I use PPG 2021 with the DFX11 accelerator. i thin about 3 times what they recommend. the faster hardener will prevent stuff/dust from setting in and allows to dry faster since I thin it more. I thin it like this so that I can put it on thin, have it flow, no orange peel. i also keep a small touch-up gun ready to go with retarder, so if you get it too thin and it does not look wet enough or you get some overspray, the retarder sprayed with a light coat will help wet and get it to flow, but it dries quick, to typically no runs, unless you over-do it. If you do it right, it will look like it was buffed.