Again...applicable search has been completed, with no results - so forgive me if this topic has been discussed before!
Has anyone ever tried using compressed air to fill their kite (eg: from a SCUBA tank)? I'm over unreliable pumps.....and figured since I have unlimited compressed air supplies, maybe it might be worth tiring out..!?
The main negative point I can think of off the top of my head is the reheating air issue (and looking like a tool
).
Physics 101 - gas moving from a higher pressure to a lower pressure will lose heat.
So when the cooler air heats up to the ambient air temp, it'll expand...and maybe make a gut wrenching pop noise!? The slower the fill, the less of a temp change...but still...(insert "thinking intensely" emoticon here).
Discuss
i know a guy who would fill up a small dive bottle and get about two kites out of it
The only concern I would have using compressed air is, you would have to be really careful not to over-inflate and pop a bladder. The hassle of annoying pumps would be far outweighed by the hassle of repairing your bladder!
Road Cyclists have compressed air bottles for inflating tyres up to high pressures and this is a common problem. You have a pinch in your inner tube and the rapid inflation by the bottle prevents you from picking them up, thereby creating another puncture.
I have used the same pump for 3 years with little hassle - just some regular spraying with Silicon lube and being careful not to let sand get into the intake.
@ Dr.- I think the PFD inflator's are operated by Co2 cartridges, and would have an over inflation valve so they don't pop. Similar I guess, just kites don't have the over inflating release luxury..
@Lil. - It would have to be a slow/controlled/careful fill to avoid the pinchy issue... I'd set the regulators intermediate pressure (the pressure the 1st stage of the regulator reduces the high tank air pressure to) very low...around 8 or 9 bar should be heaps..maybe?
My old pump was awesome, then it just died... so far the replacements have not been up to scratch! (so I'm trying to avoid forking out any more cash and use the stuff I have around me)..
@Rhino. - With the little 3.5l tanks I have, filled at 250bar+, it should fill quite a few kites...probably..around the 1000l of air (excuse the on-the-run math job!)
What's the average kite bladder volume?
^^^^ @ Craig. - Even though I knew what was coming I still pooped a little!
These guys use a liquid Co2 version... pricey and a pain in the ar5se to get filled.
just drop into the petrol station on the way down to the beach and pump up at the air hose
Another thought / idea if the compressed air thing works -
You could use one of the mini-bottles (similar to those used by some big-wave tow-in surfers) as a back-up if you crash your kite and open the deflate valve on a long down winder.... would have saved me a long walk the other afternoon!
I attempted one a few years ago it consisted of a 1kg or 1.5kg hand held fire extinguisher emptied ....drilled a hole in the base and fitted a tyre valve ( from tubeless tyre ) grommet ( for air refills ) connected my pump hose to the other end.
It worked quite well in that it could be filled and emptied....but I found that the servo air supplies could not reach the psi required in such a small extinguisher to fill a kite. ie: Not enough volume. It filled about half. I could have used a compressor from home etc.... but as this was a home job I was not confident about driving around with a cylinder at 300psi in the car.
A bigger extinguisher bottle would solve this problem but it would need to be bigger than a 2kg one and they are about the size of a pump and 10 times heavier so the benefits are not really there. Who wants to carry that to the beach ?
Best option is a vehicle mounted ( or portable ) compressor 4x4 Style and about 10m of air tube attached to the pump fitting ....you can even fit a guage.
^^ So there's nothing left to do but head to the shed!
I might try it out - not fully inflated - and leave it in out in the 40C heat for a while, see how much it expands....Should I pre-order a new bladder now/
Someone really needs to ask the Mythbusters guys to do a water sports special
Where’s RADMAN????
He’s just rigged up the ultimate in lazy-arse Kite inflation systems…. He has mounted a compressor under the bonnet of his Hilux. Then got a fitting on the back of his ute tray which you can just plug the hose into and pump away…. He’s even got a fancy on off switch on his dashboard!
It’s an awesome setup, the only problem is that you can’t get a park near him at the beach anymore, cos everyone is crowding around to pump up their kites!
How about posting some pics RADMAN?
How much it chills is solely dependent on the change in pressure of the gas and has absolutely nothing to do with the rate of fill. It may appear to not chill as much at low flow, but that is simply because at the lower rate it takes longer for the metal around the valve/reg to cool down (which is heating the gas back up again), but over a long enough time the final temp drop will be the same.
I use a high quality 4wheeldrive mini comp mounted in the back sidewall on the troopy
and a 6m hose with slingshot pump nozzle an gauge,does the job nicely,I tried cheap compressors they overheat an melt so spend the $ an get a good one that is rated to pump up a convoy of fourbys an you wont look back
yes I know I am lazy......but your just jealous
Also, you will find that temperatures for Pressure, Volume, Temperature are all related to degrees Kelvin, not degrees Celcius - so the actual variation in pressure due to increase in temperature will not be that much within the kite, even if the temp goes from 0 degrees celcius to 30 degrees celcius - that is only a 10% increase in degrees Kelvin.
Hey sunseeker i have got a set up on the old cruser i use it for lots of things .I am thinking of going to di this sunday should give it a go . Too everybody out there it is very simple just use and old air conditioner pump on your car engine .They are rated at 11 cfms wich is about 50 times bigger than a 4x4 air pump be carefull though it will pump up too 230 psi before it blows the seal out the front of it . I have a air tank and presure switch on it set at 120 psi the electic clutch on it disengages but i use a simple tap on the hose too keep control and not blow kite up too much , fill most of kite with it then finsh off with hand pump. hell half of you might have air con on car already that dosent work a little plumbing and wiring and you are on your way . Make the hose out of pump fairly long as it dose create heat . sunseeker look for a sh**ty brown landcruser with big ass wheels on it .
you need to use high out put low pressure,most of the compressors have low output high pressure apparently you can buy 12v small vacs like for your car that have reversable output so you can use as a blower which are high vol and low pressure will check them out,and most are
Rechargable or just run off cig lighter .
Easier solution would just be the electronic kite pumps or a cheap chinese 150L 4x4 compressor which goes for about $80 on ebay.
I use a 12 dollar air matress pump from and car shop. Pump up next to my car and leave everything there and walk to the beach. It will pump about 5 psi so I usually put 4-5 pumps of my manual pump to get it nice and firm. It's easy yet fool proof.
ha the lengths we would all go to .....We are all getting lazy or old or both
and I am just as guilty often pumping up my 8m instead of 10m just because it is fewer pumps I justify by telling myself "ahh the wind will pick up" the result several frustrating underpowered sessions marred further by the constant reminder of my mistake each time I attempt to pop and the kite stalls. 
hey smg, to regulate pressure you can just start to pull out the connection and let most of it spill as it starts to get full
to those with 4wd type compressors...does it take long? Might have to get me one.
