Bonding System Questions

[AleCiotti]

Hi guys, after 3 days of intense research on the topic I'm finding myself with a couple of questions I can't find, I'm gonna preface by saying that I'm very new to this world. (the boat in question is a wooden boat)

1. Should I use a #6 AWG wire (both bonding and lighting protection) to connect every metal component on my boat (as of right now the old bonding system is a daisy-chain type), or just to connect the bonding bus to the sacrificial anode?
2. Should I connect Every metal component on my boat or just the ones in contact with an electrolyte (water)?
3. How should I connect the bonding wire to a metal component? I've seen a lot of photos but no one actually connecting it so i'm not sure about it.
4. I don't know where the sacrificial anodes in my boat for the bonding system are, I know there is 1 on the propeller + 1 on the propeller shaft and 2 on the keel (I suppose the bonding system to be connected there), so if you know of some other common places where a sacrificial anode for a bonding system could be, that could help.
5. as of right now the old bonding system is using a flat copper wire, but I haven't seen anyone using it so I don't think it's the best way to go about it and I'm looking to change it all, I'm gonna link some photos below:

[s/v Jedi]

First a couple points:

A bonding system involving lightning protection, which you need, must have a special bonding plate under water, in the area below the foot of the mast. This plate must be rated for lightning protection. Sacrificial anodes are not suitable.

For galvanic protection, you need a silver chloride reference cell so you can measure it and size the zincs accurately. You can have too little but also too much zincs. You buy it here: https://boatzincs.com/categories/too...electrode.html

Bonding for corrosion protection is only for underwater metals like prop, propshaft, brackets etc.

Bonding for lightning protection: if you have a metal mast, it must be bonded at it’s base with a wire that goes down to the underwater plate, without any sharp turns and never horizontal (as much vertical down as possible).
If you have a wooden mast, you need to bring the wire all the way up to the masthead and install a rod there.

There are multiple wire sizes specified. Do you have the relevant ABYC document?

[s/v Jedi]

Grab these files before they disappear.

[AleCiotti]

Ok, thanks for all the information! i will get an electrode so I can measure the correct zincs sizes.
I don't think that i have the ABYC document, i'm from Europe.

[AleCiotti]

Originally Posted by s/v Jedi

Grab these files before they disappear.

i did, will give them a good read, thanks! 👌

[GordMay]

Originally Posted by s/v Jedi

Grab these files before they disappear.

ABYC TE-4 LIGHTNING PROTECTION (2006)
ABYC E-2 CATHODIC PROTECTION (2013)
Added to the CF Library* [under ‘Red Tape’] - Currently Awaiting Moderation
* ➥ https://www.cruisersforum.com/forums/downloads.php

[s/v Jedi]

Originally Posted by AleCiotti

Ok, thanks for all the information! i will get an electrode so I can measure the correct zincs sizes.
I don't think that i have the ABYC document, i'm from Europe.

I am from Europe too but for the past 22 years sailed mostly around the Americas and used US based suppliers.

You may not be able to find a lightning rated plate in Europe. In that case simply buy a piece of solid bronze plate, about 10mm thick and 300x100mm size as well as two long bolts with flat, countersink heads, something like M8 or M10. Now bevel the edges of the plate using a grinder and drill two countersink holes for the bronze bolts. You need to solder these bolts in place using a map gas burner, flux and solder as used by plumbers. This must be watertight.

You bolt this under the boat with Sikaflex or 3M polyurethane. On the inside you use the long bolts as attachment for the bonding wires.

You can paint the plate with antifouling as long as it isn’t used for grounding the AC power system. Leave it bare otherwise.

[GordMay]

ABYC’s guidance on ground plates:
A lightning grounding terminal for a boat should consist of a metal surface [ copper, bronze, or Monel, not sintered, not bevelled, and not faired into the yacht’s hull] that is in contact with the water, having a thickness of at least* 3/16" (5 mm), and an area of at least one square foot (0.1 m2).

It should be located as nearly as possible directly below the lightning protective mast, in order to minimize any horizontal runs in the primary down-conductor.”
Studies indicate that the greatest advantage, for strike current dissipation, can be gained by providing the longest possible Sharp plate edge [as electricity prefers to exit via an edge], rather than surface area.
Therefore, a 2-inch wide, 72-inch-long rectangular strip plate is far more preferable, than a 12 inch by 12-inch square plate, even though both are the minimum 144 square inches.

* I would specify a grounding electrode strip at a minimum of 1/4" [6.35 mm] Thick x 2" [50.8mm] Wide, and 6' [1.83m] in length, to be fastened forward and aft, with two bolts at each end, to prevent twisting/warping.

[deblen]

Dynaplate?


https://ca.binnacle.com/Electrical-M...duct_info.html

[GordMay]

Originally Posted by deblen

Dynaplate?
https://ca.binnacle.com/Electrical-M...duct_info.html

NO - I would NOT recommend the use a Dynaplate, as a Lightning Ground Electrode.
They are made of sintered bronze, and designed as RF grounding plates for radios. Because of their porosity, they contain water, which could explode, when the heat [of a discharge] vaporizes the water within.

