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Cyrus Safdari · 27-03-2018, 13:10

FYI folks Faraday cages only work if they're grounded. Your oven probably isn't.

ArmyDaveNY · 27-03-2018, 13:14

Quote:

Originally Posted by Olddan1943

Ask the ding bat congress woman from Calif. She will get it for you.

True. Here are just a few actual studies:

The U.S. government has spent $175,587 “to determine if cocaine makes Japanese quail engage in sexually risky behavior
$856,000 to film mountain lions running on treadmills
$331,000 to study whether "Hangry" spouses are more likely to stab voodoo dolls.
How do soap operas portray coma patients.

Sadly the list goes on. And on. And on.

RPZ · 27-03-2018, 13:16

Quote:

Originally Posted by Cyrus Safdari

OK imagine the total electrical output of Hoover Dam, trying to go through a length copper cable...

Not an expert, but I believe lightning generally seeks the most direct and conductive path to ground. If it strikes an aluminum mast would that not be a path it would take directly into water as opposed to having to jump from the mast base through thick fiberglass to reach water?

Another thought... What if the mast, instead of being stepped on the cabin floor/keel was stepped on a non-conductive pillar at cabin roof or deck level?

Which leads to yet another question; what are the percentages of keel stepped mast strikes as opposed to cabin roof/ deck stepped mast boats?

Cadence · 27-03-2018, 13:17

Quote:

Originally Posted by Cyrus Safdari

FYI folks Faraday cages only work if they're grounded. Your oven probably isn't.

Since the whole thing is getting somewhat bosh. Lets tie the rigging to the stove and then to a grounding plate.

GTom · 27-03-2018, 13:29

Quote:

Originally Posted by Cyrus Safdari

FYI folks Faraday cages only work if they're grounded. Your oven probably isn't.

I am by no means expert on lightnings, just found this.

Quote:

Remember that a Faraday cage without any wire penetrations does not need to be grounded, and any attempt to ground such an uncomplicated faraday cage is simply asking for problems.

BTW, Aircraft hulls also act like Faraday cages and they're definitely not grounded

OTOH, people smarter than me say it's better grounded. Reasoning: charge buildup on the cage - this doesn't destroy the equipment inside, but if you touch it you can get a hit. However, I've never heard of anyone being hit half an hour after a lightning strike when he/she wanted to open the oven...

Cyrus Safdari · 27-03-2018, 13:45

Quote:

Originally Posted by Cadence

Hoover Dams output and lightning is apples and oranges.

It was a rhetorical point: that's a lot of energy to expect a little cable dangling in the water to carry away from your boat.

Cyrus Safdari · 27-03-2018, 13:48

Quote:

Originally Posted by GTom

BTW, Aircraft hulls also act like Faraday cages and they're definitely not grounded

Aircraft along with birds sitting on electrical wires, are not part of a complete circuit.

OK you don't *need* to ground a faraday cage 9as long as there's nothing conductive penetrating the cage from the outside (have you seen the inside of your oven and the wires/mechanics in there?) but yuo're far better off doing so

Cadence · 27-03-2018, 14:09

Quote:

Originally Posted by Cyrus Safdari

It was a rhetorical point: that's a lot of energy to expect a little cable dangling in the water to carry away from your boat.

I agree! I'm in the camp that bonding may be counter productive. But who the hell knows. What is it St. Elmo's fire? Is there a reason for the connection to the patron saint of sailors?

GTom · 27-03-2018, 14:10

Quote:

Originally Posted by Cyrus Safdari

Aircraft along with birds sitting on electrical wires, are not part of a complete circuit.

Neither is your stove if it's not grounded. Even if it gets in the path, it passes on the lightning, just like this guy:

https://youtu.be/i-LCORFB860?t=2m42s

Quote:

OK you don't *need* to ground a faraday cage 9as long as there's nothing conductive penetrating the cage from the outside (have you seen the inside of your oven and the wires/mechanics in there?) but yuo're far better off doing so

You are right, I will rather use an old school metal toolbox or something similar. The stove is reserved for the dinner anyway

RPZ · 27-03-2018, 14:32

By the same token I'm somewhat amazed that lightning striking a mast top doesn't melt and collapse an aluminum mast - and all the rigging. Evidently that doesn't happen, or at least I have not heard or read of it.

GTom · 27-03-2018, 14:59

An aluminum mast has a vast cross section, therefore very little resistence. Rigging is less conductive, still plenty of wire strength there for a short pulse.

chris95040 · 27-03-2018, 16:45

Quote:

Originally Posted by Cyrus Safdari

FYI folks Faraday cages only work if they're grounded. Your oven probably isn't.

Car chassis aren't grounded, and they are often cited as an example of a faraday cage providing lightning protection.

RPZ · 27-03-2018, 16:58

The chassis is not grounded, but all electrical systems are grounded to the chassis.

Same with an aircraft. A German friend of mine was killed, along with his first officer and 19 passengers after the commercial Fairchild twin prop he was flying was struck by lightning in 1988. The lightning strike killed instruments and electrical systems.

Saleen411 · 27-03-2018, 17:48

Quote:

Originally Posted by RPZ

The chassis is not grounded, but all electrical systems are grounded to the chassis.

Same with an aircraft. A German friend of mine was killed, along with his first officer and 19 passengers after the commercial Fairchild twin prop he was flying was struck by lightning in 1988. The lightning strike killed instruments and electrical systems.

Tragic accident....sorry for your loss.

I'm certainly no expert on lightning strikes, but I have been struck more than a few times....no electrical system damage or instrument failures....just some pin holes. I know pilots who have had considerable damage after being struck.

I've also experienced St Elmo's fire and static discharges (BOOM) with no accompanying lightning strike. Some of the actual strikes sounded just like thumps, and a few sounded like a small fire cracker. One sounded like a cherry bomb.

Here's a video showing a few strikes....