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Default More rebuild and refit photos, grounding the mast?

Additional photos of the rebuild and refit project are now at:

http://www.pbase.com/gould/extreme_makeover

Things are beginning to go back together rapidly. Bow thruster
scheduled to go in next week.
With any luck will be launching in two weekends.

There will be a new aluminum mast and boom installed. I suppose the
yard has this all figured out, but just in case,........

1) The painted aluminum mast will be stepped into a bronze fitting.
With dissimilar metals in contact there is a potential for
electrolysis. Being a stinkpotter and therefore relatively
inexperienced with masts, what precautions, if any, should one take?

2) The old wooden mast wasn't much of a lightning hazard, but the new
mast would serve as an excellent conductor in the event of a lightning
strike. Ideas for grounding? Is it important to ground it?

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RCE
 
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Default More rebuild and refit photos, grounding the mast?


wrote in message
ups.com...
Additional photos of the rebuild and refit project are now at:

http://www.pbase.com/gould/extreme_makeover


2) The old wooden mast wasn't much of a lightning hazard, but the new
mast would serve as an excellent conductor in the event of a lightning
strike. Ideas for grounding? Is it important to ground it?



This is a good question and I've heard a couple of theories. The first is
that a metal mast should be bonded to the boat's bonding plate to discharge
a lightning hit. The problem, according to some people, is that a direct
hit could carry so much current that it literally can blow the bonding plate
apart, resulting in a pretty big hole in the hull.

The alternative is to not bond the mast. In these cases, mucho electronics
that may be mounted on it may be blow, and I've witnessed this on a couple
of sailboats that were hit.

My guess .... and it's only a guess ... is that the metal mast should not be
bonded so well that it can carry large amounts of current. A small diameter
wire that keeps the mast at ground, but would melt quickly in a direct
lightning hit would be my choice.
Again ... just my guess and opinion.

BTW - we are down at the marina right now and I just eyeballed the work they
did on the GB aluminum mast. It was corroded and chauky white last time I
saw it last year. They refinished and painted it with some new type of
marine paint and I swear it looks like highly waxed fiberglass. I have to
find out what the paint is, but it looks fantastic.



RCE


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Default More rebuild and refit photos, grounding the mast?


RCE wrote:


BTW - we are down at the marina right now and I just eyeballed the work they
did on the GB aluminum mast. It was corroded and chauky white last time I
saw it last year. They refinished and painted it with some new type of
marine paint and I swear it looks like highly waxed fiberglass. I have to
find out what the paint is, but it looks fantastic.



RCE


If that "new paint" is ALEXSEAL, that's what we used to paint our
entire hull.

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RCE
 
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Default More rebuild and refit photos, grounding the mast?


wrote in message
oups.com...

RCE wrote:


BTW - we are down at the marina right now and I just eyeballed the work
they
did on the GB aluminum mast. It was corroded and chauky white last time
I
saw it last year. They refinished and painted it with some new type of
marine paint and I swear it looks like highly waxed fiberglass. I have
to
find out what the paint is, but it looks fantastic.



RCE



I checked up at the office. That's what they used. They've done a couple of
boat hulls with it last winter and say it's the best paint they have ever
used. No wonder your boat is coming out so nice.

RCE
If that "new paint" is ALEXSEAL, that's what we used to paint our
entire hull.



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Danlw
 
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Default More rebuild and refit photos, grounding the mast?


wrote in message
ups.com...
Additional photos of the rebuild and refit project are now at:

http://www.pbase.com/gould/extreme_makeover

Things are beginning to go back together rapidly. Bow thruster
scheduled to go in next week.
With any luck will be launching in two weekends.

There will be a new aluminum mast and boom installed. I suppose the
yard has this all figured out, but just in case,........

1) The painted aluminum mast will be stepped into a bronze fitting.
With dissimilar metals in contact there is a potential for
electrolysis. Being a stinkpotter and therefore relatively
inexperienced with masts, what precautions, if any, should one take?

2) The old wooden mast wasn't much of a lightning hazard, but the new
mast would serve as an excellent conductor in the event of a lightning
strike. Ideas for grounding? Is it important to ground it?\



Thanks for the update and photos! Hope to see the boat in person on the
water sometimw! Dan





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JimH
 
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Default More rebuild and refit photos, grounding the mast?


wrote in message
ups.com...
Additional photos of the rebuild and refit project are now at:

http://www.pbase.com/gould/extreme_makeover

Things are beginning to go back together rapidly. Bow thruster
scheduled to go in next week.
With any luck will be launching in two weekends.

