were protecting electronics equipment from lightning.

There is absolutely no relationship between a Telsa Coil and a Faraday Shield.

 

[cribber]

Re: bonding for lightning protection

In a thunderstorm you want to have the lowest profile as possible while scooting it back to the ramp if ya get caught out on the water. Lightning tends to go for the tallest object so drop that bimini top all the way down if you can. I've been chased off the water many times here in central Florida when the seabreeze collisions occur in the afternoon.