[QUOTE=baddbob Also you may want to adjust your trigger travel down so less material comes out for better atomization- the gun may be putting out more product than it can atomize. Or buy a better gun. I spray all automotive colors and clears with a 1.3 and a 1.4 tip without problem. Bob[/QUOTE]
Since I think your a professional painter?? I thought you might be interested in the following with regards to the 1.3 tip.
Careful with clears and that 1.3. The semi hyper clears and hyper clear such as 3000-ppg, 4700 & HC7600 DuPont. 4400? I think in Basf, the 1.3 can cause problems. The 1.3 will work majority of time but on a real humid day with warmer temperature you can experience solvent pop and very hard buffing the next day. This will also show up if you wet your booth down on a warm day.
What is happening is the 1.3 is over atomizing the clear and the tin in the clear is putting to much water in the isocyanate causing the clear to kick way to fast.
From what I have seen so far don't expect your paint rep to have a clue as to what I just said as I don't think they have a clue yet. Because it only happens when conditions are right and not all the time they at this point just pointing finger at the painter.
Because the hypers are so expensive a lot of shops avoid them anyway.