Is one can of say Humbrol 78 enough for the dome and cheeks? Is one can of the grey 79 enough for the whole helmet or do I need to get more then 1 can?
One can should be plenty but grabbing 2 wouldn’t be a bad idea. Humbrol paints have to be thinned out quite a bit so the small 14ml cans actually go a long way!
As a general rule, however much paint you use, use double the amount of thinner. I.e for 3ml of thinner, add 1.5ml of paint. I used small disposable syringes to measure out and drop paint/thinner into the airbrush cup.
I’m not sure if it makes a difference, but for me I always put the thinner in first. I’ve had better results that way, instead of putting the paint in first and letting un-thinned paint seep into the nozzle and glob it up.