Complete noob here, so go easy on me. I've been learning a lot from this site about replacing floor pans and got this far. I plan on sealing the top with POR15 and then seam sealer (is that the right order?). But I realized I have no clue what to do on the bottoms side - right now it's just raw metal. I'm thinking I should have used something on the bottom BEFORE welding it in place but I'm past that point. And I don't think using POR is an option any more. In additional to sealing the seams on the bottom side what should I use on the bare metal (or at least the part I can see from underneath)?