Polycraft static electricity

[cheno]

Have just picked up my new polycraft 455 centre console :))
and have noticed that they tend to generate a bit of static electricity. Do you guys earth them when you fill the internal tank? I know some people with glass boats do it.

Dont really want to blow myself sky high at the servo :-[

[FLATHEAD1]

I have had my polycraft for over 12 months and do not recall ever having a shock from static electricy build up.

My be you possibly store it in a place which may enduce electricity build up.

Try earthing it. Use a jumper lead clamp to the bow rail and to an earth point. See if that works.

Best of luck
FLATHEAD1

[basserman]

i too have never had a stadic shock for being in a poly as yet!
isn't the intrenal tank also poly?

[Brett_Finger]

sorry,
never been nailed by a poly,could be you yourself hold a good amount of charge in your own body and the ploy movement of your skin on the hull can at time produce a charge. (balloon rubbed on ya shirt then lift ya hair up type thing. :-/)

it's a newie on me either way mate.
Hookin,Brett :)

[cheno]

no worries guys, must be my weird physiology then ???

I was concerned when I leaned over the back of the transom and touched the steering cable which then earthed on me creating a spark.

It will be a while before I get the boat finshed and fuel into it anyway as I'm yet to find a suitable power plant for it. Probably will get a secondhand 60hp two stroke until I can decide on (and afford) either a 4 stroke or a direct injected 2 stroke.

[SeaHunt]

Well be careful, a static spark is certainly enough to set off petrol fumes. Might be a good idea to earth it in some way (just use yourself , no shoes) before you reach for the fuel nozzle. You heard about the guy who was filling his car and had a mobile phone on his belt. It rang and a fire ball erupted, nearly burnt his nads off. :P

[NQCairns]

Bit of a worry your story cheno :o :o but a great question. On occasion filling the little 25L poly tank in the back of the car the servo operator has stopped the pump and made me place it on the ground to continue filling? Your boat is just a bigger tote tank :o. What is the go?

My ally boat is earthed to the trailer via the winch but the entire rig (car and trailer) is not earthed because of rubber tyres?

Last week I was inside a fibreglass boat useing a belt sander when I caught the powercord, flames and sparks everywhere, cut the cord in half and the earth leakage safety switch didn't trip or any fuse blow :o.

Should a person only fill from within the boat?? If I filled the polytank from within the car would the operator need to turn the pump off? Should a person wear rubber shoes when filling to avoid any earthing and therefore a spark? Anyone know how the physics works?

Cheno I would be frequenting the full service stations for the first couple of months ;D ;D

[gif]

There was an issue on this board about static and BP refusing to refuel boats at a few test sites - which they quickly withdrew.

This was about 6 months ago, so I did some research for Nugget / this board and ended up as far as contacting BP Head office.

I also posted all the safety advice on here. # Some I will redo below


As I was personally interested in getting a Polycraft #I #called the technical guys at Rotathene #- the manufacturers of the material used by Polycraft. # ( I worked for an oil company years ago and had some knowledge of the topic).

It seems the boats are fine. # # It’s the fuel that is dangerous. #

This is the time of year, with dry air that will mean more static. # #I got a zap last week from my car.

Even metal boats are not earthed. # Why? # You do not connect the negative to the chassis as you would in a car - because then you set up a circuit when in salt water #- and start to dissolve the Aluminium! #Besides #- they are all insulated by the tyres #- that’s how you can build up a static charge. # Nothing to do with # Poly vs. Fibreglass v Aluminium.

Poly boats don’t conduct - so that’s nice – less chance of a short in the wiring. # # #They have additives and don’t particularly build up a static charge. # Mind you anything can. #Anything.


There are some plastics that are particularly dangerous with fuel - because they build up static too easily. # Yet other plastics are the ideal fuel tank. #Polycraft material is in between. # #Not a static worry #- but if you tried to make a fuel tank out of it – the fuel would eventually soften the plastic.

They could make the boats out of diesel grade or even acid grade plastic - but they would be heavier and cost more. #The red plastic tanks are blow moulded – so they are cooked under pressure making a much more dense plastic. #The plastic has different molecular joins #- meaning nothing penetrates.

Bottom line with static is to remove the red plastic tanks from the boat and fill them on the ground – so they are earthed. # #Touch the boat with your hand - if you get a zap be pleased with yourself! Then touch the hose nozzle to the outside of the tank before opening it. # Filling on the ground has other benefits – any spills don’t go inside the boat.

No way I’m careful #! # # BS # # because EVERY time you fill you spill - spill vapours that is. # # Pumping petrol in pushes out vapours. #Sometimes you can see them. # Sometimes not -#but they are always there.

Actually #Petrol does not burn. # # But petrol vapours #- a mix of fuel and air burns like crazy. # #You need 3 elements for a fire. # Fuel, Oxygen (air) and a spark.


