It has now been a week since I applied the Mod Podge, and its starting to clear up. There are still some white areas which indicate thicker areas, which should be clear in probably less than another week.
I should be starting on the "Mark IV" mine cars pretty soon, so I could finally get a full train. Then I can determine if I need to re-do the desert.
No, I'm not modeling Nature's Wonderland in the winter with a frozen river! For water, I'm using a material called Mod Podge, which you can get at just about any craft store. When applied, it is completely white. As it dries it becomes clear and glossy. When this shot was taken, it was a few days after it was poured, since you can see some clear areas. It'll probably take about a week for it to become completely clear.