I wanted to follow-up on trying the Alpacka inflation bag (http://www.alpackaraft.com/index.cfm?fuseaction=store.catalog&CategoryID=52&ProductID=74
) as a portable kite pump. After a few tries, I was able to get the inflation bag somewhat working, but to be honest, it doesn't work very well. The problem is mainly the pressure needed in a kite is much more than what's needed in a portable raft, and the bag is not built to handle anything larger than roughly 0.5-1psi. The seams on the sil-nylon bag are only sewn (not glued or RF welded), so that the air rushes out of the seams once the pressure in the kite gets high enough. I used a tent seam sealer (used to waterproof tents), even making sure to stretch the seams out with a quilting loop prior to applying the sealer (see attached picture), but after the pressure gets too high in the kite, the seams start to leak through the sealer. The other issue is that the ball valves on the kites don't work all that well as a one-way valve, so the when the kite pressure starts to get high, there's a lot of leakage out of the inflation bag. I could add another one-way valve, but I think the main problem right now is the pressure.
I tried another inflation bag made by Fly Weight Designs, called the AirFlyte Dry Bag. The good news is that it can handle a higher pressure (about 2psi according to the people there), as it is a tougher nylon with RF welded seams. It also doubles as a dry bag. The bad news is that it's about half the size of the Alpacka bag, and therefore takes a long time to fill up the kite.
With either inflation bag, I still needed to take a mini bike pump with me to get the pressure up to 8-10psi (so it still takes a long time). Also, I needed to buy some nylon tubes and fittings (see attached) from West Marine to get the output of the bags into the kite.
So, I'm still looking for a good solution for a portable pump that I can carry with me (I am hiking into a spot to launch for a downwinder), but I wanted to follow up on my results with the inflation bag.