There will be a new aluminum mast and boom installed. I suppose the
yard has this all figured out, but just in case,........

1) The painted aluminum mast will be stepped into a bronze fitting.
With dissimilar metals in contact there is a potential for
electrolysis. Being a stinkpotter and therefore relatively
inexperienced with masts, what precautions, if any, should one take?

2) The old wooden mast wasn't much of a lightning hazard, but the new
mast would serve as an excellent conductor in the event of a lightning
strike. Ideas for grounding? Is it important to ground it?


Looks like she will be a beauty Chuck!


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Reginald P. Smithers III
 
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Default More rebuild and refit photos, grounding the mast?

Harry Krause wrote:

wrote in message
ups.com...
Additional photos of the rebuild and refit project are now at:

http://www.pbase.com/gould/extreme_makeover

Things are beginning to go back together rapidly. Bow thruster
scheduled to go in next week.
With any luck will be launching in two weekends.

There will be a new aluminum mast and boom installed. I suppose the
yard has this all figured out, but just in case,........

1) The painted aluminum mast will be stepped into a bronze fitting.
With dissimilar metals in contact there is a potential for
electrolysis. Being a stinkpotter and therefore relatively
inexperienced with masts, what precautions, if any, should one take?

2) The old wooden mast wasn't much of a lightning hazard, but the new
mast would serve as an excellent conductor in the event of a lightning
strike. Ideas for grounding? Is it important to ground it?\



Thanks for the update and photos! Hope to see the boat in person on
the water sometimw! Dan



Nylon bushings and washers.


Harry,
This seems like a great and easy solution, but I would question the
strength and longevity of the bushing and washers, both from stress
fatigue and UV degradation. I know they have made advances in nylon and
plastic but I still would be leery of this w/o follow up by some
experts. I don't know the answer, but if this was a viable long term
solution, I would think it would be standard on new sailboats.

Chuck,
I can be guilty of over engineering a solution, so I only have to do a
project once, but I would contact sailboat and trawler mfger's or even
your boatyard (you must have a lead or two) and ask for their
recommendations. My ignorant uneducated solution would be to separate
the two problems and solve each separately. I would see if quality
caulk to keep water and oxygen away from the dissimilar metals would be
a viable long term solution. Then use a lighting dissipators at the top
of the mast to reduce the risk of lightning.

http://www.fourwinds-ii.com/lightning/lightning.htm


I have always liked the look of a classic trawler and this will turn
heads on the water.
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Reginald P. Smithers III
 
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Default More rebuild and refit photos, grounding the mast?

Reginald P. Smithers III wrote:
Harry Krause wrote:

wrote in message
ups.com...
Additional photos of the rebuild and refit project are now at:

http://www.pbase.com/gould/extreme_makeover

Things are beginning to go back together rapidly. Bow thruster
scheduled to go in next week.
With any luck will be launching in two weekends.

There will be a new aluminum mast and boom installed. I suppose the
yard has this all figured out, but just in case,........

1) The painted aluminum mast will be stepped into a bronze fitting.
With dissimilar metals in contact there is a potential for
electrolysis. Being a stinkpotter and therefore relatively
inexperienced with masts, what precautions, if any, should one take?

2) The old wooden mast wasn't much of a lightning hazard, but the new
mast would serve as an excellent conductor in the event of a lightning
strike. Ideas for grounding? Is it important to ground it?\


Thanks for the update and photos! Hope to see the boat in person on
the water sometimw! Dan



Nylon bushings and washers.


Harry,
This seems like a great and easy solution, but I would question the
strength and longevity of the bushing and washers, both from stress
fatigue and UV degradation. I know they have made advances in nylon and
plastic but I still would be leery of this w/o follow up by some
experts. I don't know the answer, but if this was a viable long term
solution, I would think it would be standard on new sailboats.

Chuck,
I can be guilty of over engineering a solution, so I only have to do a
project once, but I would contact sailboat and trawler mfger's or even
your boatyard (you must have a lead or two) and ask for their
recommendations. My ignorant uneducated solution would be to separate
the two problems and solve each separately. I would see if quality
caulk to keep water and oxygen away from the dissimilar metals would be
a viable long term solution. Then use a lighting dissipators at the top
of the mast to reduce the risk of lightning.

http://www.fourwinds-ii.com/lightning/lightning.htm


I have always liked the look of a classic trawler and this will turn
heads on the water.



