Shocking Cars: Newsletter Challenge (04/17/07)

Let me blunder in . The toll booth collector didn't get zapped (?) . Anybody know if something changed in tyre manufacture in the 90s ?

The '90` s...................

Two possibilitys come to mind:

* There was a vogue for 'Undercoating` in that period. If such was
applied it might interfere with the function of the static drain wiskers
installed at most toll booths and drive throughs.

* That era saw the early Capacative Discharge ignition systems.
The secondary coil might be inadequately frame-grounded.

Maybe the collector wasnt a person, but one of those funnels you put your money into........and you touched it as you put your money in. Hence no mention of the collector getting zapped

Toll booth collectors are trained to be resistant to all forms of discharge.

With the reduction of carbon black powder in tire manufacturing, and the addition of silica powder, the tires had less "rolling resistance", but didn't discharge the built-up static electricity as fast as the previous tires. As you drive, static is built up, much like a balloon rubbed on your hair. Silica is a lousy conductor, so the drain-off was much slower. This all started around 1985-86.

On second thoughts , your 1990's car has nice retro synthetic seat covers so you are driving along charging yourself up to several KV. Not much charge had accumulated before your snack stop.

I wonder if it's not so much the seat "covers" as it is the frame within the seat acting with the cover to produce a shock.

I notice that whenever I lift a bed mattress (especially the small crib mattresses) to either move them from room to room (across the carpet) or when changing linens (especially flanel) I generally get a jolt.

sort of like chewing on gum wrappers if you have metal fillings ....... if you're old enough to have metal fillings in your teeth and haven't tried chewing on foil you're in for and electrifying and memorable experience......

I've experienced the same "jolting" when moving a mattress as well.

And I've also stupidly chewed foil with metal fillings (had a phase in life during my youth when I tries to disprove some of the bigger urban myths , like putting your tongue on a frozen light pole .... been there, done that as well, very stupid....)

So my question to the group is ...... why the jolt from the mattress moving ?????and why the agony from the foil chewing ?????????

Rub a balloon with various materials and you can 'stick' it to the wall with electrostatic charge . The mattress situation is essentially the same.

Mercury amalgam fillings + tinfoil = battery. Dip a battery in acid and watch the bubble spewing from the contacts (I'd stick to a 9v domestic use battery and vinegar ) or touch it to your tongue. I'm wincing as I think about tin-foil.

thanks Kris....

It is nice to have access to genius on a world wide perspective.

question now is, should I be concerned about Mercury Amalgam from a "mad hatter" point of view ???

It's too late to ask me , but then I wouldn't recommend asking a dentist either.Don't compound the problem by dragging a mattress with your teeth is all I can advise.

KRIS-While we are on the subject of ESD-of all of the fatal fires at gas stations, women are the majority of the victims! The answer puzzled researchers for a while but they finally came up with the answer. Men, it seems, get out of the vehicle, start pumping the gas, while in the vicinity of the pump nozzle. Women, on the other hand, start pumping the gas, AND GET BACK IN THEIR VEHICLE! This action permits ESD to build back up by the simple action of sliding over the seat again! I read that fact in a service station magazine. James

You have a point - how often do you see a woman preening her hair in a gas station while the car fills up (or even while driving ) - all that static ! Now I'm in trouble

I have been unable to find a single case of fire at a filling(gas) station due to static by an incoming car (proven that is). The possibility exists , but I wonder if that logic is why UK hospitals prohibit mobile phones ("they interfere with sensitive medical equipment"). Odd , because med staff must have some special type of mobile phone . It may just have something to do with the National Health Service here being bust and quasi-run by private companies who rake money off with pay-phones that charge several times the going rate. Couldn't possibly be the same organization that sent a bunch of efficiency experts on a junket to a posh hotel (with partners included , and world class golf-course included) .Those experts who didn't turn up on two occasions and had ( well us)to pay a full forfeit fee. Of course not. Me ,cynic ? never ! Phew , sorry James but I have to vent steam somewhere.

Back to the op there is certainly a good point to be made in the original question. It's just strange that those who should have a big interest have never made a definitive statement on the issue.People like major oil co.s don't exactly have a track record for promoting the general public interest.

Your suggestion of women sliding about on seats more than men will send me off to sleep a lot better than some thoughts I had in mind !

