We have several iron sky lights in our roof, and I have just plucked up courage to actually start working on one. Got it to open, and managed to scrape off a lot of the old paint, down to bare metal. I know there is something I should paint on the metal to neutralise the rust, before proper paint, but have forgotten what. Reminder?
The light is just like the one on the left, here, although without the cross pieces - we have two sheets of glass, not four :
There are a couple of nibs on the bottom, to prevent the glass sliding down, but little remains of whatever was originally between the glass and the frame. Putty, presumably. There is a gap at the bottom, between frame and glass, perhaps 1/10th inch. What can I squeeze in the gap, working only from inside? Putty with a knife? Some kind of silicone sealant from a tube? Any thoughts? Thanks.