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Old 10-08-2012, 03:08   #31
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Re: Lightning Strike Damage Details Needed

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Originally Posted by Celestialsailor View Post
Kinda makes ya ponder what would happen if she read all her prior posts. Perhaps that would attract a lightning strike!...

Be nice to her, seriously we need a control group. Lightning is fickle. Take a look at the radio amateur link in my above post. If you read through that you will find the statement that if you do not do everything exactly right, the protection applied can be worse than nothing.
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Old 10-08-2012, 07:30   #32
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Re: Lightning Strike Damage Details Needed

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Be nice to her, seriously we need a control group. Lightning is fickle. Take a look at the radio amateur link in my above post. If you read through that you will find the statement that if you do not do everything exactly right, the protection applied can be worse than nothing.
There already is a "control group" and that is taken into account by default in actuarial studies. A few cruisers relating personal accounts (particularly accounts of not being struck by lightning) will not provide any data valid for drawing conclusions.

All commercial radio towers, transmitters, office buildings, etc have bonding systems in place to lead a strike to ground to prevent structural damage and personal injury. Most likely, your house is similarly bonded. These installations are written in building codes and mandated by governments and insurance. This collusion of building engineers, governments and insurance companies working to actively attract lightning strikes and cause systemic damage to the nation's infrastructure seems like a strange conspiracy and scam to me.

To not take similar measures on a boat is a personal choice. To present oneself as a highly experienced expert in the area and tell others it is dangerous to take these measures is irresponsible.

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Old 10-08-2012, 07:42   #33
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Re: Lightning Strike Damage Details Needed

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Originally Posted by colemj View Post
.......
To not take similar measures on a boat is a personal choice. To present oneself as a highly experienced expert in the area and tell others it is dangerous to take these measures is irresponsible.

Mark
yep, +1
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Old 10-08-2012, 07:49   #34
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Re: Lightning Strike Damage Details Needed

i do not ADVISE people to do ANYTHING-- why dont you guys READ the posts instead of INTERPRET them--anyone trying to interpret someone else's words when written or spoken is asking to not understand the content. i say exactly what i mean. perhaps if you go back to READ the posts you might understand the words better.

i suggest what works for me.
i also state the results of folks i know being hit ---is actual damage done. not theory when the request was for actual damage done.
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Old 10-08-2012, 08:07   #35
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Re: Lightning Strike Damage Details Needed

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i do not ADVISE people to do ANYTHING-- why dont you guys READ the posts instead of INTERPRET them--anyone trying to interpret someone else's words when written or spoken is asking to not understand the content. i say exactly what i mean. perhaps if you go back to READ the posts you might understand the words better.
"is it not FAIR to say the alleged protetion devices attract lightning?? too bad--THEY DO JUST THAT."

"the alleged protection dreamed up by the vendors for keeping damage minimal doesnt work and does attract the bolts to your allegedly protected floating lightning rod."

"more damage is incurred WITH alleged protection than without"

"i gave you REALITY from REAL TIME experiences- take it or leave it-- protect your boat so mine is safer."

"if you dont like my answers--GO SAILING to learn reality.i havelost any respect i may have had for those who cannot understand the actualities of being there and knowing the souls who were hit. bad advice???? SAIL IN IT-- then you will see how bad the advice is."

"it is from ACTUAL experience, not statistics, which are skewed by insurance companies to promote their scams."

"i take the example of those being destroyed by hits --they are the "protected" (BY LIGHTNING ATTRACTORS) boats"


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Old 10-08-2012, 08:34   #36
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Re: Lightning Strike Damage Details Needed

A sailor could make a cost benefit decision based on where they sail. Here is a site that shows where lightening strikes occur in the world.
http://science.nasa.gov/science-news/science-at-nasa/2001/ast05dec_1/

In Florida, for example, the Florida Sea Grant estimated that lightning can be expected to hit from four to twenty percent of moored sailboats per year and that cruising sailboats typically get hit at least one time during their lifetimes.
http://www.sailingbreezes.com/sailing_breezes_current/articles/Sept03/lightning.htm

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Old 10-08-2012, 09:16   #37
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Re: Lightning Strike Damage Details Needed

During the decades I was in a boatbuilding project (3 separate ones), I read hundreds of books, thousands of monthlys, and even paid for research papers on a wide variety of subjects boat related... including this one. The jury was in 25+ years ago on this, and therefore, it seldom gets discussed except by the "gravity doesn't really exist" group.

Lightning is the #1 killer of all natural disasters on the planet. It is the fact that it is SO common, and kills one at the time, that has it off of the national news. This is as true on boats.

Thousands of boats get hit yearly, often with catastrophic results. I have known over 25 people who had their boats hit, (many within sight), but only a few were hit when they were on the boat. I have, however read of hundreds more! The important thing is that like wearing seatbelts, there is a way to improve your odds of survival X100...

Its not controversial, its common sense!



As far as lightning protection... Well it is a fickle thing, but we CAN drastically improve our odds against a total melt down, or driving the mast through the bottom of the boat!

Seatbelts don't prevent car wrecks, nor does a "Lightning Protection" System protect you from lightning. Never claimed to. Both, however, improves our odds of survival X100 or more!

