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Larry Larry is offline
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First recorded activity by BoatBanter: Jul 2006
Posts: 5,275
Default Ping Larry: Sintered Bronze

Peter Hendra wrote in
:

I'll add the ground from my stays. By the way, I neglected to tell
that I have a painted box section wooden mast, deck stepped. Forestay,
backstays and capshrouds are electrically connected due to their
attachment at the head of the mast. There is an aluminium sailtrack
which has no connection. Should this be a factor for consideration?


I'd feel better if you'd add a smooth metal cap at the top of the mast to
bleed off static buildup before it causes a strike.

We've learned a lot since the "lightning rod" days, one of the worst
things ever done to protect buildings from lightning. Remember those
sharp-pointed lightning rods that sprayed electrons into the air to
ionize it and GIVE the clouds a path to ground....right at the top of the
flammable barn roof? This was NOT the way to protect buildings!

Today, lightning systems use a grounded, smooth copper flashing that
distributes the electrons along a smooth, long surface to release them
over as wide an area as possible. A pointy grounded thingy ATTRACTS
lightning because there is a concentrated stream of electrons spraying
off the point, ionizing the air above the point...exactly what the cloud
is looking for.

If there's some kind of metal ring at the top of the mast that's grounded
by the various shrouds and stays, that's great. A metal cap that can
take a pretty good strike, might also keep a hit from boiling the sap in
the mast, creating a steam explosion and putting you out of the sailing
business. This alone makes a mast top bypass cap a good thing.

Larry
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