Hi guys,

I have been spraying today with my Revell Standard airbrush. It has gone very well all day. However, when I came to spray some Tamiya Acrylic Yellow (i'd been spraying acrylics all day) things got bad. The brush wasn't applying an even coat, making it very patchy yellow. Also if I kept the brush in the same position for 2 seconds or more, it started to blow the existing paint on the model around creating "spiders legs". I cleaned my brush out but it still happens.

The paint can't be too watery as when I first tried it, it was purely tamiya acrylic yellow orange and white.

I'm lost for ideas. Thanks guys.

After long spraying some moist/water could cumulate in air hose. You should remove air hose and make sure there's no water inside and this should do the thing.
The second idea is badly stirred paint causing clogging airbrush but more probable is spraying too diluted paint from too close and too long in the same, but first pls check the air hose.