Kevin,

I am in the process of restoring a pontoon boat and doing some research on the fuel system.

If using a plastic fuel tank with rubber hoses that go from the tank to the metal deck fill on the side of the railings, should you ground the metal inlet to eliminate any static charge?

The U.S Coast Guard’s Boating Safety website says that any portion of the fuel system that is metallic has to be grounded. This confuses me because if you ground the inlet, it will essentially ground the entire marine electrical system, which could potentially cause corrosion issues.

Any advice you can give me would be great.

Thank you,

Bill

Hi Bill,

It is important to ground all of your boat’s metal fuel fill components together to prevent accidental, static discharge.

When fuel flows down a hose, the swirling action creates a static buildup. If the fill is not grounded to the tank, there is a change of a static discharge when the pump is removed from the fill which can cause an explosion. If the fuel fill is made of plastic, this static ground wire is not required.

Galvanic corrosion (the corrosion that occurs when dis-similar metals are electrically connected) will not be a concern. To cause galvanic corrosion, the two pieces of metal need to be electrically connected and submerged in the same body of electrolyte (water). If your boat’s fuel fill and tank are continuously under water, you have more serious concerns than galvanic corrosion.

Please let me know if you have any other questions,

Kevin

Kevin,

Thank you for quick response.

The way the boat was originally wired, there was a tank ground wire from the filler to the negative terminal of the battery.

The tank is plastic so I do not think bonding them together would discharge the static energy. The only metallic portion of the fuel system is the filler.

Is this the correct way to go about this?

Again, thank you for your help.

Bill

Bill,

Beyond connecting all metal components in fuel system that can come it contact with fuel, the system must also be connected to the boat ground.

The full intent of this practice is to give a low resistance path back to ground – metal fill – wire to tank – tank – to ground on boat – ground connected to metal underwater gear – boat in water – that will help prevent static discharge buildup.

• If your boat fuel tank has a fuel gauge sending unit, connect the static ground to the sender and the sender ground to the battery negative/ground bus.
• If your boat does not have a sender, connect the static ground wire directly to the battery negative/ground bus.

Hope this helps,

Kevin

Kevin,

This clears it all up.

Thank you very much for your help.

Bill

Kevin,

I am currently restoring and repowering a 20′ Bertram.

The boat is a stern drive with both batteries in the motor box. I have already purchased an automatic smart battery switch and an eight switch marine electrical panel.

This boat helm is very far forward. The boat will be used exclusively in salt water and I want to have a very “heavy duty” boat wiring job. All the equipment will be run to the forward helm and some accesories like

1. Bilge pump
2. Diaphragm pump
3. Washdown pump
4. Bilge blower
5. Navigation  lights

…will be needed to run back to the motor box. All other accessories will be mounted near the forward. helm.

Here are the other accessories on the marine electrical system:

• Stereo
• Boat horn
• Engine room lights (also run to the stern)
• Gunnel lights
• GPS
• VHF

I need a harness to accomodate all of this.

Your thoughts?

Thanks.

Marshall

Hi Marshall,

To do this job correctly, I would recommend that you build a completely custom boat wiring harness. The best place to start is with our wiring size calculator. Use this to determine what size wire your components require along with the size of the panel board feed wire.

Tinned wire in standard boat wiring colors and most sizes is available on our sister marine wiring site.

Good luck with the project. Please send pictures of the electrical portion of this restoration and we will post them on our site.

Thanks

Kevin

Hi Kevin,

I have a 1978 30′ Tollycraft sedan. My question is in regards to bonding.

My boat has a fiberglass hull, twin gas motors, two stainless steel fuel tanks, twin direct shaft drive, twin rudders, battery charger, isolator, four batteries with two boat battery switches, electronics (VHF, GPS, Fish/Depthfinder), 120 volt fridge, 120 volt water heater, 12 volt lighting.

When working on the boat, I noticed a lot of the marine wiring that appears to be old bonding wires is old and has either bad connections or has completely broken away from the parts it was connected to.

The boat was recently hauled out and new zincs and a new grounding plate were installed. What is the best method for bonding (wire size, methods for attaching, one main bond wire that others are connected to, or each individually bonded, etc.)?

I’ve seen various articles on bonding but remain not completely clear on the correct way to bond the boat and make sure all grounding has been done correctly.

Please explain.

Thanks,

Chuck

Hi Craig,

Here are the current ABYC standards for marine electrical systems. Please check out Page 31 and 32 which spell out how to bond your system.

Once you’ve checked the specs, please let me if you have any other questions.

Kevin