A short update for those of you who are interested.
I've started dabbling a little more, this time, in a simple solder paste dispenser, for doing individual pcb's. (I normally do a train of designs on the same PCB - getting masks for each of them isn't always easy).
I tried using a regular aquarium pump, connected to a syringe with paste in it, and found that it works for a few minutes, but really - the aquarium pump simple doesn't have enough ooomph for anything over a two dozen bursts.
I then tried connecting my air compressor (harbor freight 3Gallon Pancake compressor) and was deeply disappointed to find that the compressor itself had a leak in it's output connector. (will be returning it to them today and hope that they are nice about it...).
Anyway, I noticed how loud the air compressor is in my little garage lab, and pondered if I really needed that big a system for a product that doesn't really use that much air (typically short bursts of less than a second). And then it hit me.
Couldn't I use small canisters of compressed air? I'd seen this over at hackaday: http://hackaday.com/2011/06/27/solder-paste-dispenser-hacked-to-run-off-compressed-air-cans/ but thought that it looked a little large and messy.
Here's my thought - how about using small CO2 cartridges - the kind that are used for food, or for blowing up tires.
This kind can be purchased at almost any sports store in the US. (They are also used in the old seltzer bottles - so they may be available in supermarkets too!)
I'll have more to report soon - just wanted to keep y'all in the loop.
/R