Kris, where in the UK have you found filler nozzles with lock pins that work? These were made illegal here years ago! The "ladies" you see preening must be doing it before or after filling up (or passengers?). Oh and in answer to your question - never - I've never seen (or done) it.

As to the mobile phones in hospitals, the NHS are (very quietly and only if pressed) admitting that they're not as dangerous as first thought and can be used. Incidently, my mum believes that if she puts her phone on silent whilst in a hospital, then this stops it affecting any equipment. It wasn't worth the agro to disabuse her of this one! Solution to NHS problem: sack the managers and bring back matron! And the cleaners.

"Solution to NHS problem: sack the managers and bring back matron! And the cleaners." Je dirai meme plus

Thomson

I might be cynical git here, but I think the NHS ban mobile phone because they charge so much to use the pay phones they have. Whenever I go to my local hospital, I see all the doctors and consultants using theirs in the corridors. Oh, and the excuse given not to use them in petrol filling stations doesn't stand up, think of the sparking potential when your starter solenoid kicks in. The real reason is that mobile phones can effect the pump readout. I have this on very good authority. As to bringing back Matron's, it's got to be Josephine Edwina Jacques, the best matron ever. (And a qualified welder!)

Breaking news this morning folks, new rules are coming into force after the NHS acknowledge that mobile phone do not interfere with equipment (at least the usual stuff -an MRI scan would be interesting ). Af air number of hospitals already allow them . Personally I would hate them if stuck on a ward - It's bad enough on a train. Perhaps it will force a lower pay-phone tariff .

Now you have let me in on something ER , I shall invest in some hair - pins .

This is a completely irrelevant posting (what do you mean 'most are' !), as I just noticed your metamorphosis and had to check . For some reason I had the colours of the roses confused. Lots of nice downloads on google "............. rose picture" . I like the current one you have , but the stylized ones are nice with all the hidden maths (Fibonacci ......). Still , ...a rose by any other name...

Have you had a laugh yet at all the " stating the bleedin' obvious " posts since the answer was given here. Weird , must be a time warp.

Isn't google wonderful?!

And you found the one I was looking for - the Alexander Rose, my school emblem. Hmm...that gives me an idea.

I hadn't noticed the answer was up....glad to see we were all right LOL

Funny...you were too busy having a conversation with Kris to notice that the answer was posted and I was too busy reading said conversation to notice the same....

...I was too busy writing the next instalment of An Engineer in Paradise to notice that blah..blah!

I think you will be a best-seller with your new project ER . It beats the !!!! out Harry Potter - J K Rowling will be livid she missed this potential series . Mark me down as a subscriber .

So you reckon it would be worth requesting my own blog space for the "book"?

I would be an avid reader.

Aphid readers? Do we need ladybirds to protect the rose?

Fly away home....

and some of these perhaps....as long as they only eat the aphids & wasps!

Can you provide a source - my copy has mostly less archaic spelling, but finishes "upon a brere".

Pedant III

I'm sure I posted a reply to this last week....must have hit something wrong.

Quote is my old school motto. I had to leg it down to the main hall to check the spelling on the window each year as I could never remember it. I thought there was a grave accent too. I'll need to find an OG mag...it was on a cover once. (Hmm, must renew subs!)

Are you an OG too? Log in and PM me!

Heavens! I assumed you knew the source. It starts verse XXVI of "Amoretti", a set of poems ca 1593 by Edmund Spenser. (Surely the motto would appear on your school web-site. It's rather too recent for my school...)

I checked over the weekend, and with all the modernisation, I couldn't even find the Rose let alone the motto on the web-site!

As to the source, thank you...I guess that's one of the other things they assumed we'd know by virtue of being there...like not going through the front door of the main building (I was caught on my third day there...it was the first time I'd been to the building). The headmistress in my time was a classicist, so I guess dear Spenser was a little too modern for her

Off to look it up...

my bad....

No probs...

OMG - my ears twitched , so I had to see what was happening. Good old google - I knew you old gals were up to something !

Google led me there , so I know it's true.

I can see another Dan Brown novel on the way...............

Now you're scaring me .

<sulk> My writing style is much better than Mr Brown's.

What a boring, an inaccurate book. I read it inside a 24 hour period.

I think I read it just as quickly, I think the phrase is 'dumbed down'.

