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Any one tried permanent strut inflation

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Created by lostatsea > 9 months ago, 4 Apr 2013
lostatsea
WA, 147 posts
4 Apr 2013 5:56AM
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I have an old slingshot 17.5 machine for light days, thinking of inflating the struts with an expanding foam to permanently inflate the struts, kite is worth nothing so not worried about resale just want to save time pumping up, any one done it or have a better idea?

Troyrotor
QLD, 318 posts
4 Apr 2013 8:11AM
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I reckon the kite will end up so heavy and will end up needing over 15knts to fly

coastflyer
SA, 601 posts
4 Apr 2013 8:56AM
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Interesting idea, but your main problem will be the weight. Expanding foam from a can is relatively heavy, and each strut filled with foam will weight about 1-1.5 kgs. Your light wind kite may struggle to fly! Use this calculator to find out your strut volumes and it will give an idea of how much foam will be needed.

www.online-calculators.co.uk/volumetric/cylindervolume.php

2 LB Density Urethane Foam
(U.S. Coast Guard Compliant Marine Foam)
Common Applications: Our 2LB density marine foam is recommended for void filling in nonstructural applications. This product can be poured underneath decks and inside cavities where a lightweight flotation foam is needed to provide buoyancy. This foam has been tested in accordance with U.S. Coast Guard Regulation # 33 CFR 183.114 . This foam is approximately 95-98% closed cell which resists absorbing water, however continuous water submersion can eventually lead to loss of buoyancy over a period of years. We recommend this product strictly for flotation applications. If looking for a liquid foam for sculpting or casting we recommend using at minimum our 3LB or 4LB density. More questions? [Try our Foam FAQ.]

Cat No.
Kit Size(net weight)
Approx. Coverage
Price
FOAM-0204
4 LB Kit
2 Cubic Feet
$22.50
FOAM-0216
16 LB Kit
8 Cubic Feet
$67.00
FOAM-0280
80 LB Kit
40 Cubic Feet
$264.00
5 or more kits of the FOAM-0280
$252.00 / Kit
Drum Pricing (Kit Size 1033 LBS)
Coverage: approx. 500 cubic feet
Call for current price
Product Information:
Free Rise Density: 2.0 lbs per cubic ft.
Expansion Rate: Approx. 25-30x Liquid Volume
Buoyancy (flotation): 60 LBs per Cubic Ft.

*Physical Properties:
Parallel Compressive Strength: 40 psi
Tensile Strength: 30 psi
Shear Strength: 30 psi
Flexural Strength: 50 psi

lostatsea
WA, 147 posts
4 Apr 2013 6:39AM
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my two concerns are weight and how much flex will the foam take, dont want the bladder creasing, ill try filling an old knackered bladder first to see if possible and get an actual weight

polykarb
VIC, 284 posts
4 Apr 2013 10:23AM
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Lol, buy a battery pump.

Or use an old air/water extinguisher that you can be primed with just air from a compressor.

Or a high volume 12v portable compressor, I have one in my ute for inflating my iSUP.

LostDog
WA, 445 posts
4 Apr 2013 8:23AM
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Some kites allow you to leave the struts inflated using a simple cut-off valve between LE bladder and struts.
The next time you pump all you need is the LE volume and a little top-up for the bladders. I too believe your mass will be too much using anything heavier than air.

And because only negative feedback on this site is allowed I have to say - "Shi'te idea mate!"

lostatsea
WA, 147 posts
4 Apr 2013 8:23AM
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tried that, the pilbara red dirt f*%ked it after a couple months, might try the extinguisher idea but

Saffer
VIC, 4501 posts
4 Apr 2013 1:05PM
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This might work but i suspect it's not cheap.

www.huffpost.com/entry/lightest-material-earth-carbon-aerogel_n_2980978

borntokite
27 posts
4 Apr 2013 11:01AM
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All I can say is lazy bastard......

lostatsea
WA, 147 posts
4 Apr 2013 11:32AM
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HA, pretty much, i work FIFO week on week off, its with the quiver of gear i leave at work, only get a hour or two after work each day so every moment counts

Olliefly
QLD, 63 posts
5 Apr 2013 2:53PM
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i used beans from a bean bag once cause couldnt get a strutt bladder for my piece o **** Cabrinha, and still cant, They were light as.

GalahOnTheBay
NSW, 4188 posts
5 Apr 2013 4:11PM
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lostatsea said something along the lines of...

I have an old <snip> strut <snip> just want to save time pumping up <snip>




kiteboy dave
QLD, 6525 posts
5 Apr 2013 6:23PM
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Olliefly said...
i used beans from a bean bag once cause couldnt get a strutt bladder for my piece o **** Cabrinha, and still cant, They were light as.


Did it work? Sounds like an almost reasonable idea, possibly lighter than expanding foam anyway?

Troyrotor
QLD, 318 posts
5 Apr 2013 10:11PM
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Pick up a bean bag and compare that to a ballon the same size. The beans are heavy

iandvnt
QLD, 581 posts
6 Apr 2013 6:16PM
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Just awesome.... Please can you do leading edge with a load of cans of pu foam and post a video of session. Might be an issue with a bigger kite...weight not sure . sounds like bean bag beans are the go for the struts.

THE DONG
VIC, 518 posts
6 Apr 2013 9:05PM
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I suggest filling them up with scrunched up newspaper...use magazines if wanting to use kite in water (newspaper tends to get heav y)



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"Any one tried permanent strut inflation" started by lostatsea