Comments on: Episode 20: Exploding Jawbreaker

By: jay

jay — Tue, 11 May 2010 20:03:23 +0000

I was just sandblasting some fiberglass (Acculam) panels that will be used in the aerospace industry and these puppies can really build up a static charge. The panels are 2′x3′ & .035″ thick and can create a spark over 2.5″ long, I was hit by one of these and it made my whole body jolt, from my head to my toes. I was a little numb and tingly for about 5 minutes afterward and while I don’t know if this was enough to kill a person, it was not a pleasant experience….. While it’s not PVC pipe, it is a composite.

By: Steve

Steve — Sun, 04 Oct 2009 06:13:13 +0000

I worked at the Syncrotron particle accelerator at the University of Wisconsin. In 1988 a co-worker was shocked and rendered unconscious by a discharge caused by sandblasting the inside of a long section of PVC pipe. The crucial element that was missing from the test on the show is that my co-worker was sandblasting the *interior* of the pipe. From a physics perspective it is easy to see why this is different: trying to apply charge to the outside surface is self-limiting– the more charge builds up, the more repulsion there is. This is not true of interior surfaces– a uniformly charged cylinder has no electric field anywhere in the interior of the cylinder. This allows charges to be brought to the interior wall and transferred irrespective of how much charge is already there. This is the same principle by which the Van de Graaf generator works. While PVC is an innsulator and thus there is no explicit guarantee that the charge will be uniformly distributed, the sandblasting grit would act as the conductor. If charge began to concentrate in one place, the resulting electric field would cause an increase in the rate of charge deposition opposite the excess charge region.

By: Zephraim Dotson

Zephraim Dotson — Fri, 20 Feb 2009 06:02:03 +0000

have any of you heard about the buddist monks who can shatter steel with a single punch or kick? They had a documentary of it on the discovery channel or some other station. not exactly sure. I think Adam and Jamie should check it out, what do you people think?

By: shotblaster

shotblaster — Fri, 20 Jun 2008 05:22:49 +0000

I worked as a shotblaster for 3 years and a few times encountered pvc and can say that this myth may well be plausable.The working conditions involved an extractor so the environment stayed clear of dust, also the type of abrasive may be key to a succesful shock although not sure this is just the setup I worked in.I generally used aluminium oxide a larger grit is better to keep dust levels down.I personally have felt a very large shock the bolt was about an inch thick and made a very loud clap although it wasnt a tube i was blasting but a sheet it obviously didnt kill me but i would think that if the piece of pvc was a lot larger it may well do so.

By: Me Three

Me Three — Mon, 09 Jun 2008 17:43:00 +0000

PVC pipe plus pulp fiber equals wicked static charge. At my old job, several people complained of shocks while cleaning pulp fibers out of a steam heat exchanger coils when vacuuming with PVC pipe wands.

By: Hyler

Hyler — Mon, 04 Feb 2008 04:44:01 +0000

You can build up a very large static charge on PVC pipe by useing it to place blown in paper fiber insulation. I had the experience of having a blinding flash and a loud report while doing this work in my attic. Fortunatly the charge went into a grounded electric box. If you have ever done this work you may have experienced feeling the hair on your arm stand up as chuncks of matterial pass through the rubber hose.

By: Travis

Travis — Tue, 22 Jan 2008 05:18:52 +0000

In the spring of 1993 I was working at Landmark Petroleum in Fruita, CO and was knocked to the ground with static electricity. The arc was approximately 2.5 to 3 feet in length and was observed by our safety manager. The shock entered through the tip of my left index finger and felt as though I was punched, very hard, in the shoulder. Silica sand was being pumped THROUGH the PVC pipe that was approximately the same diameter and length as the one used in this episode. I KNOW they should revisit this “myth”. You can even purchase “grounded” PVC because of this problem.

By: bryan

bryan — Wed, 17 Oct 2007 19:35:48 +0000

In addition,magician Ricky Jay can penetrate the skin of a watermelon with a playing card(I didn’t see this episode-I thought they consulted w/him on it.)He does it on youtube.I would think he could get a card to go pretty deeply into skin. They definitely need to re-look at this and consult Jay.

By: AlwaysWrecked

AlwaysWrecked — Fri, 14 Sep 2007 00:05:21 +0000

If any of you watched the World Series of Poker from 2002 or 2003 there is a segment they included in one episode called “the nuts” which focuses on the odd and sometimes obscure parts of card playing. In one such section Chris “Jesus” Ferguson threw cards at various vegetables, slicing them all in half from a range of 6 to 10 feet. Being able to cut a carrot in half with a single stroke like that, although that may not be a lethal force on a human, would definitely break the skin. I think they should re-visit this with Ferguson as a guest and see just how deep his card throwing tactics can cut.

By: Dinj

Dinj — Tue, 14 Aug 2007 20:39:14 +0000

Wow…yeah, looked up that story…I think that “small cut” means its plausible though. I mean, hit an artery or vein, and bam, they could easily bleed to death. This one needs to be revisited.