In the rest of the 24 hour period in question, I flew to Paris (leaving UK on a 0630 flight, did a day's work (well, a French day's work!) at a bus depot in Paris, found my hotel and ate out in a restuarant on the other side of Paris (alone ).

Luckily, the book was the softback version and I was allowed to take it in my hand luggage!

Full marks all round for perseverance. The thing's unreadable.

Fyz

Fear not , some of us still have taste.

The authors of a supposedly factual book sue the author of a fictional book (that pretends to be fact) for copying plagiarized inventions in their own work . You couldn't make it up. Stick to Engineering romance a la M&B. Inspiration may be found in the current challenge question - a bunch of (largely) men arguing over who gets a Goat . I have already chanced 1 sheep joke , progressing to Goats may be pushing it (though they do have lovely eyes )

How come you were inside for 24 Hrs ?

Oops , I see. Not 'inside'. So you did background research on the book as well.

Hang on a min , I've been dangerously close here already with an earlier posting. Yikes ! Sorry , sorry , please no .

I have an additional concern going - you mentioned a connection with Roses --- Cadbury's----Blink-----current question. Have I unearthed a quaker conspiracy ? Me , paranoid ?

Never fear, Kris, I am working on episode 3 - it won't be in the challenge question, as I now have a Blog for the purpose!!! And the goats are definately making an appearance....

I appear to have missed the point of your apology. Please explain (I shall have to punish you anyway)

Have you only just noticed the Quaker Link? You missed Rowntree's...he of the Commission and Report on poverty. Incidently Elizabeth Fry made and donated beautiful vestments and altar frontals for a certain Bristolian church (the fairest and godliest in all England), which is odd for a Quaker.

Oh, and don't forget the oats!

You did it ! Ace . I will have to have a good look later , I am far too busy having fun with Yuval. Goats will have my attention in due course.

You have probably by now seen my motives re apology - I have a long running game with Yuval.

It's preety amazing , all the things that Quakers have achieved. I have to confess that porridge has never really done it for me. My current fix is Kellogs Fruit 'n' Fibre - I love trying to cheat the box and get more than my fair shair of the tasty bits which try to settle out. Oddly enough I was going to start seeking the anti settlement strategy employed by Kellogs ! Oats pure and simple is currently logged in the back of my head with Goats for future annoyance/amusement.

Kris,

As a women that does not preen while filling up, it does irritate me to see other women doing this. Note that in the states, we have 2 reasons for not immediately filling up when driving up to the pumps. 1 - Pay before you pump: As hard as it is to believe, many people still use cash for gas purchases and have to go into the station to pay before they pump. 2 - Lock-on pumps: Even though I stay outside while pumping, even in the coldest of weather (often below 0 degrees F, -17 degrees C in winter) I do not like using pumps that do not lock on. Both of these common occurrences are opportunity for static to build and cause an ESD situation.

Also, hospitals banned the use of cell phones because of the RF interference causing issues with electric and electronic equipment. Connie Chung, in the day she was a respected news person, did a story in the early 90's about out of control electric wheel chairs resulting from cell phone use. It is a video that had been used in a class I tool on Electromagnetic Compatibility (EMC). There had been reports of people actually loosing control of their wheel chairs and being literally driven off the road and over drop-offs on the side of the road. Cell phones being used in the area were found to be the cause. In the video, simply holding a cell phone near an un-manned electric wheel chair could cause the chair to move forward, back and in circles uncontrollably.

Cell phone design has since changed and testing of both cell phones and medical equipment for EMC compliance has changed. In the states, not only will you find the "Cell phone use prohibited" signs missing on hospital entrances, you will find doctors and nurses using cell phones as a tool to perform their jobs.

Toni from Milwaukee, WI

Hi Toni , interesting to hear how things work elsewhere . Over here paying after you get the gas is the norm - often exploited by those who find themselves cashless and low on fuel.

I hadn't heard about the out of control wheelchairs . Our National Health Service is in the process of doing a U-turn on mobile phone policy . Many were annoyed because the available pay-phones were set to a high tariff , and like you say med staff would walk around using them anyway.

Kris

Connie Chung, in the day she was a respected news person, did a story in the early 90's about out of control electric wheel chairs resulting from cell phone use.

