airbrushing with white paint

I like MM Enamel Flat White,then I will use a glosscoat on it if gloss is neded

I use MM Insignia White for the most part (Since Gunze is damn near impossible to find) I have to thin it down pretty well and use lots of light coats but for the most part I don't have any issues with it.

OldNoob

Golden makes a airbrush medium that has a milky appearance it might be good for thinning acrylic whites. It also has flow enhancers to prevent  clogging.  It can be found at A.C Moore or online

Ditto for me. I use craft acrylics and, as Shawker posted, use AppleBarrel or FolkArt white thinned with Golden airbrush medium (or, some times with Future) and it airbrushes fine. Haven't tried airbrush medium with Tamiya or other acrylics though. YMMV

For white paint I use the cheap stuff from AC Moore apple something as you said it goes bad too quick to spend money on a color I don't use much, but when I do I just go buy a new bottle for 50 cents.

Golden makes a airbrush medium that has a milky appearance it might be good for thinning acrylic whites. It also has flow enhancers to prevent  clogging.  It can be found at A.C Moore or online.

I've had very good luck using Scalecoat II white.  It goes on smoothly, dries with a semi-gloss sheen for decaling and never has yellowed

I've had no troubles with white paint, that being Gunze. Tamiya seems fine too, but I have had their white thicken up and go bad quickly in the bottle, causing me to chuck it, because extra thinning didn't help it. I don't touch enamel paints so can't comment on those.

iv not found a white that likes the airbrush yet