Hey folks, doe's anyone happen to know where the lightening ground plate is located? I have a Cal 25-2 but I suspect most Cals are located in the same place. I suspect it's located in the hull under where the head is located. I see a heavy ground wire disappearing into the fiberglass hull there.
Lightening ground plate
- Thread starter Gary_H
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Hi Gary,
The CAL 2-25 has an encapsulated lead keel that is insulated from the water. On my 1979 model a single stand of heavy bare copper wire (assumed to be connected to the mast) exits the hull fiberglass inside the locker under the port side of the V-berth. This was connected to the vanity sink through-hull and all of the through-hulls were connected to each other with a similar sized wire. The vanity trough-hull and ball valve showed a lot of corrosion when I bought the boat three years ago. All of the through-hulls are original and are not traditional seacocks but bronze ball valves mounted on the through-hulls. Relacing the vanity through-hull is on my project list even though all of them function properly and passed both the purchase and insurance surveys. I use the past tense when describing the ground wiring as they are now all disconnected on the recommendation of the surveyor to reduce galvanic corrosion due to different voltage potentials in our marina (too many aluminum power boats). Remember that the mast and DC electrical are also grounded to the Yanmar motor and thus the propeller shaft.
I don't know about your area but lighting is non-issue here on the wet west coast of Canada. Lighting is very rare and occurs about as often as snow (one about every second or third winter). We actually look forward to these strange winter storm events.
The CAL 2-25 has an encapsulated lead keel that is insulated from the water. On my 1979 model a single stand of heavy bare copper wire (assumed to be connected to the mast) exits the hull fiberglass inside the locker under the port side of the V-berth. This was connected to the vanity sink through-hull and all of the through-hulls were connected to each other with a similar sized wire. The vanity trough-hull and ball valve showed a lot of corrosion when I bought the boat three years ago. All of the through-hulls are original and are not traditional seacocks but bronze ball valves mounted on the through-hulls. Relacing the vanity through-hull is on my project list even though all of them function properly and passed both the purchase and insurance surveys. I use the past tense when describing the ground wiring as they are now all disconnected on the recommendation of the surveyor to reduce galvanic corrosion due to different voltage potentials in our marina (too many aluminum power boats). Remember that the mast and DC electrical are also grounded to the Yanmar motor and thus the propeller shaft.
I don't know about your area but lighting is non-issue here on the wet west coast of Canada. Lighting is very rare and occurs about as often as snow (one about every second or third winter). We actually look forward to these strange winter storm events.
Mast Ground
Just discovered that somehow my CAL 2-25 mast is electrically connected to the ocean. It is at the same electrical potenial as the battery negative and the Yanmar frame. I've checked and I do not have a problem with any of the mast wiring (all conductors are floating when disconnected from the power and common connections). The keel as with most newer CALs is encapsulated in the hull. I only thing that would make sense is if there is a hidden wire from the base of the mast to some exposed "ground plate" metal on the bottom of the keel?
Just discovered that somehow my CAL 2-25 mast is electrically connected to the ocean. It is at the same electrical potenial as the battery negative and the Yanmar frame. I've checked and I do not have a problem with any of the mast wiring (all conductors are floating when disconnected from the power and common connections). The keel as with most newer CALs is encapsulated in the hull. I only thing that would make sense is if there is a hidden wire from the base of the mast to some exposed "ground plate" metal on the bottom of the keel?
Sorry I haven't gotten back to this post in a while. My situation is identicle to yours. When I first got the boat all the throughulls where bonded together with a bare copper wire that then dissapeared into the bottom fiberglass. I was reading Don Casey book "Sailboat Electric Simplified " and he advised that throughhulls should not be bonded if they can be otherwise Isolated like by it being connected to a rubber hose. All three through hulls under the Vberth were nasty so I disconnected the ground wires and then cleaned them up. They have stayed clean ever since. I know the mast, stays and shrouds are supposed to be grounded to a lightening ground plate. I suspect that there is one but I don'e recall seeing one on the bottom of the boat when it was on the hard getting painted. . I also haven't seen the a ground anywhere at the bottom of the mast only from the shrouds and chainplates.The DC system is grounded through the engine and thus through the shaft and prop. I don't think the prop and shaft have sufficient area to prperly act as a lightening ground. I 'm still trying to figure it out on My Cal 2-25.
OK this is taken directly from the Cal 25-2 owners manual.
"
So it apears that there never was a lightening ground plate factory installed. everything is grounded through the engine shaft and prop.
"
LIGHTNING GROUND
The spars and standing rigging on all Cal Yachts are grounded,
in compliance with the American Boat and Yacht Council Project
E-4, to attempt to minimize damage resulting from -lightning and
provide a measure of safety for personnel.
Each chainplate, the mast step, and all thru-hulls are attached
by means of a #8 AWG solid copper wire to the engine and/or strut.
In the event -lightning strikes the spar, the system is designed
to carry the charge by the wire to ground"The spars and standing rigging on all Cal Yachts are grounded,
in compliance with the American Boat and Yacht Council Project
E-4, to attempt to minimize damage resulting from -lightning and
provide a measure of safety for personnel.
Each chainplate, the mast step, and all thru-hulls are attached
by means of a #8 AWG solid copper wire to the engine and/or strut.
In the event -lightning strikes the spar, the system is designed
So it apears that there never was a lightening ground plate factory installed. everything is grounded through the engine shaft and prop.
Gary,
Your last post seems to make sense for my '73 2-29 also. I have a copper wire running under the floor pan connected to all the through hulls and the side top shrouds and the for/aft stays. It is also attached to the keel bolts and the shaft strut bolts. I guess the idea was to bond for lightening protection only and not for corrosion protection. I read Don Casey's section on groundign and bonding and I must admit I did not come away with a celar understanding of what to do for corrosion protection. Don's writing is as clear as a bell and I understand everything else in the book except for this.
I don't think the prop shaft and engine are bonded to this system - at least they aren't on my 2-29. The engine is separated from the prop shaft with the 4" rubber coupling and the strut is separated from the shaft with the rubber bearing. My lightning protection seems to be up to Don's specs but I dont seem to have any corrosion protection beyond the shaft zinc. I am thinking about connecting the engine to a permanent through hull zinc - although the idea of drillign another hole in the hull is less than desirable. (I did add 2 transducers, though so far so good). My A-30 is showing signs of her age. She has a lot of rust inside the head - I take it off every season and brush out what rust I can.
Your last post seems to make sense for my '73 2-29 also. I have a copper wire running under the floor pan connected to all the through hulls and the side top shrouds and the for/aft stays. It is also attached to the keel bolts and the shaft strut bolts. I guess the idea was to bond for lightening protection only and not for corrosion protection. I read Don Casey's section on groundign and bonding and I must admit I did not come away with a celar understanding of what to do for corrosion protection. Don's writing is as clear as a bell and I understand everything else in the book except for this.
I don't think the prop shaft and engine are bonded to this system - at least they aren't on my 2-29. The engine is separated from the prop shaft with the 4" rubber coupling and the strut is separated from the shaft with the rubber bearing. My lightning protection seems to be up to Don's specs but I dont seem to have any corrosion protection beyond the shaft zinc. I am thinking about connecting the engine to a permanent through hull zinc - although the idea of drillign another hole in the hull is less than desirable. (I did add 2 transducers, though so far so good). My A-30 is showing signs of her age. She has a lot of rust inside the head - I take it off every season and brush out what rust I can.
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