It's the prospective effect of phones on implanted pacemaker devices that is particularly disturbing.

A site to search for petrol fires due to static: http://www.pei.org/static/fire_reports.htm

No fires have been found to have started from phone use.

Is it just me? I read the first four "accounts" (description of events) and all drivers were women (?) who sat back in the car while refuelling. Although I doubt that the gender has to do with the problem, the returning-to-the-car seems to be a definite trend, no?

Why would people return to sit in the car? (Kids in car, adjust make-up...)?
Nylon stockings rubbing anything are just great for generating static - and stopping the discharge*.

Men sweat, women glow (and yes, there is a physiological basis for this).

Might this just suggest some gender-specific trends. What surprised me was that not all of them are culturally based.

*Some synthetic overalls do that job nearly as well - but you probably wouldn't want to hop into and out-of your vehicle if you were wearing them.

Why would people return to sit in the car?

people return to sit in their cars during the coldest (and dryest) days of winter, when they are wearing flanel or wool (good insulators for warmth and good conductors for static electricity).

in some areas of Minnesota it's not uncommon for -40° to -50° F wind chills.

Shame the proper explanation looks so d.... rational. There's nothing about the locations in the reports - but the majority of the ignitions seem to be in wintertime, so it looks as if you're right. (Unless reason for the lack of reports in hot dry weather that there's more vapor, so there's no-one left to report the detail)

why?

i can think of a few reasons.

1), handicap. My husband spent a few months recuperating from foot surgery. According to him, standing was pretty excruciating.

2)organization: I often go thru my laptop/papers bag whilst getting gas, on my way to work, conference, talk, etc.

3) as a parent, I would hope ANY gender parent of a small child would stay in the car. when our kids were little, we'd just roll down the window & hand them the card or cash.

Oh wait- we live in Oregon. They don't let us pump our own gas here. The reason given has always been "creates jobs", not "prevents electrostatic-caused fires due to charged(+/-) customers". That, I've never heard of before.

in fact I always have to remind myself to get out of the car when i travel for work or pleasure. I've been in OR for 20+ years now, and have definitely gotten out of the gas-pumping habit!

regards,

kw

It's NOT the customers who cause the static, but the interaction between the pump nozzle and the plastic of the filler tube. There was not a static problem until metal tubes were abandoned (probably due to sparking when two metals collided).

Now the plastic is coated with anti-static paint, but that is prone to damage.....

<>it would be foolish to return to sitting in a confined space while transferring gasoline from<>a pumping station into the vehicle, stay out of the car and take children out also, it only takes a minor fault to cause an inferno, gasoline is dangerous stuff

Those are interesting stats - 169 incidents throughout the USA in 15 years. Compare that to how times a petrol pump was used in the same period and geographic range. Has anyone got any idea how high that figure could be? This is not going to be very high on the hierarchy of control for any health and safety manager.

H&S is not just about likelihood of an event, but also the severity of "damage" possible - imagine the result if the whole gas station went up!

These possible incidents will not just have an impact on the gas station, but also severe repercussions for the manufacturer of whichever device or component was responsible for the incident.

Did you look at the link I gave to the info about the Mini recall due to paint coming off the fuel filler assembly, causing static build-up?

http://www.esdjournal.com/archives/press_releases/2001/bmw/mini.htm

I think that manufacturing processes are getting to the stage of being too lean when a coat of paint is used to provide electrical safety - its much too easily damaged, and too thin to survive even a scratch.

What you say is all to true, but given the high standards that filling stations have to coply to, the chances are very remote........even with the idiot factor. As to the paint, I don't think paint is anti static anyway.

The paint is not anti-static, but conductive, allowing any static charge a route to ground.

The flashing of fuel vapours only stops when the supply of oxygen is used up, so it is possible for the fuel tank to explode where only a few litres of gas are pumped into a nearly empty tank. (I always fill my tank to the top when refuelling just to make sure!)

I have to say, I always fill right up as well. I think the point I want to make is that the hazard may be high, but the risk is low. If the risk was high, we would see explosions out the window every day!

The risk is only low because of the safety procedures now in place - increasing these is not viable (financially, at least) but the car manufacturers need to maintain those safety aspects, not cut corners to produce vehicles which may at some point become unsafe - any change in the make-up of fuel (eg bio-products) may have a detrimental effect on the paint - petrol is already a pretty good paint stripper if abused in the right way.

