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Maintaining Used Kevlar on Staff/Poi

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#157719 - 09/09/03 11:41 AM Re: Maintaining Used Kevlar on Staff/Poi
Charles Corporate Circus Arts Entertainer Registered: 27/06/01 Loc: Auckland	Ben-ja-men. You say when you stick the kevlar in a fire uncured the kevlar itself burns...How hot is this fire? I know the wick here at HomeofPoi will resist degradation until it reaches at least 650 degrees F. The kevlar in the wick wouldn't burn at all. Perhaps putting it in a fire that has been burning for several hours and near hot coals will destroy your wick. But the Kevlar itself shouldn't burn like cotton or some other combustable material. It will simply flake off and degrade, but it won't feed any energy into the fire itself. Well, thats my understanding of the substance anyway... _________________________ HoP Posting Guidelines * Is it the Truth? * Is it Fair to all concerned? * Will it build Goodwill and Better Friendships? * Will it be Beneficial to all concerned?
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#157720 - 10/09/03 12:03 AM Re: Maintaining Used Kevlar on Staff/Poi
Deimos Cinnamon Girl Registered: 22/08/03 Loc: Hfx, NS, Canada	Man, I just read this whole thread and realized everything that the girl I spin with is killing her wicks! Once, she got really pissed that her wicks were smouldering so bad and she assumed that there was still fire so she beat her poi against the ground... now it's all frayed and scary looking. I'll inform her to redunk now, and to be kinder to future wicks! _________________________ PLU*R
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#157721 - 09/09/03 02:39 PM Re: Maintaining Used Kevlar on Staff/Poi
adamrice poo-bah Registered: 19/12/00 Loc: Austin TX USA	The old curing story. I wish I knew where this started. So far, noone has explained the mechanism behind curing. I don't buy it. The story about keeping wicks moist also doesn't seem to have any logical mechanism behind it. Immediately re-soaking after extinguishing one's wicks does seem to make some sense. I haven't done parallel testing of this, but heat is clearly destructive to wicking (yes, even Kevlar). One thing I have found is that bigger wicks burn hotter, and deteriorate more quickly. This was a surprising (to me) result, but there you have it. Minimizing exposure to heat by quenching the wicks should help the lifespan. _________________________ Laugh while you can, monkey-boy
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#157722 - 09/09/03 06:35 PM Re: Maintaining Used Kevlar on Staff/Poi
ben-ja-men just lost .... evil init Registered: 12/06/03 Loc: Adelaide	quote: You say when you stick the kevlar in a fire uncured the kevlar itself burns...How hot is this fire? I know the wick here at HomeofPoi will resist degradation until it reaches at least 650 degrees F. The kevlar in the wick wouldn't burn at all. 650 K is only 380 �C "The outer core of the candle flame is light blue -- 1670 K (1400 �C). That is the hottest part of the flame" http://hypertextbook.com/facts/1999/JaneFishler.shtml this is for a candle, bearing in mind that the wick is in contact with the hotest part of the flame all the way through the burn. So the bigger your wick the hotter the temperature .... "Will not burn or smolder" http://www.thermostatic.com/techdata/kevlardata.shtml this is under normal use though not when it has been soaked in a flamable liquid and set on fire. quote: Extinguishing equipment: Blow out fire from the bottom of the wicking. If they don't go out after two blows place them on the ground and smother them with a damp towel. (Do not smother with a damp towel if that gear needs to be reused later in the performance. In an emergency, USE A FIRE EXTINGUISHER Do not let the kevlar wick smolder, as it will not last as long http://www.homeofpoi.com/fuel.htm _________________________ Our deepest fear is not that we are inadequate. Our deepest fear is that we are powerful beyond measure. It is our light, not our darkness that most frightens us. We ask ourself, who am I to be brilliant, gorgeous and talented? Who are you NOT to be?
