Removing gas from tanks

Mark,

Thanks again for the explanation. It makes sense. Yes, it was the fuel tank manufacturer's instructions which said to ground the fillers. Now I understand that that "works" when the boat is in the water, but not when it isn't.

As for grounding the motor leg, I was just thinking of a wire with a clip on one end and bare wire on the other end. I already have to do a bunch of routine things when filling at a gas station (get out fuel diaper, gloves, fuel treatment, log book, close cabin door, etc.) so I don't think it would be a big deal for me to add one more. It might be easier than touching the nozzle to the fuel filler cap and then finding a place to set the nozzle down (and then trying to reach it from in the cockpit - which is much more of a height difference on land). I have the traditional fillers that open with a key, which I like.

But just so I know my options, I now get that I could touch the nozzle to the closed filler, then put it down and open the fills, then fill. But let's say I wanted to do it the strap way (on land). Would that just be a length of wire that I could clip onto the engine (obviously on a bare place, maybe the end of one of the engine attachment bolts?) and then let touch the ground during the fill process? I think that would be easier for me, as I could do it in controlled fashion before/after I'm dealing with the pump nozzle. I would add it to my checklist/routine when filling on land. Would be small to carry.
 
Sunbeam,

The touch the ground with the filler nozzle before filling may produce a spark, which is why the fuel supply, and the filler access are closed. Any procedure in which the supply nozzle is touched to ground while the filler cap is open potentially could initiate a fire. I think you are stuck with touching the filler exterior (one hand on nozzle), opening the filler and removing cap (other hand), and then fueling using the first hand. Am I missing something?
 
AstoriaDave":500if0bd said:
Sunbeam,

The touch the ground with the filler nozzle before filling may produce a spark, which is why the fuel supply, and the filler access are closed. Any procedure in which the supply nozzle is touched to ground while the filler cap is open potentially could initiate a fire. I think you are stuck with touching the filler exterior (one hand on nozzle), opening the filler and removing cap (other hand), and then fueling using the first hand. Am I missing something?
Click to expand...

I get what you're saying. My question is, can the static be dissipated with a strap (and maybe then touch the nozzle to something else that is grounded), or does it have to be the closed filler cap? Touching the nozzle to the closed filler cap at a fuel dock is not a big problem (and my fillers are grounded when boat is in the water), because I can just set the nozzle down on the dock or etc. while I then get the cap off (at least if it is a floating dock or non-tidal waters). But it's a bit more of a problem at a "land" gas station because I don't really want to just drape the nozzle into the cockpit (potentially dripping gas), but setting it on the ground is five feet down and I then can't reach it. So I was just trying to think of a better way. Maybe there isn't one.
 
I think that taking the same care that you use when filling your car/truck when filling the boat is precaution enough. I don't think that putting gas in my boat is any more dangerous than putting it in my car.

The areas when and where most people boat (i.e. near water) are generally humid enough to prevent the build up of static charges. In the US, only in the southwest during the winter months do I expect that this is much of a concern.

You probably dissipate any static charge in the fuel system when you touch it to open the cap.
 
ssobol":140cvgtc said:
You probably dissipate any static charge in the fuel system when you touch it to open the cap.
Click to expand...

Well there is a point. The "key" I use to open the caps is metal. Maybe that dissipates the charge before I fill anyway? Or maybe not since the boat is not grounded when on the trailer.

One thing I still wonder about though: You say it's no more dangerous than filling a car, but is the car grounded to the ground? If so, that would be a difference. If not, then maybe it's the same when filling the boat.

I do tend to fill in the dryer climates fairly often (at land stations I mean).

Obviously some folks aren't going to give it a second thought. And if there is no reason to, maybe I won't either. But OTOH, the consequences of a gasoline fire (even if super rare) are pretty large. And too, I take it as an opportunity to learn something more about how my equipment works.
 
We seem to have a boat catch on fire every year at the fuel dock where I live, which is a very humid rainforest. No disrespect to those who don't think this is something worth worrying about, but it is.
 
