Filling the Fuel Tanks

[mastreb]

You are going to generate a spark with a plastic fuel tank how?

Various plastics build up a static charge. Ever rubbed a balloon on your hair? That's a good example.

[mastreb]

It's far more dangerous to lift a 12 gallon fuel tank from the ground into the cockpit of a Mac than it is to fill the fuel tank in place in the fuel lockers on the back of the boat.

The boat is not grounded, so there's no risk of discharge as long as the tank and the person are both entirely within the boat. The problem comes from a sudden completion of a ground circuit while fuel is pumping. This happens for example when a person is moving around and they are grounded or touch something else that's grounded. If you're entirely in the cockpit of the boat, this can't happen. Leaning over a powerboat to fuel it is a different matter.

Cars are not grounded, and yet static discharge fires at gas stations are extremely rare. It's so unlikely to happen that it doesn't warrant serious concern, laws in various places not withstanding.

The risk of dropping a heavy fuel container and spilling fuel all over the place is much much higher. I leave my 12 gallon tanks strapped into the lockers permanently, go to truck stops, and climb into the cockpit to fuel.

Matt

[pokerrick1]

It's far more dangerous to lift a 12 gallon fuel tank from the ground into the cockpit of a Mac than it is to fill the fuel tank in place in the fuel lockers on the back of the boat.

AGREED

Rick

[dennisneal]

Maybe I'm missing something.

I usually fill up our tanks at a gas station enroute to the marina. But, I've also filled up at a marina. Frankly, I barely thought about static electricity starting a fire. The procedure appears to be the same at either location. I would think that the hull provides a great deal of electrical insulation and will prevent a spark.

[pokerrick1]

Maybe I'm missing something.

If you are - - - I am too

Rick

[Crikey]

The hull, being minimally conductive (think of a lightning strike) is grounded through contact with the water. A car or trailer is capable of holding a charge because the rubber tires are fairly good insulators (my earlier key spark example), and in particular newer tires are better than old ones in this regard. This was done on purpose by the tire manufacturers some time ago to eliminate travel sickness through positivr ion buildup in the car ( remember the rear bumper straps?).

You can hold on to, and touch other grounded things to do the discharge before you apply the fuel hose on a statikky day - but if you've got the cheap chinese plastic formulation, your lapse of memory is not going to do you a hull of a lot of good, when surrounded by a fuel air explosion.

Sorry for the negativity!

[David Mellon]

My two 12 gallon tanks are strapped into their lockers and are not portable. I fill them at gas stations on my way to or from the marina as well. Here behind the California Curtain we have the most draconian laws outside of The Vatican. There are no rules here against filling my built in tanks on the boat while on the trailer. I use about 16 gallons on a typical trip from South Shore Launch Ramp near The Queen Mary in Long Beach to Catalina Island which leaves me a respectable amount of spare fuel in case of emergencies like polar reversal or all the satellites my GPS uses for fixes falling from the sky.

[seahouse]

Well, if nothing else it looks like this thread has been an eye-opener for some. That's a good thing.

But, at the same time it looks like some have willfully chosen to remain in the dark and in a state of denial. I don't think that's OK at all. Mainly because it unnecessarily endangers the lives of innocent people that may be nearby. The data are there, the dangers of static buildup and spark discharge are very real and well documented, and there is nothing hocus pocus about it.

There are enough variables that are totaly out of our control, why take a risk that you don't need to take? Especially when the downside can be grave.

[seahouse]

I would think that the hull provides a great deal of electrical insulation and will prevent a spark.

The problem is precisely that- the insulation. It's insulation that allows the buildup of charge. Without a non-conducting surface you wouldn't have any static electricity.

Static electricity won't build up in a conductive environment because the difference in electrical potential would be constantly dissipated and neutralized to be zero. You actively establish such a conductive environment when you ground an object, and then another, making the electrical potential between the two objects (say a fuel nozzle and a gas can spout) zero, the same as the ground.