Metal fittings wearing out caused inconvenience before injury - who cares about a bit of paint coming loose, so long as it is hidden by the cover (except those who have read this thread)?

Dissipative (so-called antistatic) paints, varnishes and even polishes do exist. They were (are?) used in semiconductor assembly facilities.

"question now is, should I be concerned about Mercury Amalgam from a "mad hatter" point of view ???"

Only IF your 'Tin Foil Hats' aren't genuine and some one substituted cheap household kitchen foil for the real thing!

Not unless you are in the habit of chewing foil.

To be serious, there was some discussion of mercury 'doseing` from amalgam
fillings. The consensus was leave em until they need replacement.

KRIS is right! Sounds like a charge buildup by your pants! Better have a fire extinuisher ready when you gas up! James (darn it-I need spell checker!) SORRY!

Just noticed , I meant to say the charge of static only got to a fun level when you'd done the long stretch of driving to the drive-thru. Hands up anyone who hasn't driven miles just to get a burger one late night (and if you haven't , then you haven't lived ) . I was in haste James , just had to beat Davo to it . He's gone off-line , either in despair or going to KFC at Alice Springs (sorry Davo , couldn't resist ) to find out what I'm obviously missing. I'm sure the truth will out here.This ones a bit unfair on non-American cultures (toll-booth , drive-thru ....). Interestingly it was the 90's when gas-station flambes hit the news.Mobile phones are not allowed in UK filling station (but that is another , very long story )

If it came from Michigan the floor boards are rusted out and you feet are dragging.

I know that feeling-I am from Pennsylvania. James

Wouldn't the buggy be 'rotted' rather than 'rusted' though ?

Kris-Here on this "side of the pond" we say "rusted " when referring to metal and "rotting" when referring to an organic material such as wood. In reference to "floor boards" the floor of the model "T" by Henry Ford (Ford Motor Co) were made , in fact, from shipping crates from parts! James

Same usage here James . It was a lame suggestion that you may be Penn. Amish and hence drive a wooden buggy (though on reflection there's no reason said buggy should have wooden flooring ). Henry Ford has to be up there with the 'Greats' for his use of mass production . I bet credit for production lines is more hotly debated than who built the first computer etc. I was reading recently that the Chinese Terracotta army , whilst appearing individual , were actually produced by assembling from a limited range of styles within body part categories (eg legs type 1/2/3,arms type 123 etc ). If true , they certainly had the jump on more modern component assemblies (large range of Barby dolls from multiple component choice)

KRIS-OK, sorry about that! I was raised up around the Amish. Good people. Some strange customs though. If The price for gas keeps going up, those horse carriages are starting to look good! James

No problem James . I have a real admiration for some Amish ways (and many others around the world who live a 'basic' type lifestyle ) . The life-style should make anybody question the purpose of 'existing' and what a fulfilled life means. It's not for me , but hats off to them all the same. I know a guy who rides horseback around town (believe me it looks odd in the UK ) , but he gets there quicker and less stressed than anybody else. Kris

In the '60s, I worked in a converted 'stately home'. One of my colleagues expressed regret that 'no-one these days rode their chargers* up and down the staircase. Another rose to the challenge - on his Triumph motor cycle.
(A motorbike might be even quicker than a horse across town, but it certainly looked tricky on a staircase.)

Fyz

*=horses - in case this terminology doesn't travel

I just couldn't help adding to your comment about the floorboards of the model "T", they were made of the shipping crates for the windshields and were specially designed by Henry Ford to be the exact size for the floorboards.

I've got no such shame with an interesting idea ; Henry Ford was using the packing materials to make the finished product , and it's only now that we're waking up to the waste of packing materials for our 21st century goods. He was way ahead - Commercial success = environmental success. How much garbage are we all forced to buy in the supermarket . Maybe we should be able to take all that packaging back to the shop and force market economics to lead the way.

Concept has been tested - you are allowed to "unpackage" your shopping at the till and the supermarker are obliged to dispose of the wate. There's a UK campaign to encourage people to do this and so "encourage" the supermarket to get suppliers to reduce packaging.

