The paint Im having the problem is started its life in an aerosol can which I had decanted into bottles to use with my airbrush.
Ok i used my airbrush a few days ago using acrylics with no problems. Cleaned it out, and ran a couple of bottle of plain water through it. Again no problem. Today I filed the bottle with the paint from the aerosol. I could not see any problem with it. I assume that since it was already thinned for the aerosol it would not need to be thinned for the airbrush. However it just point blank refused to spray. I cleaned out everything I could, the nozel etc, air flow was good but it still would not spray. So I returned it to its original bottle and cleaned up the airbrush. Sprayed out a couple of bottles of water and hey presto it worked fine. So I grabbed a bottle of Revell - thinned it to what I wanted and sprayed that. Again no problems.
So back to my question. What is wrong with the paint that will not spray?