[MPWR]

If you're getting spiderwebs when spraying lacquers, you need to add more thinner. You shouldn't need more than about 20 psi (a good gravity airbrush will usually spray properly thinned lacquers very happily at around 15 psi).

The paint may have thickened a lot by sitting on the shelf. That's why thinning by ratio is useless- there are too many variables for it to work reliably. If the paint needs more thinner, you just add more until it sprays well. Too much is when the paint starts to pool as you spray.