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#157723 - 10/09/03 10:43 AM Re: Maintaining Used Kevlar on Staff/Poi
MillenniuM Hyperloops suck Registered: 10/07/03	quote: this is for a candle, bearing in mind that the wick is in contact with the hotest part of the flame all the way through the burn. So the bigger your wick the hotter the temperature .... Ah, I'll have to disagree with you there - College chemistry has told me otherwise. The hottest part of the flame is what's called the C sector. Here's a crappy drawing: code: [Top of flame] __ /D \ / \ / \ / C \ \| \| \| \| \ B / \ / \ A / \ / [Heat Source] Consider this is 2 dimensional, and in three dimensions, A would be right at the surface of your poi, whereas C would be suspended quite a bit farther away from the heat source, or fuel/kevlar. Try it: Melt something right at the surface of the flame, and melt it 2/3 of the way up the flame, and it will melt SIGNIFICANTLY faster 2/3 of the way up. Further, you say the larger your flame the hotter it is... quite the opposite. The larger the flame the COOLER the surface of the kevlar, as point C is a further distance away from the surface. Edit: Here's a better picture... the flame is the hottest where it starts turning purple, inside the red part.
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#157724 - 10/09/03 11:51 AM Re: Maintaining Used Kevlar on Staff/Poi
Charles Corporate Circus Arts Entertainer Registered: 27/06/01 Loc: Auckland	Yeah...thats what i thought too, i had to go home and do some research which baby didn;t let me do so thatnk you, Millienium, much appreciated. Also, Ben-ja-min, your link says that Kevalr doesn't burn or smoulder. That's correct, but kevlar wick isn't made soley out of kevlar, as 100% has a very low asborbancy, and looks all yellow and waxy. This why towelling soaks up so much more fuel than wicking, and also why it falls apart after a burn or two, rather than the wicking whichlast for flippin ages. Most kevlar fire wicks are a combination of kevlar and/or cotton and/or fibreglass. It is the cotton first of all that smoulders/burns. _________________________ HoP Posting Guidelines * Is it the Truth? * Is it Fair to all concerned? * Will it build Goodwill and Better Friendships? * Will it be Beneficial to all concerned?
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#157725 - 10/09/03 02:14 PM Re: Maintaining Used Kevlar on Staff/Poi
ben-ja-men just lost .... evil init Registered: 12/06/03 Loc: Adelaide	MillenniuM i thought that the flame structure was as u drew it with a layer around the outside that was a hotter temperature, i guess i was mistaken. quote: The larger the flame the COOLER the surface of the kevlar, as point C is a further distance away from the surface. i get that the c spot is further away from the surface but wouldnt the overall temperature of all the points in the flame be hotter? quote: It is the cotton first of all that smoulders/burns if thats true Charles then wouldnt the cotton burn away faster if the surface of the kevlar had not been oxidised ie burnt? _________________________ Our deepest fear is not that we are inadequate. Our deepest fear is that we are powerful beyond measure. It is our light, not our darkness that most frightens us. We ask ourself, who am I to be brilliant, gorgeous and talented? Who are you NOT to be?
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#157726 - 10/09/03 02:48 PM Re: Maintaining Used Kevlar on Staff/Poi
Charles Corporate Circus Arts Entertainer Registered: 27/06/01 Loc: Auckland	Nope coz the cotton is on the OUTSIDE of a thread of kevlar! Or sometimes woven with the cotton (but not many wicks are made like this). _________________________ HoP Posting Guidelines * Is it the Truth? * Is it Fair to all concerned? * Will it build Goodwill and Better Friendships? * Will it be Beneficial to all concerned?
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#157727 - 10/09/03 02:52 PM Re: Maintaining Used Kevlar on Staff/Poi
MillenniuM Hyperloops suck Registered: 10/07/03	quote: i get that the c spot is further away from the surface but wouldnt the overall temperature of all the points in the flame be hotter? Although the overall energy expensed is greater, as more excited atoms (fire) are moving, the temperature in any given point on the wick (excuse the lack of proper vernacular) is lower, only because of increased distance between the kevlar and point C. It's true that if you harnessed the energy released through the flame it would be a larger amount than having a smaller flame, temperature per area would remain similar.
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