I think that it all depends on which item is carrying the charge. Getting out of a car, the person usually generates the static charge with clothing against upholstery. Some then say that they get shocked when they close the door. The vehicle is acting as a ground. If, instead of the door, the first thing that they touch is the grounded gas nozzle with fumes coming out from the tank, that's when the usual gas station excitement starts. Here is an example. You can see that she slides around on the car seat, gets out without touching the car, and reaches for the nozzle. https://www.youtube.com/watch?v=tuZxFL9cGkI

And sometimes it's the vehicle itself that generates the static charge. That's when the anti-static straps come into play. I never have understood why a rubber strap hanging down from your fender does anything more than your rubber tires, but there's probably a lot that I don't understand about static electricity. Like why is it that the best way to produce it is to rub an ebonite rod (a great electrical insulator) with a fiberglass cloth (also a great electrical insulator)?

The regulations that require grounding a boat's fuel system are there because somehow the system can generate a static charge. The nozzle is grounded and if the system isn't there is a spark. If the fuel system is "grounded," but the boat is out of the water, then it isn't really grounded and the same problem could occur.

If you need to be in the boat when it is on your trailer, then I can see that it gets complicated. If your tanks are properly grounded (when the boat is in the water), then your most accessible ground with a boat on a trailer is probably the fin anode under your anti-ventilation plate on an outboard. An alligator clip on the anode with a length of wire touching the ground should work.

The regulation that I found said that tanks and fills should be bonded with green 10 AGW wire. That can handle quite a jolt. Knock the nozzle right out of your hand. Again odd that a rubber anti-static strap works on a car.

Mark
 
When you obtain a static charge by moving around your car you usually will dump it when you touch something metal in the car or something else that is grounded like the gas pump. Unless you are very careful you will probably discharge inadvertently by the time you pick up the gas nozzle.

IMO, if you are concerned that the boat is carrying a charge you can probably dump it by touching the filler while touching the trailer (metal part). If it does not go to ground via the trailer itself, it will flow through the tow vehicle (we demonstrated that by getting a shock when getting out of the car).

Once the nozzle is in the filler you are grounded through the pump.

On a C-Dory you could put a ground wire from the fuel system ground to either the brass rub strip or the bow eye directly. The system would then be grounded through the towing safety chain through the tow vehicle.

Of those fires that occur at the dock in the rain forest, how many of those are actually the result of static electricity and not something else like maybe spilling gas on a hot engine?
 
Here is what I found with a quick Google. I had the ABYC gasoline fuel system standard in hand when I did my tanks, but didn't have it to hand now. I do have metal fillers. They don't discuss trailer boats not in the water. I used green wire to ground the fillers - I think #10 but it may have been #12. I did test the resistance after installing them.

They discuss that fuel going in can itself build up static. So perhaps that's why I had never heard of touching the fuel filler cap before unscrewing it?

I'm not saying how each person should do their system. I'd just like to know if best practice would be to do something specific on my boat in two situations, on the trailer and in the water. If I don't have to do anything before opening the fuel caps (with the nozzle that is), so much the better as that would be a bit clumsy.

United States Coast Guard and Environmental Protection Agency
Compliance Guideline -How to Comply with the Law-
Fuel and Emissions
Prepared by the American Boat & Yacht Council, Inc. 613 Third Street, Suite 10 Annapolis, MD 21403 (410) 990-4460 www.abycinc.org
© 2011 American Boat & Yacht Council, Inc.

IT’S THE LAW - USCG: 183.572 Grounding.
Each metallic component of the fuel fill system and fuel tank which is in contact with fuel must be statically grounded so that the resistance between the ground and each metallic component of the fuel fill system and fuel tank is less than 100 ohms.
Fuel flowing from the dispensing nozzle into a fuel tank is a potential source of a static electric charge which could cause a spark between the dispensing nozzle and metal component of the fuel tank fill system. To prevent such a spark from occurring, metallic components of the fuel tank fill system and metallic fuel tanks must be grounded.
Grounding or bonding may be accomplished by connecting the metallic components electrically by running a wire from one component to the next, and so forth to the boat's ground. Grounding can usually be accomplished by a connection to the common bonding conductor or the engine negative terminal.
If the fuel tank deck fill fitting is nonmetallic, and nonconductive hose is used as a fill pipe, there is no need for grounding the fill fitting. Chrome-plated plastic fill fittings are treated the same as metallic fittings.
NOTES: 1. If a metal hose attachment fitting is used, it must be grounded. 2. Fill cap retaining chains need not be grounded.
 
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