Steve, those sprayers are usually sold, as I noted, for glaze
applications in ceramics, and most ceramics supply places (the
better ones, at least) will carry them. When I was in art school,
the local book store which also carried lots of art supplies for
the art department carried these things, and they’re still
widely used, or so I believe. Or you can make one. They’re
really simple. One tube, about 1/8" in diamter (outside
diameter) and about 6 inches long, is the vertical tube that goes
in your liquid. at its top end is a simple bracket (hinged in
the commercial ones to allow you to fold it up and/or adjust it)
that holds a second tube, about twice that diameter by the hinge
and flaring slightly to a wider end into which you blow. It’s
usually about 4 inches long. The end of the wider tube butts up
against the side of the end of the longer tube, so when you blow
in the flared end, the air stream goes directly across the end
of the narrower feed tube. That creates a venturi effect, which
sucks whatever liquid the narrow tube is dipped in, up where the
air stream breaks it up into a fine spray. The sprayers last
almost forever, and cost just a couple bucks or so.
That’s more of a description than you need to buy one, but it
will let you make one if you’re so inclined. The commercial ones
are real cheap stamped tin plate or something. Some perfume
spray bottles work on a similar principle, and might work. These
would have an air bulb you squeeze to blow across the end of a
similar, though smaller, dip/feed tube on the bottle.
Or, an external mix air brush is also doing the same thing, by
blowing across the end of the feed tube… Harbor freight sells
a cheap chinese made external mix air brush for about 14 buck
normally, and on sale at regular intervals for about 6 or seven
bucks. It works fine too.
And some folks have used the type of sprayers used for asthma
inhalers or nasal spray bottles. I’ve not, so cannot be more
specific, but if you’ve got a buddy with asthma and some
discarded inhalers, it might be worth a quick try.
Hope this helps. Feel free to contact me if you need more info
or ideas on this.