I bought a 24 pack of cat food the other week; there wasn't room in my panniers for the box, so I opened it & packed the pouches around my other shopping. Box left at the till - job done. I keep meaning to take the outer wrapping from multipacks of cereal bars etc, but am usually too busy packing to remember

So you are the person who does this ! I thought it may be Hugh Fernley Eatsitall .

24 pack of cat food ? No no. get liver from the butchers - they love it (the cats that is ,so do I ) and you only have to mince in a few extras. The dog spits out the veg (which is surprising since mine is otherwise stupid)

Does the 'un-package at the till' thing work for baked beans ? . I'd be up for going there with a plastic container , but I don't think 'johnny - spotty face - new on the job - minimum wage - teenager' wants to be dumped in that position.Best option - don't use the supermarket ,not never.We will all pay in the end. And mind the bike , when Johny's had enough of being exploited he''ll ride off on it without a second glance - nobody helped him so why not. Ooh -err , I'm sure Tesco have a good point somewhere. If you use independent local retailer , please excuse all previous rant ER .

Rust worm! We have a saying to, on a quite night, you can hear a ford rusting.

If it's a dilapidated ford with fluffy - dice etc , that noise is not rusting .

Every time it rains, a bit more of my Mk11 Escort runs down the drain.

That's an easy one.

The tires are the problem. The tires lack the carbon content that bleeds off static electricity buildup generated when the car is rolling.

Welcome back AH - haven't seen you in ages.

Then the solution is one of those amusingly lightning shaped anti-static trailing thingies that were so popular in the 80s & 90s.

Hang on - wouldn't the tyres be modern tyres - or is it modern tyres that have low carbon content? Do modern (post 90s) cars have other methods of dealing with static build up that means the lack of carbon is irrelevant? In my experience, the static build up is random - short journeys, long journeys, loads on one day and then none for months.

I'm more inclined to go with the nylon seats and carpets idea...

Is this question a reflection of engineers' salaries...we can ony afford a car more than 17 years old?!

..those amusingly lightning shaped anti-static ..

I'm sure they were marketed to stop the kids throwing up on you in the car (now replaced by bracelets that press on an acupuncture point). Doctors give a good insight to this proposition - When the validity of routine Tonsillectomy was questioned , all the ENT specialist suddenly 'discovered' the huge problem of 'glue-ear'. As they say down under -that'd be right.

It's definitely down to rustling fabrics , though some suggest that air molecules battering the car is the cause. There may be room for arguing the direction of the shock and who/what has a positive/negative charge , but not much more. On a similar vein , has anybody noticed that they don't get shocked by using a supermarket shopping trolley anymore (people wearing flares can always post anonymously ) ?

I'm still here, just busy. ;-)

Actually, the old tires were better. The newer tires, in a bid to reduce rolling resistance and thus improve gas mileage, use less carbon black in the tire compound. Tires act like large Van deGraff generators when they roll on the road and build up static electricity. With the high mileage, low resistance, tires the energy can not bleed off as fast as it is generated.

This phenomenon is worse in the winter when humidity is low. It is also a problem when fueling your car. Winter poses a risk of ignition when you fuel up your car and static discharges causes a small spark. That is another reason that it is good to fill up the lawn mower gas can on the ground. I understand that there have been documented cases where fires have resulted when a spark ignites the gas vapors while fueling.

High performance tires that are designed to maximize grip on the street use more carbon and they also scrub their rubber off faster. My performance tires only last about 8-10K miles with normal driving (no competition driving). I never get static buildup with any car with those tires.

There are two solutions that you can try; 1) buy a grounding strap that drags under the car, or, 2) buy tires that have a higher content of carbon.

On a side note, aircraft in flight have a huge static electricity buildup problem while in flight. Look on the trailing edge of the wings next time you fly. The metal spikes that poke out along the trailing edge of the wings act as discharge points for static since the tires do not touch the ground during flight.

Hi Hero

"The old tires were better". Are you saying that this car was an exception, because the specified tyres must have had a low rolling resistance and therefore less carbon?

Following the trend of the question in this respect: would more recent car (or tyre) designs include something to reduce the problem in spite of their tyres' relatively low overall carbon content?

Apologies that I'm probably being exceptionally dense here.

Thanks for your tolerance

Fyz

Well, it is highly likely that the tires have been replaced since the car was new, so it is not far fetched (or is that it near fetched?) to have a new set of tires on a car that goes up for sale.

