Author Topic: Is a pump, a pump?  (Read 2301 times)

red_tx

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Is a pump, a pump?
« on: April 19, 2021, 02:56:35 PM »
team wingers,
I have sling pump that I have used on a Sling 4'2 and a 5'4 without issue.

I bought Keys' 7'2 Naish and when I pump it up with my sling pump, boy its tight even getting it to 7 PSI. And I feel like its going to pop. Everything seems fine at 7PSI, but I dunno, it just felt like more of a struggle getting to 7 PSI..

I am guessing because its a larger kite with more total volume, I just wouldn't expect it to feel like it was going to pop. I imagine the fancy little Naish valve may have something to do with this as well. (?)

If anyone responds with, "no red a pump is not a pump and you need a naish pump", then i quit.

Thanks in advance
-red

Dwight (DW)

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Re: Is a pump, a pump?
« Reply #1 on: April 19, 2021, 03:04:26 PM »
The pressure gauges on pumps are famous for giving bad readings. Use instinct.

red_tx

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Re: Is a pump, a pump?
« Reply #2 on: April 20, 2021, 11:14:04 AM »
Thanks Dwight, I assume that you can pop the bladders by over inflating. Now I am having flashbacks to when my Sling 4.2 popped a center bladder on the wrong side of the lake one day.. long paddle back

Did I over inflate it? Maybe.. Did it just fail.. Most likely.

What is the best pump in your opinion?
-red


Dwight (DW)

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Re: Is a pump, a pump?
« Reply #3 on: April 20, 2021, 12:39:58 PM »
....... center bladder on the wrong side of the lake one day..

Did I over inflate it? Maybe.. Did it just fail.. Most likely.


Depends on what popped, the inner bladder or the outer casing.

The inner bladder can fall away inside the carcass. This happens at the front usually. Some brands have a little string with knot coming through a hole up front. This is to tie inner bladder to the front. Preventing it from falling away. If it falls away, it could fail to walk itself back into the front cavity during inflation. That’s when it pops. Gong wrote a piece on how people putting away wet wings and wadding them up, can lead to inner bladders becoming misplaced inside and then failing to re-seat properly during inflation. Popped wing. Always roll your wing up nice and neat.

If the outer casing failed, it was likely from a design error seen in several wings last season. Brands underestimated the stress on the top seam of the center strut. Lots of failures on that seam with many brands.
« Last Edit: April 20, 2021, 01:23:06 PM by Dwight (DW) »

bigmtn

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Re: Is a pump, a pump?
« Reply #4 on: April 20, 2021, 02:06:32 PM »
If the outer casing failed, it was likely from a design error seen in several wings last season. Brands underestimated the stress on the top seam of the center strut. Lots of failures on that seam with many brands.

I wrote F-One about this. Bought a barely used f-one swing off a buddy, and noticed a little bulge in the seam on the top of the strut above where the back handles are.  Their response was that it is due to underinflating the wings (to the wrongly suggested 6psi that they put on the wings) and that they now recommend going to 8-9 instead.  The stitching starts to come apart from the stress of the strut bending near the handles. All my friends swings had the same issue. Though the other swing I owned, which I always pumped to 10 thanks to Admin's advice, didn't have an issue. Quick trip to the repair lady, and she just reinforced the stitching along the top of the strut.

SimonP

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Re: Is a pump, a pump?
« Reply #5 on: April 20, 2021, 02:21:29 PM »
I wrote F-One about this. Bought a barely used f-one swing off a buddy, and noticed a little bulge in the seam on the top of the strut above where the back handles are.  Their response was that it is due to underinflating the wings (to the wrongly suggested 6psi that they put on the wings) and that they now recommend going to 8-9 instead.
That's interesting. I've always pumped to 8 psi because the Swings just do not work as well at lower PSI. A year's hard use and the stitching is starting to separate on my 5m.

Dwight (DW)

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Re: Is a pump, a pump?
« Reply #6 on: April 20, 2021, 05:44:37 PM »
Taken from the Naish S26 web site

Finally, new internal reinforcements and advancements have been made in seam construction, especially in high load areas such as strut to leading edge connection and strut to canopy stress points — all contributing to a stronger and longer-lasting wing

Harness users exposed the issue first. A harness puts higher loads on the wing. Gong, Ozone, Fone, Naish all had a few issues.

PonoBill

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Re: Is a pump, a pump?
« Reply #7 on: April 20, 2021, 07:54:27 PM »
I was going to go to 11 when Admin went to ten, because Spinal Tap--but then I looked at the sausage link effect on some of his wings and went to 9. The harness line issue seems pretty fricken(I'm sort of cleaning my language up) obvious--hanging your entire weight off two little attachment points? I think not. One more reason for a fake boom. My weight hangs from all three handles.

Oh, and I think all the pumps are made by the same two guys and a dog somewhere in China. There really isn't a nickel's worth of difference between them. The volume of the kite or wing makes no difference in how much force you need to apply to reach some specific pressure, just how long it takes and how tired you are when you get there.
« Last Edit: April 20, 2021, 08:28:19 PM by PonoBill »
Foote 10'4X34", SIC 17.5 V1 hollow and an EPS one in Hood River. Foote 9'0" x 31", L41 8'8", 18' Speedboard, etc. etc.

 


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