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 Post subject: Re: Which kites have heavy duty bladder valves?
PostPosted: Wed Oct 03, 2012 9:44 pm 
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Hardly anyone has a 5th line.
For wave kites a fifth line is like Russian roulette as you know it will happen one day.

So you're alone on a beach with too much wind and then how to land ?
Pulling the safety isn't the real solution as the kite will spin.


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 Post subject: Re: Which kites have heavy duty bladder valves?
PostPosted: Fri Oct 05, 2012 3:46 pm 
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Hmmmm... I see... :?:


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 Post subject: Re: Which kites have heavy duty bladder valves?
PostPosted: Tue Nov 06, 2012 1:37 am 
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I thought that I'd pop this up for one more run. I am still looking to change brands. It seems hard to believe that all brands have these crappy valve attachments, and not one manufacturer has stepped forward to find a way to improve their products. Are there any brands that guarantee thier valve attachments???


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 Post subject: Re: Which kites have heavy duty bladder valves?
PostPosted: Tue Nov 06, 2012 6:25 am 
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nah, they all seem to do delam at some point, whether from hot, cold, humidity or some combination.
When asked all kite brands say the same thing, "we are working on it and ail have the newest, greatest system out soon" and no they will not guarantee them, ever.
good luck and if you do find one let the rest of us know..


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 Post subject: Re: Which kites have heavy duty bladder valves?
PostPosted: Fri Nov 09, 2012 9:53 am 
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Yeah... I am still waiting for that bladderless Nemisis that Best announced about 6 years ago.


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 Post subject: Re: Which kites have heavy duty bladder valves?
PostPosted: Fri Nov 09, 2012 11:06 am 
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my deflate valve of my 2012 North Evo (9m) is leaking. The seal between the male and female is , well, not tight enough. What gives? brand new kite, never leave the nipple in; while packed.

can't wait for some comments regarding my description :-) , but this is still a bit fkd that it's leaking.

So, nobody has the best bladders/ valves yet. They all suck one way or the other.
I would say we get what we pay for.... hey wait, we pay 2Gs for ... made in china..., never mind

PS: still love the kite though! :thumb:


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 Post subject: Re: Which kites have heavy duty bladder valves?
PostPosted: Fri Nov 09, 2012 4:27 pm 
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Beachboy wrote:
SO my question is what brands have? Please let me know if you've had kites that have never failed, even through multiple seasons? I'm ready for a change.


I've had Naish, Ocean Rodeo, Blade, and Liquid Force kites for multiple seasons and never had any valve issues with those brands.


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 Post subject: Re: Which kites have heavy duty bladder valves?
PostPosted: Fri Nov 09, 2012 5:06 pm 
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i´ve had RRD, Flexifoil, Blade and all failed

i got now Airush that didn´t fail yet, but it will once summer arrives

;-)


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 Post subject: Re: Which kites have heavy duty bladder valves?
PostPosted: Fri Nov 09, 2012 6:44 pm 
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Location: Hood River
Just for people looking for an explanation... This is not an excuse for delaminating valves, but perhaps it will explain what's going on...

Airtime, a company based in Hood River, who specializes in aftermarket bladders and kite repair (and they do a damn good job with both), has a specialized oven that they use to test the bond of valve to bladder, and they gave me a little information about what was going on. I know there will be materials engineers and other people reading this who know WAY more about this than I... If I'm right it's because Airtime is really smart. If I'm wrong it's because I misunderstood and I'm an idiot. If the latter is the case, please don't yell at me.

Apparently, the plastic used in making the valves is very brittle and hard on its own, so during production of the material, a certain amount of plasticizer is used. Plasticizer makes the valves softer and more pliant, so the valves are less likely to crack or fail in cold weather, plus they are easier to use.

Also, apparently, the type of plastic used in making the valve is different than the type to make the bladder itself. Different types of plastic cannot be heat welded together, so some type of glue must be used.

The problem with plasticizer is that over time, heat causes the plasticizer to leak out of the valve, and the plasticizer dissolves the glue, leading to a delamination.

Since 2011, we (North) have made significant progress at improving our valves and the connection to the bladder. I honestly don't know if we now are welding or if we've improved the glue or changed the recipe for the valves, but I do know that our new bladders do extremely well in Airtime's little oven test, and that complaints of delaminating valves have dropped off pretty much to zero for the last three years.

If you have had luck with particular glues working for reattaching valves or attaching new valves, it's possible that your glue is superior to the one generally used, however it is also possible that most of the plasticizer has already leaked out into the original valve (if reattaching an old valve) or that the valve you are using has less plasticizer than the original (if using a new valve).

No matter what brand you buy, you could end up with a fluke bad bladder, and if you store your kites in your car trunk or uncooled shed in a hot environment, your valves will delam at some point. As with most other brands, North is constantly working to improve every aspect of our gear. I think we've got the bladders pretty well dialed at this point, and I think most other brands are in a similar position.

Anyway, hope this helps.

-Dan


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 Post subject: Re: Which kites have heavy duty bladder valves?
PostPosted: Fri Nov 09, 2012 7:07 pm 
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Location: Ford Lake, Michigan
that's really interesting dan.

if what you say is true than the kite companies could fix these problems by doing a flash sear of the valves right before they go on the kites, what you can do is after the valves have been formed and plasticizer added, you heat sear them so that the outer micrometers of the valve lose their plasticizer . . .

but maybe there is a production reason why a heat searing treatment won't work (maybe it would deform the valves.

or maybe instead of making the valves out of PVC with plasticizer added they could make the valves out of polyurethane (which is what the bladders are) and add hardener instead of softener

In any case it looks like the basic problem is that kite manufacturers have no control over the actual valve production they are using valves meant for beach balls, inflatable mattresses and rafts, and adapting them to their own use instead of developing a specific research and development project to produce a better valve.

there's absolutely no question this is a problem that could be solved if you hire a engineer and throw some money at it.


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