You can buy all kinds of tires. They run the spectrum of performance and cost based on tread design and tire compounds. So in this instance it is likely that a new set of tires were fitted with a very low carbon compound. Furthermore, low humidity amplifies the problem.

I can only guess that manufactures deal with the problem of static in multiple ways and some deal with it better than others. Probably cost is one (if not the main) issue, but I do know that lower rolling resistance tires have a lower carbon content.

some body

on the early 90 they starting using the RADIAL TIRES those tires had large amount of steal wire and a poor insulation it probabbly build up static

Hi! I'm here, just busy!

Actually, the old tires were better. The newer tires, in a bid to reduce rolling resistance and thus improve gas mileage, use less carbon black in the tire compound. Tires act like large Van deGraff generators when they roll on the road and build up static electricity. With the high mileage, low resistance, tires the energy can not bleed off as fast as it is generated.

This phenomenon is worse in the winter when humidity is low. It is also a problem when fueling your car. Winter poses a risk of ignition when you fuel up your car and static discharges causes a small spark. That is another reason that it is good to fill up the lawn mower gas can on the ground. I understand that there have been documented cases where fires have resulted when a spark ignites the gas vapors while fueling.

High performance tires that are designed to maximize grip on the street use more carbon and they also scrub their rubber off faster. My performance tires only last about 8-10K miles with normal driving (no competition driving). I never get static buildup with any car with those tires.

There are two solutions that you can try; 1) buy a grounding strap that drags under the car, or, 2) buy tires that have a higher content of carbon.

On a side note, aircraft in flight have a huge static electricity buildup problem while in flight. Look on the trailing edge of the wings next time you fly. The metal spikes that poke out along the trailing edge of the wings act as discharge points for static since the tires do not touch the ground during flight.

only 7yrs 4mos since the 90s.

well i remember those trailing straps, each decade brought new sales pitches, however static electricity is a horrible nuiscance to industrial scenarios. I remember that early 80's to 90's pass. cars had 'mysterious' electronics failures...a real headache for mechanics...these problems had no probable cause, arbitrary it seemed.' Now, due to computers, many know that static electricity can obliterate chips, and even large transistors, coils & etc.

i think [not know details] that the auto industry has engineered some anti static features into their designs, to reduce callbacks...

Anyway, grounding devices are required in most ind. veh & machy. apps.

back to orig. idea...

Firstly, if it were car dependant, it would happen almost equally to everyone...

Of course Dry conditions are prerequisite, The next major factor is the skin cond/chemistry to support a charge, then almost any friction incl dry air. can build a charge. When i am not fully hydrated, but not sweating.. everthing shocks me, esp my late mod car. Thats entirely due to my skin cond...weather permitting.

there are always certain people in the office who should stay outta the server vault...or whatever, they are natural static accumulators, gaining charges when no one else is...they unwittingly slay every machine they touch.. surely you know at least one of those LoL (my Girlfriend is one)

Some customers i had when i was a mechanic were like that.. somehow all their machines went nuts or rebelious, sometimes immediately upon getting into the car.then when i drive it & by myself the they purr.. hmm

Tip, wash hands before starting at the computer, it will live an easier life...maybe you too

& always stay in electrical contact with the gas nozzle & car...if you think the place is static prone or you know you are.

Static of enough voltage to do damage might not be detected even tho carried and passed thru skin etc... its the voltage which penetrates, very little current needed. the penetration is the damage...

when a spark travels over dirt & moisture on a Coil tower, or dist. cap, 2 sparks in the same path across the plastic/bakelite is all it takes to create a carbonised electron hiway..[shortcircuit] more sparks, bigger hiway..

my coils & caps last forever because i won't let them get dirty...

j bo

hero....wouldn't those 17 year old tires be dry rotted and probably not on the car now, but likely replaced by "new" ones?

Yes! that was my point and the newer tires on that car were probably selected for their low rolling resistance to improve gas mileage. Everyone feels the pinch, so selecting a lower resistance tire seems like a good probability.

The low rolling resistance tires have less carbon black and will build up static at a higher rate than more conventional tires. Those tires also have a harder rubber compound and last longer. The trade off is that they do not stick to the road as well as a high performance tire with a softer rubber compound, which contains more carbon black.

