Hello Andy,

What most people do is to run a wire from item to be grounded (tank or mast) to the keel bolts in the bilge. I would suggest a 12 or 10 gage-insulated wire (nothing special). You just need a good metal contact at both ends. On the tank you could use one of the bolts holding the fuel gage in the tank. You can buy an "eye" electrical connector that crimps to the wire that has a hole for the bolt. It is best to use a proper crimping tool so the connector is firmly attached to the wire. Strip the wire just enough for a metal to metal connection on the connector. You will use the crimping tool for other maintenance items over time. For the keel bolt connection you should strip four inches of covering from the wire and sandwich the exposed wire tightly between one of the keel nuts and the washer underneath the nut. You should wrap the exposed wire around the bolt. If you remove the floorboard at the bottom of the stairs you can see where all of the other wires going aft have been run on the starboard side. You may be able to snake the wire under the engine and keep it out of sight.

All of that said, I have no plans to ground either my mast or my fuel tank. There are various points of view on grounding items on a boat. Many people believe everything should be grounded. When you do that however you provide a better path for electricity to travel through the boat and hence you may actually attract lightning. By not grounding you don’t provide a particularly good path and may avoid a strike. Fiberglass (silica) or most non-metallic materials are poor conductors of electricity. Diesel fuel is very safe when compared to gasoline and gasoline fumes and in my opinion poses very minimal risk of explosion or fire.

Two years ago I took lightning strike at the dock when I was not on board. The only damage I incurred was a fuse in my instruments. The only way I knew I took a hit was the mast acted like a capacitor and stored a slight charge. Needless to say in an electrical storm no one (you or your crew) should be in contract with the rigging or anything metal.  Shorten sail, get life jackets on, and get everyone in the cockpit.

Hope this helps,

Bill

Hello Andy,

I think you are going have to pose your question to an electrical engineer with more knowledge of the technology and regulations. I believe the issue the regulation is trying to address is discharging static electricity during fueling. This sometimes occurs at gas stations when cars are refueled, resulting in a fire or explosion. It is my understanding that just taking the ground to the engine is not sufficient since the charge is not dissipated unless the engine itself is grounded directly to the water. Even going to the keel bolts is not a true ground as lead in the keel is not a particularly good conductor.  It is my understanding that to get a good ground one needs to go directly to a plate on the outside of the hull that is in the water.  I don't know of any sailboat boat manufacturers that do that.

I would suggest you contact a company called Polyphaser at http://www.polyphaser.com/service.aspx?type=2"> color=#810081http://www.polyphaser.com/service.aspx?type=2 They are into grounding all types of electrical devices. Let me (us) know what say. They know the technology very well and may know the specs.

Bill

Quote: Originally posted by Cayuga on 24 April 2009

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This may be one of those things that really doesn't matter that much, especially for diesel, but my surveyor noted it and now my insurance company is requiring a fix. I did some web searching and found that grounding the fuel tank is in the ABYC regulations. Also found it in the Transport Canada regulations:

7.1 Application ^

7.1.1 This section applies to all gasoline and diesel fuel systems for all small vessels, except where indicated otherwise.

7.9 Grounding ^

7.9.1 Each metal or metallic plated component of the fuel fill system and fuel tank that is in contact with the fuel must be grounded so that its resistance to the vessel ground is less than 1 ohm.

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