Use a Copper, Bronze, or Monel, strip, as previously described.

[Bowdrie]

Originally Posted by GordMay

* I would specify a grounding electrode strip at a minimum of 1/4" [6.35 mm] Thick x 2" [50.8mm] Wide, and 6' [1.83m] in length, to be fastened forward and aft, with two bolts at each end, to prevent twisting/warping.

Gord, I know it's easy to cross every "T" and dot every "I" and make sure everything is perfect.
But reality trumps perfection almost every time.
Having helped install a length of 1/4" copper on the stem of a boat, the idea of forming and installing a 6' piece of 1/4" x 2" copper on the compound curvature of a fiberglass hull and only securing it at the ends is braying at the moon for all but the most dedicated of masochists.
It ain't tinfoil, it required great effort and had to be secured at relatively close intervals.
Lightning will do what it wants no matter our lofty goals, we mortals can only do what we can with what we have, (or can reasonably acquire,) and call it "good enough" .
Put another way, as some famous architect said, "It's so easy to draw something that's so difficult to build".

[GordMay]

Originally Posted by Bowdrie

Gord, I know it's easy to cross every "T" and dot every "I" and make sure everything is perfect.
But reality trumps perfection almost every time.
Having helped install a length of 1/4" copper on the stem of a boat, the idea of forming and installing a 6' piece of 1/4" x 2" copper on the compound curvature of a fiberglass hull and only securing it at the ends is braying at the moon for all but the most dedicated of masochists.
It ain't tinfoil, it required great effort and had to be secured at relatively close intervals...

Indeed.
Any, required, intermediate fasteners can be in a single row.


Q: What's the difference, between fiction and reality?
A: Fiction has to make sense.

[s/v Jedi]

Originally Posted by GordMay

NO - I would NOT recommend the use a Dynaplate, as a Lightning Ground Electrode.
They are made of sintered bronze, and designed as RF grounding plates for radios. Because of their porosity, they contain water, which could explode, when the heat [of a discharge] vaporizes the water within.

Use a Copper, Bronze, or Monel, strip, as previously described.

Actually, besides the RF grounding plate, they also manufacture three plates that are rated for grounding and bonding, incl. lightning protection.

So three out of four are rated for lightning protection.

[GordMay]

Originally Posted by s/v Jedi

Actually, besides the RF grounding plate, they also manufacture three plates that are rated for grounding and bonding, incl. lightning protection.
So three out of four are rated for lightning protection.

Rated, by whom?
The Standard, D-8 , Giant, & Super Dynaplates are all made with a sintered porous bronze sphere construction; which I wouldn't use as a high energy electrode.
None of them meet the minimum requirement of 144 square inches of area, nor sharp perimeter edges.
➥ https://www.marinco.com/products/Bat...ent/Dynaplates

[s/v Jedi]

Originally Posted by GordMay

Rated, by whom?
The Standard, D-8 , Giant, & Super Dynaplates are all made with a sintered porous bronze sphere construction; which I wouldn't use as a high energy electrode.
None of them meet the minimum requirement of 144 square inches of area, nor sharp perimeter edges.
➥ https://www.marinco.com/products/Bat...ent/Dynaplates

The story about not using Dynaplates is targeted at the SSB ground plate that is made by Dynaplate and this is then repeated by everyone.

The thing is that the other products have a track record of dealing with lightning strikes without a single problem. In fact, there used to be a special version for lightning protection (which I have two of) and Guest documentation at the time listed the other models as “not for use as lightning protection”. Today, out of four models only the thin SSB plate has that label and the other three are all rated for both grounding and bonding applications. I guess they improved the manufacturing process or made them all thicker so as to only have the restriction for the large SSB plate.

We have had many lightning strikes and zero damage to the protection system included these plates. Also, they are ABYC compliant.

The surface area is larger than the plate because of the porous construction and the hard edges are not required for the bonding plate.

Lightning doesn’t need anything to travel… it will simply ionize the air to make a conductor on the fly. The only thing you need to do is provide a path that is safe for passing the charge without damaging the boat and make that path attractive enough so that the lightning strike will prefer it over the fiberglass/wood etc.

For a wooden mast that requires a lightning rod, a single sharp point is enough to attract the strike away from surrounding items 100% of the time, even when it is only 6” higher than the next highest point.

Once the strike travels down the protection system, something really bad must happen for it to divert because copper is much better than surrounding materials, but a bend to horizontal while the charge wants to go down to ground potential has been shown to cause side strikes to other materials causing damage. This is why other large metallic parts still need to be bonded as well… it’s for dealing with side strikes that carry part of the charge.

Once arriving at the grounding plate, the water is the only way to ground for the charge. One possible exception is when hooked up to shore power without using an isolation transformer (which is why all my reference diagrams have one).

For wooden boats or metal boats I would need to think about it more and I have no direct experience with strikes on those but for fiberglass I know from first hand experience that these protections are sufficient.

Edit: attachment showing lightning protection.