I am painting an Oliver Hart Parr 18-28. I have painted these tractors before using PPG Delstar acrylic enamel with great results. That product is no longer available in my area and my supplier recommended the Omni MTK urethane over the MAE enamel. I used the MAE on a MM corn sheller and coverage on pitted surfaces and castings was a problem but 4 coats covered. The MTK with tree coats will not cover on the castings and pitted parts. It covers fine on flat smooth panels. It is being applied over MP170 epoxy primer. I am mixing to the recommendations. Is anyone else having coverage issues and what do you do to correct them? I am thinking of trying a fast dry reducer and less of it in the ratio.