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SVArgo 07-13-2015 05:12 PM

Bonding and Grounding of Underwater Metals
 
Can anyone advise how all their below waterline seacocks, through-hulls, and other metal elements are bonded? In theory they should all be bonded with minimum 8AWG cable and all that should be tied to the DC ground bus or negative engine terminal. Not sure mine is quite like that and am trying to figure out what the factory baseline configuration is.

Thanks,
Ryan

Lantau 07-13-2015 07:36 PM

Re: Bonding and Grounding of Underwater Metals
 
Hmm. Can of worms. I think think this is one of those questions that you'll get different opinions on. I think most of your fittings should NOT be bonded together (they should be kept isolated). How's that for disagreement already? It depends on what you want to do it for. Is it for protection from a lightening strike or to prevent corrosion from stray current in the boat or from stray current in a marina? These require different approaches, but I think none results in bonding everything together. For example, if it's lightening you're worried about (to protect you if not your electronics, which can probably only be protected by the gods), you'd want to bond things near the mast. If boat current is a problem, fix the problem. If marina current is the problem, bonding everything could just make it worse. Unless a previous owner has changed something, your boat may be bonded appropriately right now. Don Casey's boat fixing book has a section on this sort of thing. But, again, I think you are going to get different perspectives on this. (Like my recent question on lifelines: some say wire, some say rope, and never the twain shall meet.) As for my 37, which I'm confident is still 'bonded' as it was from the factory, almost all of the underwater fittings are NOT bonded together.

CalebD 07-13-2015 08:17 PM

Re: Bonding and Grounding of Underwater Metals
 
If lightning is your concern then there is no scientific research that proves that a bonded boat is better protected than a non bonded boat. It is difficult to set up controlled experiments with 10,000,000 volts of electricity.
Anecdotally, non-bonded boats do not get hit as often as bonded boats but bonded boats may be able to survive a lightning strike with minimal damage.

wsmurdoch 07-13-2015 08:58 PM

Re: Bonding and Grounding of Underwater Metals
 
A description of the PSC 34 ground systems is in the PSC 34 Owner's Manual. I assume a description of the ground systems is also in the PSC 37 Owner's Manual.

If you don't have a copy, you can Google the Pacific Seacraft 34 Owner's Manual; perhaps the 37 systems are similar/identical.

Bill Murdoch
1988 PSC 34
Irish Eyes

SVArgo 07-13-2015 09:08 PM

Re: Bonding and Grounding of Underwater Metals
 
I guess my specific question is: How is your Pacific Seacraft bonded?

The professional marine community very clearly articulates the need, and requirement for, bonding of underwater hull elements. It's a safety issue; everything on the boat should be at the same potential. This is an ABYC (American Boat and Yacht Council) requirement for yachts and motor boats, a US CFR (United States Code of Federal Regulations) requirement for passenger and commercial vessels, and a design and operational requirement for vessels of the U.S. Coast Guard and U.S. Navy.

I'm not terribly concerned about the lightning protection, save for the fact to increase the bonding wire size from 8AWG to 6AWG where bonding conductors are installed as a secondary or parallel path for the main lightning conductor.

Ryan

Quote:

Originally Posted by Lantau (Post 2906849)
Hmm. Can of worms. I think think this is one of those questions that you'll get different opinions on. I think most of your fittings should NOT be bonded together (they should be kept isolated). How's that for disagreement already? It depends on what you want to do it for. Is it for protection from a lightening strike or to prevent corrosion from stray current in the boat or from stray current in a marina? These require different approaches, but I think none results in bonding everything together. For example, if it's lightening you're worried about (to protect you if not your electronics, which can probably only be protected by the gods), you'd want to bond things near the mast. If boat current is a problem, fix the problem. If marina current is the problem, bonding everything could just make it worse. Unless a previous owner has changed something, your boat may be bonded appropriately right now. Don Casey's boat fixing book has a section on this sort of thing. But, again, I think you are going to get different perspectives on this. (Like my recent question on lifelines: some say wire, some say rope, and never the twain shall meet.) As for my 37, which I'm confident is still 'bonded' as it was from the factory, almost all of the underwater fittings are NOT bonded together.


Lantau 07-13-2015 09:43 PM

Re: Bonding and Grounding of Underwater Metals
 
[QUOTE=SVArgo;2907073]... This is an ABYC (American Boat and Yacht Council) requirement for yachts and motor boats, a US CFR (United States Code of Federal Regulations) requirement for passenger and commercial vessels, and a design and operational requirement for vessels of the U.S. Coast Guard and U.S. Navy...


I think you know best, but when I checked the requirements that folks referred to on this list for lifeline requirements, I found that many people were wrong or were referring to old requirements or interpreting them wrongly (at least by my reading, which with respect to lifelines says that rope is still approved). As I say, I think you probably know best, but it's worth checking the latest requirements again if you haven't done it recently. If what you say was true in 2004, then Pacific Seacraft blatantly violated the ABYC requirements when building my boat. I really doubt they'd do that -- but I could be wrong. (By the way, if commercial boats are your reference, I think you may find that any Pacific Seacraft also violates the rules on lifelines there, too.)

As I said, I think this is one of those cans of worms that will be hard to get clarity on in this forum.

