I'm new to the AB, so I need to gauge the amount of paint to apply a basecoat on a typical 1/35 AFV.

Can anyone give me a ballpark figure (eg. 0.5 ml, 1 ml, etc.)?

less than you think, but more than you buy. but seriously
i usually can do it in two pots(tamiya/humbroll)when spraying.
if your new to spraying you may need more paint as different colours require more or less thinner and certain primer colours will require more paint to cover. i usually buy a little more than i need as it can go into my paint stock.

Two pots? Holy crap, I did my centurion with about half of a Tamiya pot thinned 50/50, pretty sure it wasn't too thin.

When I do a typical tank, I go through 1 to 2 pots for the whole project, that includes base coats, shading, and higlighting. For just the base coat any where from 1/4 to 1/2 pot, depending on thinning and whether I do some preshading during the base coat.

I always tend to mix more then I use, mainly because I am always worried about running out. I should probably have some extra bottles and keep some of the basic base coat colors pre-thinned, might not use as much then.

By a "pot", do you mean the cup of the AB (typically 1/3 oz)?

About 3/4 to 2 oz total of thinned paint. A lot depends on how many different colors I'll be using, since I tend to toss out any thinned, but un-used paint rather than return it to the original container.

I usually don't mix in quantities much less than a 1/4 oz.

HTH,

I am meaning bottle or tin(humbrol) of paint. The only paints I don't go through a lot of is Vallejo Air, as it is thinned already.

Maybe I am the anomaly here but I rarely go through a 1/2 jar of the little tamiya pots and I think I have a heavy hand, but maybe not.
Chris I usually mix my own paint colours with the Tamiya paints and put them into a 35mm film can and then thin it pretty well with windex. If I fill a 35mm film can 1/2 full of thinned paint I can cover quite a bit including two to three solid layers of the base coat and lots of touch ups (I am not the tidiest painter. . .). I have found that I use less paint with a gravity flow than a suction type AB. If you are mixing your own clours my recommendation is to mix a bit, get the colour where you want it then mix up a full 35mm film can size container 3/4 paint to 1/4 thinner or so, and use it for the whole thing. If you really like then colour write down a cheat sheet of what went into it so that you can replicate when you run out. Cheers.

I rarely go through more than 1/2 a pot, per model. I build up layers of a very lean mix, about 70:30 thinner to paint. Even running this through a heavy tip it rarely takes more than three coats. For the camo pattern, I use about 60:40 thinner to paint. However, if you are using MM acrylics, you can't thin the paint much more than it already is. This draws the conclusion that it depends on which paint you use. I recomend MM enamles and Tamiya acryls. Vallejo may be your best bet, but I haven't tried them.

I'll use only Tamiya acrylic paints for ABing (Vallejo for hand brushing). Since it's not easy to get Tamiya acrylic paints around here, I just don't want to run out of paints in the middle of a painting session.

What the heck...I'll just order more Tamiya paints :-) 40-50 large bottles of basic colors should last for some years, assuming I build 5-6 models a year.

for common airbrush cup size, using a 3 to 1 mix ratio (model master enamels), i usually cover an entire kit with about a half of a cup worth for a base coat. will use even less when doing preshading/highlights. (give or take- i havent paid really close attention to exactly what i use)

as far as how much paint i actually use, i have never really paid that much attention, but i dont use over half of a jar.