So, I am betting that the tires are the problem and that is due to the lower carbon black content.

This is correct. In a (successful) attempt to improve gas mileage via reducted rolling resistance, tire compounders replaced (conductive) carbon black with fumed silica (non-conductive) in tire compounds in the 1990s. As a result of this change, the *electrical* resistance between the car and the road was increased while the *mechanical* resistance (drag) was reduced. This allowed static charge to build up on the car (from driving and the impingement of charged dust particles). That charge was eliminated when the convenient path to ground (through the toll operator) was provided (ouch!).

Subsequent improvements tire compounding have maintained the reduction in *mechanical* resistance, while reducing (again) the *electrical* resistance.

Also, with the advent of EZ-Pass (and similiar non-contact) technologies, the discharge through physical contact with the toll booth/operator is less likely to occur.

OK ... what do I win ?!?!

Maybe it's time to buy a new set of spark plug wires for that old car. Leakage from them to the frame until a discharge path to any lower potential is established.

I deal with this problem on a daily basis in trying to maintain an "ESD Class 0" production floor. My guess is voltage generated from clothing rubbing against the vinyl seat covering. A path to ground is created when touching any grounded surface outside the vehicle.

Hi jowens . I agree , but the question is not 'fair' to those unfamiliar with the set up of toll booths and drive throughs - the 'answer' will probably explain a discharge mechanism that depends on a familiarity of these (is the drive through assistant running around in artificial fabrics etc) . Is there a brief summary of how you try to keep an ESD 0 environment and what kind of place is it - electronics, petrochems. I understand even flour mills have an explosion problem (all those combustible particles with a huge surface area ) ? Kris

Kris,

Flour mills, paper mills, anywhere which has large scale dust extraction/collection - all these are subject to assessment under the ATEX Directive (94/9/EC). One of the big hazards is the static build up in the dust "cloud". The discharge spark, as you hinted, is capable of igniting the cloud, with devastating results.

One of my responsibilities is looking after the ATEX rating on our spark arrestors - although these are designed for diesel engine exhausts rather than dust machinery. You pick up the other info on the legislative training sessions. There also a close link between ATEX approvals and DSEAR regs - like : don't point the explosion panel from your pressure vessel at a brick wall! It's been done.

Jowens: are you in electronics? We've had some fun dealing with the ESD resistance of an ECU we buy in...I'm not allowed to brush my hair before touching it!

Oop north , you probably know about coal mines (well used to anyway ) . Methane can go off , but it's mainly a problem because it acts as an ignition source for the coal dust (which is when you really have a problem ) . One 'after the event' solution is planks carrying stone-dust hung from the roof. The air shock wave sends it all up in the air and minimizes the effect and extent of explosion. Big bang, small roadway , nasty result.Loads of intrinsically safe electrics can never escape from the fact that static is almost impossible to eliminate . Electricity is generally seen as a 'silent killer' but static is far more insidious.

hi kris...surprised the toll booth operator is shocked as there usually is a discharge wire sticking up from the ground that contacts the car when entering....unless the driver is too insulated. agree that ESD is tough to control in a insulator / insulator environment such as clothes and car seats....maybe its the materials used today versus in the 90's for the seats and interior surfaces....no more metal anywhere inside to provide a contact discharge path for the driver or occupants....

OK, let me add some information for you. I get the shock when ever I step out of my 2003 Chevy pick-up, I don't get a shock when I step out of my '97 Trans Am, and I don't get a shock when I step out of my wife's 2007 Maxima? When I rent a car, I seem to get a Ford Touris, and I get a shock when I step out of them. What gives?

More information. When I stop the car, (or truck) everthing is OK, I can work the ATM or order a burger form the drive up window, but when I step out, I'm on the ground, when I reach for the door to close it, ZAP! it hits me in the hand.

Why? More improtant... what can I do to stop it, it's getting old. (Foot note, my wife does not get ZAP'ed... )

I hate to say it mate , but you might be sweaty ! Different people have different levels of conductivity. Your wife sound like a cool character who is safer from shocking because she has lower conductivity ( it's the basis of a polygraph test ).

I can't figure the ATM bit , though it would be possible to use one without grounding yourself and getting zapped. Touch the car body before you get out (or better still as you drive along ). BTW ignore chat elsewhere of fireboxes and let me know if you need more links. Kris