I'm off to the boat so I can sail it over to a rigger to get his view on replacing my lifelines. I already know that whatever he says, many other riggers will disagree with him. That's boats...

SVArgo 07-13-2015 10:20 PM

Re: Bonding and Grounding of Underwater Metals
 
Landau,

I just looked through my owner's manual, and it doesn't refer to ABYC at all, so the systems may not be in compliance. It only states the hull plans were reviewed by ABS (American Bureau of Shipping), though it doesn't really give a clear and holistic picture of the design and construction technical and regulatory baseline. Even though ABYC is a voluntary regulatory regime, almost all major builders do indeed build to it, so I'll be surprised if PacSea is an exception.

I've spent the past two weeks on ABYC Standards, Electrical, and Corrosion certification training, so am pretty clear on what's required today. And while the standards do change over time, I'm fairly confident that the bonding and grounding portions have been around since at least my year of construction (1995), but will ask the instructor tomorrow.

Pacsea's aren't designed under the CFR's and can really only operate commercially as a OUPV (Offshore Uninspected Passenger Vessel), aka 6-pack. Anything more than that and the full force of the CFR is invoked for an inspected (COI) vessel.

So, I guess I need to modify my original question:

Does Pacific Seacraft build to ABYC, and if so, have they always? And what is the below the waterline bonding as installed on boats from the factory?

For your lifelines: double braid dyneema or equivalent have worked fine for me for the past 5 years, need minor lashing replacement, but there is no visible damage to the core and they still meet the pull/static test.

Ryan

[quote=Lantau;2907193]
Quote:

Originally Posted by SVArgo (Post 2907073)
... This is an ABYC (American Boat and Yacht Council) requirement for yachts and motor boats, a US CFR (United States Code of Federal Regulations) requirement for passenger and commercial vessels, and a design and operational requirement for vessels of the U.S. Coast Guard and U.S. Navy...


I think you know best, but when I checked the requirements that folks referred to on this list for lifeline requirements, I found that many people were wrong or were referring to old requirements or interpreting them wrongly (at least by my reading, which with respect to lifelines says that rope is still approved). As I say, I think you probably know best, but it's worth checking the latest requirements again if you haven't done it recently. If what you say was true in 2004, then Pacific Seacraft blatantly violated the ABYC requirements when building my boat. I really doubt they'd do that -- but I could be wrong. (By the way, if commercial boats are your reference, I think you may find that any Pacific Seacraft also violates the rules on lifelines there, too.)

As I said, I think this is one of those cans of worms that will be hard to get clarity on in this forum.

I'm off to the boat so I can sail it over to a rigger to get his view on replacing my lifelines. I already know that whatever he says, many other riggers will disagree with him. That's boats...


DMD 07-13-2015 10:55 PM

Re: Bonding and Grounding of Underwater Metals
 
Ryan,
Without wading into the discussion about what is "right", I will offer at least one data point: Our 1983 Pacific Seacraft 37 has no bonding and I believe this is original. All seacocks are isolated, .i.e. no bonding wires. We do have lightning ground cables that run from the chainplates and mast to a dynaplate. The Keel is not bonded electrically to anything.
Our bronze seacocks are all original (Groco model SV with rubber plug spool) and in good working condition with no dezincification visible on valves or thru-hulls.

Dave
Crealock 37 #151
"Eowyn"

wsmurdoch 07-13-2015 11:03 PM

Re: Bonding and Grounding of Underwater Metals
 
Quote:

Originally Posted by SVArgo (Post 2907073)
How is your Pacific Seacraft bonded?

When I bought Irish Eyes in 2004, there was a black wire that ran from each seacock to the Dynaplate below the mast. An additional black wire ran from the engine to the Dynaplate which thus connected the battery negative to the Dynaplate. The mast base was connected to the Dynaplate with another black wire as were the shrouds, forestay, and backstay. The fuel tank and windlass motor are similarly connected. I installed a tear drop zinc to the system to slow the loss of the more expensive propeller nut zinc. I installed a galvanic isolator and connected the AC ground to the DC negative at that time. I replaced the corroded and damaged Dynaplate with a slightly larger solid copper plate on the advice of the surveyor. I have replaced or re-terminated several of the black wires when they appeared to be badly corroded.

My boat has the SSB ground system, and I know that the Dynaplate is in electrical contact with the lead keel although I do not know how.

The lower rudder gudgeon does not seem to be part of the system.

I'm not sure of the pulpit, pushpit, or stove.

Bill Murdoch
1988 PSC 34
Irish Eyes

Maine Sail 07-14-2015 07:26 AM

Re: Bonding and Grounding of Underwater Metals
 
Quote:

Originally Posted by SVArgo (Post 2907249)

I've spent the past two weeks on ABYC Standards, Electrical, and Corrosion certification training, so am pretty clear on what's required today. And while the standards do change over time, I'm fairly confident that the bonding and grounding portions have been around since at least my year of construction (1995), but will ask the instructor tomorrow.


Can you please show us where in the standards bonding for corrosion or lightning are requirements?

E-2 is a recommendation for how to properly do an an "installed bonding system" not a requirement to install such a system.


"E-2 2.1 PURPOSE

This standard is a guide for the design, installation, and use of cathodic protection systems on boats."


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