I need advice or additional hints on how to handle rust in a shower drain.
Our landlord installed a shower with a shallow drain. The drain is fixed with 3 screws and a big seal that fits the rim of the drain whole above and beneath, consider it U-shaped. I discovered a missing part in the seal, at least on the upper side, and opened dismounted the drain founding rust on the enamel upper side of the shower.
Now I got a new seal and will change the broken one. How should I handle the rust part? I would go with a bit of sandpaper and clean the rust off, but then? Should I use some sort of coating before remounting it with the new seal?