Learning to paint....

After having a great conversation last night over dinner with an old friend (very talented retired painter/body man) I've decided I should get a second gun so that I can have one for BC and one for CC to prevent any accidental contamination in the CC.

Other than the tip size, what should I look for in a second. My current gun is the Devillbis FLG4. Does clear shoot significantly differently somehow that would prompt a "different" gun or do I just get another FLG4 and call it a day?