[arbys]

I need to do some spraying on interior house trim. Some will be urethane and some will be latex/water based trim paint. Would an HVLP paint gun work with my normal compressor? Would/could I also spray the latex through that gun? BTW I also have a normal spray gun and a HVLP turbine spray outfit. Suggestions for what I need to do?

[paint guy]

Urethane will probably work fine thru your HVLP, the latex will probably be too viscous to go thru either HVLP set-up (especially the turbine) without reducing. Probably have to reduce the latex to spray thru your conventional gun also, but maybe to a lesser degree. Some latexes will reduce rather quickly with just a small amount of water. You might find that when you get to an acceptable spray viscosity, the rheology will change and the latex will have much more of a tendency to sag.

[arbys]

Thanks paint guy, I originally bought the turbine sprayer to spray urethane on bookcase, fireplace mantle and staircase that I had built and stained. It turned out great.
You taught me a new word today, rheology. I had to look it up but it sounds like I'll just have to go by "trial and error". Doesn't latex require a larger tip?

[jetallman]

I never had luck spraying latex through my turbine sprayer, I do get a nice job with my spray tech ep2300 airless using a very fine tip, no runs and I've done thousands of feet of base and trim and quite a few doors. If you have an airless I can look at my tip size for you, I'm thinking its a 411

[paint guy]

A 411 airless tip translates to .0011" orifice size with an 8" fan width when the gun is held 12" away from the substrate (the part you are spraying). To decode airless tip sizes multiply the first digit X2 to get fan width, the second 2 numbers are the orifice size. On a side note, I have a customer that applies a specially designed latex metal primer to blasted steel and they achieve a dry film thickness (DFT) of 4-5 mils with one coat using an airless with a 621 tip (it's almost a garden hose).

[jetallman]

I paint latex on interior of homes normally with a 617, it also depends on your airless size, my smaller spx needs more tip to spray as fast as my ep, painted thousands of gallons with a 617 size