Bonding Information

http://ir.library.oregonstate.edu/xmlui/bitstream/handle/1957/4829/SR no. 622_ocr.pdf

I just stumbled across the above link which describes a boat bonding system and recommendations. Looks like good information to me but.......

my electrical knowledge makes me some times wonder why there isn't a puddle of electricity on the floor when nothing is plugged in a wall socket.

ktdtx said:

http://ir.library.oregonstate.edu/xmlui/bitstream/handle/1957/4829/SR no. 622_ocr.pdf

I just stumbled across the above link which describes a boat bonding system and recommendations. Looks like good information to me but.......

my electrical knowledge makes me some times wonder why there isn't a puddle of electricity on the floor when nothing is plugged in a wall socket.

Click to expand...

I didn't read in its entirety. General premise seems fine. Article/instructions dated just a bit.

Interesting read.

Much of that paper is based on the premise that you have a single sideband radio. SSBs still exist but sat phones have mostly taken their place. Also coastal trawlers don't need one.


The discussion about running all DC power wiring in shielded cable is silly. Where does one buy shielded 14, 12 and 10 gauge wire. And of course that recommendation is specific to SSB radios even though it is not needed for them.


Any discussion of bonding ought to talk about lightning grounding, but that topic is beyond my ken. But if I were a blue water cruiser I would have some lighting protection capability.


In summary bond all underwater metals with a green preferably #8 wire and bring all connections to a common point, usually the engine block as the article suggests. There is no need for a shaft brush unless you have a drive saver or equivalent.


David

I think you'll find more up to date information in Calder's book.

"Where does one buy shielded 14, 12 and 10 gauge wire."

Any large commercial wire supply .

I use it and it costs little more than cheapo wire in a good quantity.

Cuts down om RFI from pumps and alt. on AM radio

But don't bond a wooden boat

Just to point out, since there are a few of us here crazy enough to own them, that bonding of metal fittings on wooden boats can cause electrolysis damage to the wood and is generally a bad idea.

See for example NVIC 7-95, page 4-11.

FF said:

"Where does one buy shielded 14, 12 and 10 gauge wire."

Any large commercial wire supply .

Click to expand...

Is it tinned?

David

"Is it tinned?

Of course , in the catalog it was listed as Naval gun fire wire, but its been years since I have seen the catalog.

It even has hemp ot jute in the inner portion to keep the wire round.

Wrong, wrong, wrong about wood boats and bonding. Wood boats are the REASON for bonding. No other material that boats are built of require it. A wood boat with metal thru hulls that are not bonded is a semi conductor and "can" suffer from delignification. Bad juju. Bonding is a holdover from wood boat days because insurance companies figured out that the metal in contact with water and wet/damp wood caused the delignification "fuzzy stuff" around the fitting which weakend the wood causing boats to sink. Afterward they required ALL boats to be bonded, needed or not. I am not an advocate of electrical bonding, and in fact have ranted at length about it on FG boats. But if you have a wood boat it really needs a good and well maintained complete bonding system.

No factory bonding system installed on early Marshall Californians.

At last haul out, I was concerned about my 39 year old through hull fittings, so we pulled, cleaned, inspected and reinstalled them all. No corrosion. No plate zinc, just a zinc on each rudder, two ball zincs on each shaft, and a pencil zinc in each cooler.

I'm more concerned about lightning strikes since I have a 13' aluminum mast.

kulas44 said:

But if you have a wood boat it really needs a good and well maintained complete bonding system.

Click to expand...

Did you read the USCG circular I linked to?

Edelweiss said:

No factory bonding system installed on early Marshall Californians.

At last haul out, I was concerned about my 39 year old through hull fittings, so we pulled, cleaned, inspected and reinstalled them all. No corrosion. No plate zinc, just a zinc on each rudder, two ball zincs on each shaft, and a pencil zinc in each cooler.

I'm more concerned about lightning strikes since I have a 13' aluminum mast.

Click to expand...

Larry, are you still without any bonding on your fittings or did you add some at a later date?

I'm not saying all wood boats are effected, just that back in the day it was enough of a problem that ins. co.s started requiring boats to be bonded. I have not looked at the link, but will.

No, that was my question too. But the shop electrician said if there wasn't any problem with electrolysis on the fittings after all these years, there was no reason to add it. We added a heavy ground strap to earth ground for the mast though.

He did mention that a lot of the Asian built trawlers aren't so luck. I'm assuming he meant there were differences in the quality of the bronze fittings or the boats electrical, but I didn't push it with him.

kulas44 said:

I'm not saying all wood boats are effected, just that back in the day it was enough of a problem that ins. co.s started requiring boats to be bonded.

Click to expand...

I guess opinion and practice has shifted on this. Maybe still not unanimous, but certainly the majority of wood shipwrights and surveyors that I know and have read now say zinc the big things (rudder, prop, shaft, etc.) separately as needed, make sure you do not over-zinc, and let through-hulls float.

Insurance companies can continue to do what they want, but bonding through-hulls isn't required by ABYC so a surveyor shouldn't write you up if you don't bond.

Adding, just to make it clear in case it isn't: This advice is for wood construction only, and is a separate issue from bonding for DC or AC electrical ground, lightning protection, SSB radio counterpoising, etc.

If your ins co requires it and you dont do it, then your boat sinks, for whatever reason, they WILL deny coverage. Ignorance or not. May be that practice has shifted away from wood boats being required (all boats for that matter) to be electrically bonded, and I do agree with that. The only wood boat I've owned, a 44 foot Kulas sportfisher, was not bonded and suffered no ill effects that I could find. But, delignification is still a major concern, maybe not on your boat, or the neighbors, but on enough boats for the ins co.s to require bonding of underwater metal.

FWIW - My boat is throughly bonded "the old fashioned way" with a a copper strip up the center of the boat and lots of #6 copper wires from it to every hunk of bronze and both engines. It seems to have served the boat well for these years so I endeavor to keep the bonding in good shape.

Ken

kulas44 said:

If your ins co requires it and you dont do it, then your boat sinks, for whatever reason, they WILL deny coverage.

Click to expand...

Does your policy actually mention bonding? Mine doesn't; it just requires implementing the surveyor's recommendations and performing due diligence on maintenance. Which, given ABYC and USCG on this, doesn't require bonding.

The only wood boat I've owned, a 44 foot Kulas sportfisher, was not bonded and suffered no ill effects that I could find.

Click to expand...

Your experience is very common. Bonding seems to cause delignification more often than it prevents it. Like the USCG circular I linked to before says, "This cathodic protection of underwater metal hull fittings often causes damaging alkali delignification of the surrounding wood."

When I owned small 23' and 28' boats, I used my car/home insurance company and "bundled" my policies. I found out the hard way that they had no professional marine division and no knowledge of Coast Guard regulations or ABYC standards. Whatever the surveyor noted as a recommendation was mandatory in their opinion. (Change all belts and hoses annually.)

For that reason I switched to a company with Marine Insurance Underwriters and to date they have ignored surveyor recommendations or personal opinions that aren't based on Coast Guard or ABYC standards. (One surveyor recommended I replace all my Bronze through hulls with "Marelon" valves and fittings. If I'd had my old insurance company, it would have become a requirement.)


I'm sure the same would apply to bonding if that had come up as a recommendation in a survey.