If you are hit, lightning WILL then go to ground, either through the hull, catastrophically through the metal drivetrain and through hulls, or "hopefully", along the path that WE provide. This is the only given. IF YOU ARE HIT, IT WILL THEN GO TO GROUND!!! Only an idiot thinks that after hitting the mast head, the bolt would get to the mast base, and just stop there...

Statistical evidence from a very small sample, (like ourselves and the folks we know personally), is meaningless! To be valid... It has to be the scientifically accumulated evidence, compiled by thousands of the world's marine meteorologist, using tens of thousands of reports as a sample, over 20+ years... The jury has been in on this for decades!

Here's how to improve your odds exponentially:

Protecting electronics can be done "just a bit", by unplugging things, or taken to extremes, put spare hand held GPS type devices in a "Faraday cage", but this gets really iffy and of diminishing returns. I do carry a spare hand held GPS or two, away from metal, but if you take a BIG one, it is quite possible that ALL electronics will be fried. Lightning varies 1000%, and there are NO guarantees, EXCEPT that: "IF it hits your mast, it WILL then go to ground".

Setting as a goal, a lesser more reasonable level of protection... #1 You need a pointed lightning rod on the mast.

Then, GROUND THE MAST IN A DIRECT ROUTE WITH COPPER. Copper is MANY times better at conducting electricity, where as SS is quite poor. AVOID SHARP BENDS!

Searunners, like mine, are quite good in this respect. Look at my huge "00" grounding wire coming out of the mast. Being copper, its conductivity is roughly equivalent to the entire aluminum mast! Its through bolted, and just like other important connections, including batteries, I CRIMP, then "SOLDER" the crimp, for a perfect connection, and then I HEAT SHRINK the lug to wire interface. Even if the solder is melted by a direct hit, it remains crimped, and until then, the solder keeps the finely stranded tinned copper wire's end, 100% sealed!

This cable is bolted to the mast, with minimal bends, and I use "Jet Lube" copper loaded conductive grease in the interface. (NOT to be confused with "dielectric" grease, which is NON conductive). After cleaning up the squeezed out grease with mineral spirits, dry and apply 5 coats of "Liquid Lectric Tape" vinyl dip. It is now totally conductive and will stay that way (100%) for 40 years!

This huge wire goes straight through the sub floor, (through a through hull packed with silicone caulk, or a wire gland). From inside, under the cockpit, it goes through the next floor down too.

Now you are to the inside of the hull bottom. I have my 2 sq ft (min) copper plate on the side of the mini keel, and it has a curved copper piece that connects through the hull bottom with a 5/8" silicon bronze carriage bolt. On the inside "wire to bolt connection", do as on the mast connection. Same on the outside bolt pass through, except seal the hull's hole, and bed the plate, in 5200.

With grounding plates of the same sq inches, the longer narrower one is best, as linear inches of exposed EDGE is more important than size alone. It dissipates the charge better. This shape I used was a good compromise over a 1" X 288" strap down the hull! Sometimes practicality wins out over theory.

This alone is the most important part, and if you go no further, do this!!! It allows the hit to pas through the hull to "ground" along YOUR route, rather than the lightning's! Dangling a chain in the water, and such as that, is just wishful thinking!

AVOID Dyna Plates. They are not meant for dissipating lightning, and it's just possible that they'd explode. Even as a radio ground... unless you remove it at EACH haul out, and soak it in acid, the pores fill with growth. SO, it is no more surface area than it appears.

For the next level:

After this level of protection, I ran a #6 wire from ALL of the interior chainplate bolts, (except the synthetic runners'), to the copper junction plate over the main pass through bolt. This helps prevent side flashes within the boat. ABYC recommends connecting in the engine & stove too, for the same reason, but I didn't. Due to previous galvanic "issues", I isolated the grounding plate from the boat's AC AND DC systems. This solved the problems. This "isolation", btw, requires that you rubber mount your VHF antenna, as the bracket is DC -. This is very easy to do.

My SSB radio ground is connected with diodes that pass RF energy, but not DC current, but that's a different subject.

MY mast head lightning rod has the "thousand spikes" in a spiral around it, to "THEORETICALLY" bleed off ions and actually lessen the odds of a strike. Hmmm? It is solid science, used on cell phone towers all over the world, but on boats, Who knows? Since it doesn't "take the place" of the lightning rod, it IS one, and there has NEVER been evidence of it making things worse, I gave it a try. May be coincidence, but a boat RIGHT next to me has been hit, rather than me, on THREE occasions. The water or ground within 150' of us, has been hit on 5 or 6 more! Being hundreds of miles out at sea, was not as scary to us as the Chesapeake or ICW, in summer, due to the powerful thunder storms!

I can't really endorse the "fuzzy thing" that I used, may just be BS, but at least ground your mast! Remember, just like gravity: "its the law"!

"IF it hits your mast, it WILL then go to ground"...