So lets go back to the scenario of filling the little red tank in the boot or the boat. # You fill the 20 litres #- and push out 20 litres of vapour into the boot/boat space. # #Being heavier than air it sinks #- and stays inside the boot well or boat. # # Now it is mixed nicely with air – just waiting patiently for a spark from the indicator light or some spark inside the boat. # #So next time you turn left the boot lid blows off. #

Get the picture? #So always fill outside with lots of air around to disperse the vapours. # Fuel is the same inside an engine as outside. # Too lean or too rich and it wont go. # #So if you have to make vapours (as you do when filling a tank) # try to get them to be lean as quick as you can. # #Any fuel spills, even just a few drops, I disperse with water, before the tank goes in my boat. # #

Finally – if you do get a fuel spill on board turn off the electrics before you do anything else. # # Bilge pumps #- perhaps operating on automatic #- are not spark proof motors! # (woops – bang)

I know safety is boring #- sorry for the lecture # But who wants to be injured when we went out to have fun?

Hope this helps.

Gary

[SeaHunt]

You dont need to connect to earth as such to get a electrostatic discharge. As long as one object is more highly charged than the other the electrons will flow. For example on a dry day if I drag my feet around on the office carpet and then touch the door handle , it nearly zaps my arm off , you can feel it up to your elbow.. The door handle is metal , but it is not earthed in any way, wood all round.

[cheno]

yeah thats right Sea Hunt, simply the act of touching a metal object (earthed or otherwise) will lead to a spark. Thus its a build up of a net positive or negative charge in your body rather than the boat itself that is the issue.

With respect to building that net charge however it is caused by the movement of two INSULATING compounds against each other (eg you and your insulating boat). Because my boat is made from an insulating material, when I'm rolling around inside working on it i have the potential to perhaps generate more static potential than if I was inside a tinny.

So for my money it will be case of ...touch metal on boat to eliminate body charge, THEN open tank and fill fuel.

[Outsider]

Great post Gary with some good data.

Mobile phones are dangerous for the same reason as other electrical devices - sparks caused by the movement of the battery pack on the handset or sudden surges in voltage when calls are made and received igniting fuel vapour - not the radiation the unit emits.

I know of 2 occasions since 1st Feb where vapour has been ignited on a forecourt due to incorrect filling techniques by a member of the public - namely filling containers that were not placed on the ground in a ventilated area or "splash filling" a container of greater than 25L (deliberately) at a facility not equipped for such operations - which is against the law.

As far as boats are concerned keeping the area well ventilated - and above all remaining alert while filling, will see you minimise your risk.

If anyones interested I've got a great AVI movie file of a young lady in the US who found out that cashmere and fuel don't mix - a great teaching aid! PM me your email address and I'll send it to you. (Warning: it's a big file!)

[gif]

How Was a Man Engulfed
n Flames at Gas Pump?

from http://abcnews.go.com/sections/GMA/GoodMorningAmerica/GMA021216Static_fires_hunter.html


Dec. 16 — When a man was engulfed in flames at a San Antonio, Texas, gas station last month, it seemed like simply a freak accident, made more horrific by the fact that it was caught on surveillance cameraThough rare, so-called static fires such as that one are not that uncommon. At a gas station, something as simple as a spark of static electricity can start a fire that can quickly leave a person engulfed in flames, fire safety experts say.
A recent study by the Petroleum Equipment Institute found that there have been at least 130 confirmed cases of static fires. Most have occurred in the last three years.

The man in the Texas incident, 52 -year-old Bob Clewis, was filling gas cans in his truck when a spark of static electricity lit up a cloud of gasoline vapor and everything around it. The retired army sergeant was engulfed in flames.

"It's a miracle to be able to sit here today," Clewis told reporters from the hospital. Other people at the station rushed to his aid and helped to put out the fire. One man was seen taking off his shirt and beating out the flames with it.

Dead in Fireball

Though he suffered third-degree burns, Clewis has been recovering well. Others have not been as lucky.

In 1996, a 33-year-old woman was burned to death in a fireball at a Tulsa, Okla., gas station. A static spark is suspected in that incident as well. It, too, was caught on surveillance tape

Electrical engineer Steve Fowler and Jim Pharr, a fire marshal in Gaston County, N.C., have studied static fires extensively. While the fires are rare, the hazard is significant, and consumers need to pay attention when they're at the gas pumps, they said.

"They can kill themselves and the person standing next to them," Fowler said.

Fowler and Pharr set up a demonstration for Good Morning America to show how static charges can lead to a fire at the pumps. Most fires occur when a consumer goes back into their car, either to sit or to retrieve items while the gas pumps. Merely brushing aginst the car's interior can give the person a static charge, and if the first thing they touch when they return to the pump is the nozzle, there could be serious trouble

Taking your jacket off is just one of the things that can give you enough of a charge to start a fire, Fowler said.

Using a device that simulates the voltage of a typical human static spark, Pharr demonstrated how by making some simple mistakes, things can go terribly wrong.

Never Pull Nozzle Out

To avoid this scenario, experts say you should always remember to get rid of any static charge before you reach for the pump. That can be as simple as tapping the top of your car or a safety sticker on your window.

The people getting out of their cars should discharge their static, every time they go to the fuel port area.

