Bonding System 101

[Forkliftt]

Greetings. On CarDude's recent post on his AC, bonding the unit was mentioned. My boat appears to be running "hot"- meaning the valves on the fuel tanks have recently gotten a bluish tint to them. During a bottom job in February all the zincs were changed. This included the block zinc on the transom, rudder zincs and egg zincs on the shafts. I also run "sweeps" on the shafts inside. I have a diver every two months that cleans the hull and replaces zincs as needed- though none have been replaced to date. I'll get with him to see if what's under is consuming as needed. My questions...

*What is the best held practice for replacing the bonding wiring? Do I want to create a "daisy chain" from component to component? Is the shortest run possible my goal? The wiring I see is strung pretty tight. Possibly just to lower costs. I would prefer to add "curleys" to my wiring where beneficial.
*What size/ type wire is recommended? What terminals (eyelets) do you recommend? Best crimping method? Do you suggest an anti corrosion spray?
*No debate here needed- but should I bother with bonding the couple of unused thru hulls I now have? Fuel tanks (black iron), water tanks (SS) are obviously needed. How about the AC units? What other components??

Again- no debates needed- just strongly held opinions. I'm a big boy and can probably make informed decisions on my own. Thank You.



1983 Present 42 Sundeck
Twin Lehman 135's

 

[Capt.Bill11]

You either bond everything or nothing.

Usually you use #8 tinned wire. Use good quality (Anchor) crimp on ring terminals that have heat shrink covers. Then paint/seal the connection point as best you can with heavy dialectic grease or liquid electrical tape, etc.

You can daisy chain where is easiest to do and home run else where.

 

[DavidM]

I agree 100% with CaptainBill.

David

 

[bayview]

Why Bill said but you can measure what your current system is doing. You also don't say what the condition of the zincs were prior to change.

 

[Forkliftt]

Prior the zincs had normal wear. After the yard installed the block zinc I had removed it and cleaned the contact areas a bit more with a wire brush. The existing copper I see looks dark- prefer a revamp now and check it off the "list". Preferred source for wire and terminals anyone???


1983 Present 42 Sundeck
Twin Lehman 135's

 

[GregBrannon]

You either bond everything or nothing.

What determines whether one chooses the all or nothing path?

 

[Capt.Bill11]

What determines whether one chooses the all or nothing path?

Two schools of thought. Bond everything or leave all underwater metal fittings un-bonded from each other.

As I recall Caulder's book discusses the how's and whys.

 

[Brooksie]

I am of the "don't bond school" and have never has a problem with any of my boats in 50 years on the water. Boats however were all moored and had no AC systems.
My practice is 1) why create cells by stringing wires between metal objects which may be dissimilar when by themselves they would be fine. 2) why connect battery ground to bonding, and by extension the bilge water, so it can be ready to react with a positive leak. 3) use a Drivesaver to isolate the engine from the shaft. 4) zinc dissimilar metals like SS shafts & bronze props, struts, rudders. 5) never use a pump switch that puts wires into the bilge water.