On Wednesday, January 27, 2016 at 7:44:01 AM UTC-5, wrote:
On Sunday, January 24, 2016 at 12:32:25 PM UTC-5, wrote:

For acrylic urethane I use a turbine HVLP system which gives a big pattern and has no water in the air. I can't make myself use my $400 gun for polyester topcoat so I do get a few fish eyes in that.
FWIW
UH

I know guys that are serious about painting are particular about
what goes through their guns -- never put primer through their
favorite gun and so on. But what's the rationale for this? It
seems to me that the paint follows such a short path through
the gun that it can't cause any serious wear. At least for
gravity feed guns. Are there other issues?

Jim Beckman

i have a favorite gun, i'll put primer and topcoat through it. it just needs to be thoroughly cleaned. if there is residual junk in the gun, even stuff around the cup lid, it can end up in your topcoat. thats probably why most people are weird about it. the primer itself has no negative effects on the guns ability to shoot paint.