Worked on the roof seem yesterday and today. I am using Evercoat's metal 2 metal body filler for the roof seam, both inside and out, topped by their Rage filler. The metal 2 metal works very well and is rust and moisture proof. Next the Rage top coat smooths it all out. After doing a couple of layers of that, I added yet another layer of fiber filled filler today to help keep it all from cracking out, which will then be skim coated with another coat of Rage when I'm done. I then hit all the exposed metal surfaces with One step rust coverter, for a total of three coats. Here are some shots from yesterday.