Take an old propane tank, ferret round eBay for a car tyre pump, a tyre valve and a handful of fittings, throw in a some 3d printed parts …
and you’ve got yourself a cheap airline.
I was dead chuffed with the 1/4" NPT tapered thread, especially as I was only half way through stripping it when I decided to stop turning the spanner.
I like the idea, but worry about draining condensed water. Without a way to drain it, how do you stop corrosion from within?
Fair point. I’ll check it from time to time, but I’m assuming the worst that can happen is I’ll find a pinhole leak one day. Then I can just get another abandoned cylinder.
Whatever else, it’s a big advance on blowing swarf out of blind holes with a straw.