I have never been able to spray SW's Kem Aqua Plus to my satisfaction. Hated the stuff actually. But I had a gallon of it and wanted to use it on something where it wouldn't matter much if the result wasn't perfect. I built 4 large Baltic birch drawers this week and decided that was a good place to use some of it. And I also remember Trang's comment a while back that he added GF Extender to Kem Aqua Plus White and got very good results, and the photos he posted certainly supported that claim. So I got a bottle on my last trip to Rockler. I added 3% to the KA Plus and it sprayed like a dream; like a completely different product. W/O it I struggled to get a smooth film. It would be rough if I didn't spray a heavy enough coat or orange peel and run on vertical surfaces if I sprayed just a little heavier. With the Extender I can spray a 3 mil film that flows out to a smooth film w/o orange peel. I'd say it sprays as well now as my favorite all around product, GF's Enduro Clear Poly.
I've found a new problem solver.
John