Thanks for all your replies. I hadn't thought of the modified electric pump, and I looked into the foot pump but it was a bit too large for me. However, I think I found a solution that works pretty well combining the inflation bag with a high-quality balloon hand-pump (which I believe is similar to the old 2000-era Wipika style pumps). The problem I was having before was that I using a low quality exercise ball pump. After the kite reached about 3-4psi, the air would start to backflow out of the pump. So until someone pointed out a higher quality version of the hand pump, I was using a mini bike pump, which took an exteremly long time.
So my solution is as follows. First I use the Alpacka inflation bag to pump the kite up to about 0.5-1psi. Basically, this gets a large volume of air into the kite at a low pressure. Beyond this pressure, air simply rushes out the seams of the inflation bag (even if they are sealed), so I then switch to the high-quality hand-pump to get the kite up to 8-10psi. Using this system, I can leisurely inflate a 9m kite in 6-7 minutes without expending too much effort (much less effort than it would take using the hand-pump alone). Actually, the time using the hand pump is quite short. I'm not pushing in a lot of volume with the hand-pump, just enough to increase the pressure. It's not as easy as using a standard kite pump, but the entire set-up easily fits in a backpack measuring 12" by 8", and weighs less than 1 pound.
So for anyone interested, here is my recipe:
1. Qualatex ($7) or Gymnic ($15) double-action hand-pump
- Both of these pumps seem to work, but many hand-pumps do not.
- I used a Dremel to cut about 1/4" off the tip so it would fit better into the kite valve.
- I'm guessing the old Wipika kite pumps would also work, but I haven't tried.http://www.amazon.com/Balloon-Inflator-Qualatex-Perfect-Animals/dp/B0017RO9HKhttp://www.amazon.com/Gymnic-Faster-Blaster-Power-Double-Action/dp/B00792GN6W/ref=sr_1_78?ie=UTF8&qid=1349381236&sr=8-78&keywords=air+pumps
2. Alpacka inflation-bag ($15 + shipping)
- The video on the Alpacka website is helpful.
- You have to be careful not to have any twists in the bag near the nozzle.https://www.alpackaraft.com/index.cfm/store.catalog?CategoryID=52&ProductID=74
3. Sil-Net tent seam sealer ($8) and quilting loop (this I got from a local fabric shop)
- Without sealing the seams, the bag stops pumping the kite at a much lower pressure. - If you put on the seam sealer without pre-stretching the seams, the seal will easily break when the bag inflates.http://www.rei.com/product/705425/gear-aid-silnet-silicone-seam-sealer-15-oz
4. Sea-fit nylon hose adapters and nylon hose (see attached pictures). I found these at West Marine for under $10 total:
- 3/4" Female NPT (National Pipe Thread, which is standard) to 1/2" barbed-hose adapter (NPT stands for National Pipe Thread, which is standard. This fits into the 3/4" male NPT connector on the inflation bag).
- Roughly 9" of 1/2" diameter hose
- 1/2" barbed hose to 3/8" barbed hose adapter (3/8" fits all the kites I have owned, which includes North, SS, and now BWS - benwilsonsurf noise kites).
The entire set-up fits in a Curve Surf hydration bag that's made for surfing (basically a small backpack with an ingenious chest strap that allows you to duck-dive a wave with it on). It's a short pack that easily fits above my waist harness. http://curvesurf.com/waterman.html
I take out the hydration pack and put the inflation bag, hand-pump, and nylon tube+adapters in a Seal-line waterproof case. I'm using the eSeries 18 for now.http://cascadedesigns.com/sealline/e-cases/eseries/eseries-18/product
So, thanks for your help. Obviously, it's a pretty involved process to put this all together. However, if you don't want to leave anything behind on the beach, at least you know this option can work. Also, I would definitely appreciate any ideas to make this better.