And both experts say if a fire does start, never take the gas nozzle out of the car. Doing so is the surest way to turn a bad situation into a tragedy

"Never pull the nozzle out — never," Pharr said. "Leave."

When the nozzle is left in the car after a fire starts, the results are much less explosive.

Fowler said that the recent San Antonio fire illustrated a different static fire hazard, one that specifically involves portable gas cans.

Most stations have stickers that specifically warn consumers never to fill containers up unless they are on the ground. That's because a container — just like a person — can become statically charged. If the earth is not there to absorb the voltage, the can itself may spark.

The solution is keeping the gas container on the ground, and on its side.

Safety experts say prominent warnings at gas stations, and demonstrations are the best weapons they have to help keep your next visit to the pumps uneventful. Though the risk of fires may be low, each one that occurs is unacceptable, and easily avoided.

"Even though it's freak accident, when it happens, it's devastating," Pharr said.

[NQCairns]

Thanks Gary for all your info, I will be doing the discharge thing (tap or touch) first from now on, i know in the past I have been guilty of filling a 40l SS tank in a boot and didn't think about the fumes in that situation. My poly tank I usually fill in the 4wd on the tailgate and grudgingly place it on the ground when told - I will be a good boy from now on ;D.
From reading your last post there seems to be a case for filling fuel tanks while naked for maximum safety, safety is always a good defence in a court of law ;D ;D.

[Outsider]

Gary - some more great info - always an eye opener for most and a timely reminder coming into winter.

"Most fires occur when a consumer goes back into their car, either to sit or to retrieve items while the gas pumps. Merely brushing aginst the car's interior can give the person a static charge, and if the first thing they touch when they return to the pump is the nozzle, there could be serious trouble".

Information is the best defence!

[aido]

without getting too deep into spark gaps and
resonant cavities,
rest assured if some conditions are 'just right'
then a spark can be produced from mobile phone
transmissions.

[Dug]

That story of the Mobile phone and petrol station is an urban Myth but you can never be to careful. You don't get a second chance I would not like to be standing on a poly craft in a fuel fire :(

[snapperhead]

Hey NQcairns I'd be getting your RCD and fuses checked if they didn't trip one of them should have worked regardless.

[Outsider]

If the "just right" conditions include the mobile phone in question coming equiped with the optional flame thrower attachment...

[klyons]

I saw a report several months ago basiclly saying there has not been a single explosion/fire anywhere in the world directly involving a mobile phone. As said earlier, explosions while refueling occur because of static discharge between the person filling,nozzel,fuel tank.
Consider this- if a tiny spark in your mobile phone can cause an explosion how about the ignition leads on the car pulling in behind/beside you?(take a look under the bonnet with the engine running in your garage with the lights out and you will know what I mean).


Kev

[aido]

If the "just right" conditions include the mobile phone in question coming equiped with the optional flame thrower attachment...

;D ;D ;D ;D ;D ;D
the old flame thrower attachments should never be used during fuelling,
however some credible sources do have concerns for 'basic model' mobile phone use while fuelling,

http://www.casa.gov.au/rules/miscinst/2002/501_02inst.htm

http://www.centralian.nt.edu.au/misc/safety_alert.htm

and from the phone manufacturers, no problemo...

http://www.amta.org.au/?Page=180

[aido]

???

[NQCairns]

Snapperhead wrote:Hey NQcairns I'd be getting your RCD and fuses checked if they didn't trip one of them should have worked regardless.

Yeah 2 months ago I know the earth leakage doovey worked cause i am still here reading Ausfish, this time I am glad I treated the live cable as suspect. After very carefully picking my way around that black snake and switching off at the outlet I went straight to the fuse box to reset stuff but none was needed. Soon I will bring up the subject with a family member who is an electrician for some idea why, I have no real good idea atm but I get that alot lately ::). It tested good. cheers.nq

[Outsider]

Aido - thanx for proving my point.

No phones on planes - messes with their electronics.

Phones that light up etc - greater drawer on the battery creating sparks between battery and handset.

Negligable risk from phones on forecourts - because it's the energy transfer inside the phone - not the radiation that every phone emits or receives - otherwise fuel sites all over the world would burn to the ground daily due to people who insist on using phones at the pumps.

I also have footage (unfortunately not on PC) of the incident in Melbourne of the guy who had the phone in his jeans pocket (switched OFF) while filling and in that case it was the movement of the battery on the phone handset that created the spark which ignited vapour.

[phewy]

come accross this pic
http://www.safetycenter.navy.mil/photo/images/photo57_1.jpg

and this article about mobiles and fuel stations
http://www.safetycenter.navy.mil/articles/cellphone.htm

[aido]

yeah, i tend to agree.
the chances of a problem occurring might be a gazillion to one.
i've been known to fuel the lawnmower with a ciggy hanging out
of my mouth, why should i care about a mobile phone fuelling risk.

cheers, aido.

[Fordo]

The other potential for mobile phones to be a problem during refueling is the charge in the battery.

If the phone is dropped and the battery seperates, the potential for a spark is present. As fuel vapours are heavier than air. Kappow!!