Well, after a lot of reading and research on straining Waterborne paint I found this little bit of info.
"The issue with waterborne chemistry and micron size pertains to how water resins cure. They dry by coalescing together to form a film, unlike solvent resins which dry by evaporation of the solvent into the air. A key difference is that a clotted hunk of solvent resin will re-dissolve in the presence of more solvent. A dried particle of waterborne resin that has clotted into a hunk won’t re-dissolve. As a result, several paint brands call for the smallest hole size (125 microns) to ensure that the final paint finish is perfectly smooth."
I found that when I was spraying BM Advance that I was getting some fine coffee grain bits that had not dissolved on the finished surface. So I called Gerson, who make paint strainers, and explained to them my problem and they informed me that they recommend 125 or 150 micron strainers for Waterborne. Now I was a little bit skepticle about this so I asked them if it was the same for house paint like BM Advance and SW ProClassic and they yes.
They sent me some samples for me to try.
So I thinned Advance, tinted Cloud White, with 10% water, used a 1.3mm needle and cap, my Q5 and strained it with a 125micron strainer, and guess what, no dried bits. I use to see these right away as soon as the paint touched the surface. Now the real test will be in a couple of hours when the paint levels and dries a bit.
Stayed tuned.
JC