M.
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Old 10-08-2012, 09:30   #38
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Re: Lightning Strike Damage Details Needed

Often times I find the discussions on CF enlightening (no pun intended). I consider myself an authority on a few things boat related and not very knowledgeable on many topics...lightning being one of them. That being said I have the good sense to read, sift, follow suggested readings and draw my own conclusions based on fact and other peoples experience. What I am describing is called common sense. And...I extend courtesy where it is due.
One of the problems with the Internet is it allows well intentioned people to use it as a source to spout off information they have based on personal speculation and no scientific facts. It tends to raise the hair on the back of my neck until I realize most members are probably like me and realize the capacity of the source is limited and to take it with a grain of salt. I say most members. The newer members have not yet had a belly full of of the rhetoric to draw this conclusion. But stick around, you will.
You'll find these same people tend to be an authority on...well...just too many subjects. I know I'm not the sharpest pencil in the cup but even if I was, to be an authority on all the topics they claim to know so much about, to the extent they know it, I would have to be 100 years old.
What I have gathered from the lightning thread is that I need to look further into protecting my investment and safety.
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Old 10-08-2012, 09:44   #39
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Re: Lightning Strike Damage Details Needed

What about all the planes that fly through lightning regularly,without losing their electronics?They use those fuzzy carbon dissipator brushes attached to trailing edge of wings for protection.
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Old 10-08-2012, 09:46   #40
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Re: Lightning Strike Damage Details Needed

colemj--i am not TELLING anyone to do a s i do--i am stating the OBVIOUS. EVERY SINGLE BOAT I KNOW OF PERSONALLY--AND YES I DO KNOW MANY boats PERSONALLY ---with alleged dissipators, have ATTRACTED lightning to them to the point of near total damage per insurance companies,,, one more than one time in 4 years. you do the math.

airplanes also go well to weather......
do airplanes fly in a salty oceanic environment????
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Old 10-08-2012, 09:54   #41
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Re: Lightning Strike Damage Details Needed

"What about all the planes" TOTALLY IRRELEVANT.

The aircraft are NOT GROUNDED and the metal skin functions very nicely as a Faraday Cage. Despite this, they sometimes do take lightning damage.

But the big difference is that they are NOT GROUNDED so there is no voltage flowing through them.

Check out the Discover Channel segment on how power companies send electrical lineman in helicopters to work on high voltage transmission lines--while they are live and carrying 6-digit voltages. Same thing. As long as they don't touch a ground, the voltage doesn't bother them.
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Old 10-08-2012, 10:02   #42
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Re: Lightning Strike Damage Details Needed

Mark makes a lot of sense to me. I would also think that surge suppressors would help lesson the chance of electronics getting fried. You can get surge suppressors for the 12V lines as well as coax and other cables. Does anyone use these? What about hooking up surge suppressors to all the switches in the electrical panel? My (limited) understanding is that these work by diverting a high voltage current to ground. If you put a bunch of these on all your devices at the panel, then you could run all the grounding wires to a large copper wire going to ground as in Mark's setup.
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Old 10-08-2012, 12:28   #43
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Re: Lightning Strike Damage Details Needed

Lightning is the #1 killer of all natural disasters on the planet. It is the fact that it is SO common, and kills one at the time, that has it off of the national news. This is as true on boats.
???????????????????????? M Johnson in the post above

Whoa! lighting kills more people than Floods? more than Earthquakes?more than Hurricanes?more than Volcanic eruptions? This truth is suppressed? You have come to this conclusion after reading hundreds of books?
Mr Woodward above post, states:"this make a lots of sense to me".

Haven't anybody here heard and done research on GIANT KRACKNEN!!!!
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Old 10-08-2012, 12:43   #44
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Re: Lightning Strike Damage Details Needed

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Originally Posted by hellosailor View Post
"What about all the planes" TOTALLY IRRELEVANT.

The aircraft are NOT GROUNDED and the metal skin functions very nicely as a Faraday Cage. Despite this, they sometimes do take lightning damage.

But the big difference is that they are NOT GROUNDED so there is no voltage flowing through them.

Check out the Discover Channel segment on how power companies send electrical lineman in helicopters to work on high voltage transmission lines--while they are live and carrying 6-digit voltages. Same thing. As long as they don't touch a ground, the voltage doesn't bother them.
Planes do have issues with lightening. Here's an example from a military report:
Quote:
In another case, lightning attached to the nose pitot tube, inducing transients that damaged all 28
volt DC systems. The pilot, disoriented, broke out of a cloud bank at 2000 feet above the
ground, at 600 knots and a 45 degree dive. Nearly all cockpit instruments were dysfunctional -
compass, gyrohorizon, and so forth. A secondary effect occurred but was not uncovered for
several months. The lightning current path that carried the direct effects lightning current did
what it was supposed to do, but the path was not inspected on landing. Over 800 man-hours
were expended to correct electrical (28 volt DC) problems..
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Old 10-08-2012, 12:49   #45
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Quote:
Originally Posted by highseas
What about all the planes that fly through lightning regularly,without losing their electronics?They use those fuzzy carbon dissipator brushes attached to trailing edge of wings for protection.
They are also an almost perfect "floating ground" which makes the lightening pass over the surface since ther is no ground...

...it isn't an apples to oranges comparison in terms of lightening strike minimization strategy
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