I finally broke down and had a few of my steel casement windows sent out to be restored. I've blogged before that I'd like to restore them myself, but with the winter here and a new job I figured I'd try out the professionals. There was serious rusting on the bottom of the window frames that mount in the building, so before I sent them out I sanded and treated with Rust-oleum heavy rust primer.
The company I'm working with is Metal Man Restoration in Mount Vernon, NY. They came and picked up and removed the windows- something I suggest having a professional do since they are heavy and we're on a high floor. If they fell they could do some serious damage to the building as well as to someone walking by.
Metal Man's process is to put the windows into a paint removing bath to strip them down to bare steel. Next step is to remove the glass panes and old glazing. From there they spray the window frames down with a metal paint, replace the glass, and put in linseed-oil-based black window glaze. This is allowed to dry and then they are remounted.
Below is a picture of the windows while they are drying after their paint job.
More to come when they are re-installed.