Anode Bonding Wiring Questions

[catalinajack]

I have decided to replace the green 6-gauge non-tinned wiring. Most of the ring terminals are heavily corroded. The terminals are all plain crimps (no heat shrink). There is no way to tell how deep the corrosion extends into the insulation so out it goes but no doubt it is present.

My questions are about the grounding points. My through hulls are all wired together of course but I just do not understand the grounding tie-ins on board this boat. There are two wires that are attached directly to the hull near the sea chest. There is another wire that is attached to the flat copper banding that makes its way all the way to the upper helm. I assume that this copper band is attached to a grounding plate attached to the hull. There are also wires that go to the engine.

1. Should I retain all three of these grounding points?
2. Should the engines be including in the bonding system?

 

[angus99]

John, you’re likely to get a variety of answers. I completely replaced the bonding system on Stella under the guidance of an ABYC electrician. On our boat, the two wires you describe as attached to the hull terminate on the sintered bronze grounding plate that was used for the shortwave (now removed).

If you have the copper boding strip running the length of the ER, it’s important not to attach bonding wires with self-tapping screws. They can vibrate out. I drilled holes in the copper, tapped them and used lock washers on all the attachments. I was also I advised to have no more than two components daisy chained before attaching to a ground.

All the bonding wires are led to the transom where the main hull anode is mounted. Pretty sure I used #8 wire on individual components and #6 to tie the the main copper strip to the collection point aft. I bought a couple of silicone bronze bolts etc to replace the stainless bolts that were looking pretty tired. Don’t forget to bond the bronze stuffing boxes.

Unfortunately, I’ve slept since I did this and can’t remember exactly how the engines factored in but I’ll be glad to look this weekend when I’m at the boat (not bonding).

Good luck.

 

[CharlieJ]

Post #2: +1

 

[Comodave]

I am redoing my bonding system also. I am using green #6 for everything. Heat shrink connectors on all connections. My engines have 0000 cables to the grounding bus bars. The bonding system is also connected to the grounding bus bars. I have some small bus bars in areas that have lots of connections so the connections go to the bus bar which is connected to the main bonging system. I have one of the sinistered bronze plates on the bottom of the hull that I assume is from a previous short wave system. I plan on removing it next winter when I pull the starboard engine and glassing the holes closed. Does anyone see any other reason for the sinistered bronze plate?

 

[Ken E.]

I have one of those plates too. I think it's an orphan from an old SSB radio that's long gone.

 

[angus99]

Does anyone see any other reason for the sinistered bronze plate?

I’ve kind of wondered if it could be connected with heavy cable to a lightning rod or static dissipator (or whatever it’s called) on the radar arch. Haven’t any idea if that would work though.

 

[Comodave]

It might work as a lightning ground if it was connected to anything. Mine is connected to the bonding system but I don’t see any other connections. I am going to get rid of it next winter along with 2 unused transducers. I got rid of one transducer this winter and the water intake for the old head. I put in a Marine Elegance head this winter so the intake through hull was no longer needed. In total there were 3 unused transducers, now just 2.

 

[catalinajack]

I think I may be a bit ignorant here. Here Iwas thinking that the bonding system needed to be grounded to something like a bronze plate used for a SSB radio. Now I get it, I think. Iems that need to be part of the bonding system are to be wired to the main transom anode. Is this correct? Not grounded otherwise. I am so dazed and confused. Help!

 

[catalinajack]

I think I may be a bit ignorant here. Here Iwas thinking that the bonding system needed to be grounded to something like a bronze plate used for a SSB radio. Now I get it, I think. Iems that need to be part of the bonding system are to be wired to the main transom anode. Is this correct? Not grounded otherwise. I am so dazed and confused. Help!

Belay what I just wrote. Just read a Steve D'Antonio artcle on boat bonding. I do need to rewire many of my thru-hulls. Since I have a copper strip running throughout my boat, including to the upper hem, I can attach bonding wires directly to the strip at any convenient point, the shorter the better. I have a number of connections to do very close to each other as I have a sea chest for most of my thru-hulls. My plan is to use a bus bar wired to the copper strip with the bonding wires terminated to the bar rather than having a dozen or so wires attached directly to the copper strip. Good plan?

 

[angus99]

Yes, for the bonding system to work, underwater metals must be electrically connected to an anode which will sacrifice itself and protect the other metals in the circuit.

Lots of good info here from our own Steve D’Antonio: https://stevedmarineconsulting.com/wp-content/uploads/2014/03/BondingSystems138_05.pdf

(Sorry, John, just saw that you’d emailed me.)

 

[Comodave]

It would be easier to have a bus bar near the copper strip and make 1 connection to the copper strip from the bus bar rather than trying to make a bunch of connections to the copper strip.

 

[Redhook98]

I have no bonding system at all in my MT. There is a copper strip along both sides of the keel, but all lines to thru-hulls have been removed at some point of their lives. No corrosion issues at all. The two camps on this are: 1) Absolutely everything needs to be bonded, or 2) Bond nothing. Seems there are great benefits to both.

 

[OldDan1943]

When I bought my American Tug 34/36 it had the "plastic" thru hull valves. That I did not like. I opted to change over to bronze. With this in mind, I had the yard redo the bonding system.
I am glad I had that done. BRIGHT SMILE