[jschrade]

I'm getting really worried about an electric spark off my plastic gas tank in Florida. It's right up there with a great white attack in our marina or even better: end of the world predictions.

Feel free to fill your portable jugs in your boat at the gas station or gas dock. In the marina may be a different matter as mentioned earlier as they are not equipped to handle a spill like a gas dock.

Jim

[mastreb]

Well, if nothing else it looks like this thread has been an eye-opener for some. That's a good thing.

But, at the same time it looks like some have willfully chosen to remain in the dark and in a state of denial. I don't think that's OK at all. Mainly because it unnecessarily endangers the lives of innocent people that may be nearby. The data are there, the dangers of static buildup and spark discharge are very real and well documented, and there is nothing hocus pocus about it.

There are enough variables that are totaly out of our control, why take a risk that you don't need to take? Especially when the downside can be grave.

Turns out you're correct about the data being available. Here it is: http://www.pei.org/

Salient facts: Americans pump gas 12 billion times per annum. There are approximately 120 gas station fires per year attributable to static electricity. Your odds per fill-up: 1 in 100 million.

Some other statistics:

Odds of winning a million dollar prize in a lottery: 1 in 20 million (five times more likely)
Odds of being struck by lightening: 1 in 400,000 (250 times more likely)
Odds of dying in a car accident on the same day in which you filled up your boat tank: 1 in 1,825,000 (50 times more likely).

There was one very important takeaway from the stats however: 94% of people involved in a static discharge fire at a gas station were wearing rubber soled shoes. So don't put your boat shoes on until after you fill your tank.

As for me, I'll change my shoe habit and never worry about this again.

Matt

[Catigale]

Okay got it.

Thread summary ...no rubbers, fewer sparks.

What are the odds of being killed by a falling vending machine btw?

[dca81]

What the chances??? Member of my vintage race club had a flare up when he was refueling his Jag with a five gallon (plastic) gas can. Thought it was caused by static from the nylon jacket he was wearing. Fortunately with all the fire extinguishers in the pit area the flareup was immediately extinguisher with only a few minor burns and a ruined jacket. Lesson, maybe wise to have a fire extinguisher "immediately available" for those of us (including me) that play the odds.

[mastreb]

What the chances??? Member of my vintage race club had a flare up when he was refueling his Jag with a five gallon (plastic) gas can. Thought it was caused by static from the nylon jacket he was wearing. Fortunately with all the fire extinguishers in the pit area the flareup was immediately extinguisher with only a few minor burns and a ruined jacket. Lesson, maybe wise to have a fire extinguisher "immediately available" for those of us (including me) that play the odds.

Well, here are those odds:

Number of people in the average person's circle of concern (coworkers, family, friends--people you spend some time with): 100..200.

Number of people you know by name: About 2000.

Odds you know of someone who has had a spark gas flare-up: 1: 50,000

Members of this board (bald-faced guess): 10,000.

Odds that someone on this board has heard of someone who has been involved in a spark gas flare-up: 1 in 5.

So, pretty likely actually. It's this effect (large-group statistics) that make improbable things seem a lot more likely than they actually are. It's also why boards like this are so useful--the same effect makes it likely that someone has already performed whatever kooky modification to your boat you want to attempt.

Also, according to the U.S. Consumer Product Safety Commission there were 37 known vending machine fatalities between 1978 and 1995, for an average of 2.18 deaths per year. Your odds: 1 in 200,000,000 million of being killed by a vending machine, or half as likely as being involved in a spark-gas flare up.

Matt

[Catigale]

heh heh...

I brought the vending machine thing into the fray from an earlier thread...

Moreover, according to the U.S. Consumer Product Safety Commission there were 37 known vending machine fatalities between 1978 and 1995, for an average of 2.18 deaths per year. Over the past decade there were a total of six recorded shark attack fatalities in the U.S., for an average of .6 deaths per year. Ergo, barring a drastic reduction in the frequency of vending machine accidents since 1995, vending machines are indeed more deadly than sharks by a factor of almost four.