I hope you know I mean YOUR BOAT will turn heads, not the lighting
dissipator.
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DSK
 
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Default More rebuild and refit photos, grounding the mast?

wrote:
Additional photos of the rebuild and refit project are now at:

http://www.pbase.com/gould/extreme_makeover

Things are beginning to go back together rapidly. Bow thruster
scheduled to go in next week.
With any luck will be launching in two weekends.


WOW awesome job Chuck. I am deliberately NOT going to show
my wife your pictures, hope you understand


There will be a new aluminum mast and boom installed. I suppose the
yard has this all figured out, but just in case,........

1) The painted aluminum mast will be stepped into a bronze fitting.
With dissimilar metals in contact there is a potential for
electrolysis. Being a stinkpotter and therefore relatively
inexperienced with masts, what precautions, if any, should one take?


A sheet of rubber gasket should be just fine, shape to fit
between mast butt & step. Another option is to paint the
mast butt with that liquid plastic tool handle coating (one
brand is named "Dip-It" commonly sold in hardware stores).


2) The old wooden mast wasn't much of a lightning hazard, but the new
mast would serve as an excellent conductor in the event of a lightning
strike. Ideas for grounding? Is it important to ground it?


Personally, I wouldn't worry about it. It may be more
effective to put a static dissipator brush on the tip and
leave it ungrounded. A lightning ground would be difficult
to install since it not only has to be thich cable, but also
relatively straight and on your boat it would have to come
down right thru the aft cabin. A minimum lighting ground
(think in terms of millions of volts) would be a 4" wide
braided cable with no turn of less than 8" radius.


RCE wrote:

This is a good question and I've heard a couple of theories. The first is
that a metal mast should be bonded to the boat's bonding plate to discharge
a lightning hit. The problem, according to some people, is that a direct
hit could carry so much current that it literally can blow the bonding plate
apart, resulting in a pretty big hole in the hull.


That's not a good idea IMHO. The bonding system will not
handle anywhere near the current of a lightning strike and
will only result in scattering the damage all thru the boat.
It will also result in more stray charges in the bonding
system which may cause other long-term problems even if
lightning never strikes.


The alternative is to not bond the mast. In these cases, mucho electronics
that may be mounted on it may be blow, and I've witnessed this on a couple
of sailboats that were hit.

My guess .... and it's only a guess ... is that the metal mast should not be
bonded so well that it can carry large amounts of current. A small diameter
wire that keeps the mast at ground, but would melt quickly in a direct
lightning hit would be my choice.
Again ... just my guess and opinion.


Sort of like a fuse? Not to be argumentative but the problem
with this idea is that the energy *will* go somewhere. It's
like you've invited this billion volt beast on your boat and
then tried to shut a flimsy hatch in his face. A mast should
either be ungrounded (and with a short mast like a
trawler's, this is not that big a risk) or well enough
grounded to take a hit. Either way the electronics connected
to it will be fried, that's a given. But a well grounded
mast will not damage other parts of the boat.

Lightning can do all kinds of funny stuff, from burning
holes thru the hull to melting ropes to setting wood
paneling on fire. I've know it to burn up alternators via
the boat's ground system. Some friends of ours just had
their sailboat hit by lightning and it fried all their
electronics and put what looked like cigarette burn holes in
their sails.

Fair Skies
Doug King

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Wayne.B
 
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Default More rebuild and refit photos, grounding the mast?

On 11 Jun 2006 10:13:19 -0700, "
wrote:

2) The old wooden mast wasn't much of a lightning hazard, but the new
mast would serve as an excellent conductor in the event of a lightning
strike. Ideas for grounding? Is it important to ground it?


The mast should definitely be grounded, preferably in several
different ways. By doing that, the mast behaves much like the
lightning rods on a building, bleeding off accumulated charge before
it builds into a full strike. That said, sailboat masts still get hit
very frequently, and damage to electronic equipment is not uncommon.

At dock or anchored, very large sailboats frequently hang zinc "fish"
from the rigging wires into the water to provide additional
protection. I do that with our GB49 here in south Florida where
thunderstorms are an almost daily event during the summer months. Not
sure if it really helps, but it feels like I'm doing something
proactive.

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