On Sun, 23 Oct 2016 11:04:05 -0700 (PDT), robobass wrote:

I make an unusual product (www.basscapos.com) which must be polished to jewelry standards, but includes a 5/16-24 threaded brass stud which is soldered to a brass bar. Torch soldering naturally produces firescale, which is hard to remove from the threads. There is a very effective product to combat this called Cupronil. You first preheat the work to maybe 600°f and then spray it on. It leaves a coating which protects the part. Works wonderfully. Problem is, I am going through it like mad. I have tried a bunch of different pump spray bottles, but none give me a nice focused spray pattern so that I don't waste the bulk of it. It wouldn't be such a problem if I could buy it in my country (Germany), but I can't. I suppose I should invest in an airbrush. I have a compressor, but I like the simplicity of a spray bottle, and the airbrush would still involve some experimentation to get it right. Can anyone think of an application where a precise pump spray bottle is used and easily
available? Cupronil seems to be similar in viscosity to water, but it is enough different that a bottle which gives a perfect spray pattern with water isn't very good with Cupronil.

Thanks!

Consider trying an olive oil / vinegar sprayer, something like this:

http://amzn.to/2ew5fbB