Hard water stains removed from a glass office facade

The Baldwin Offices, built in 1990, is a multi-tenant office building in Cincinnati with a facade given over almost entirely to glass. That is the look the building was designed around, and it is also why nothing on it can hide.

What went wrong

Hard mineral staining across the windows. Water with a high mineral content runs down the glass and evaporates. The minerals stay behind, build up, and harden. Left alone they stop looking like water spots and start looking like damage to the glass itself, because in effect that is what they become: the deposits etch into the surface rather than sitting on top of it.

This is the part owners are usually surprised by. Washing the windows does not touch it. A standard clean lifts whatever is sitting on the deposit and leaves the deposit exactly where it is, which is why a building can be cleaned on schedule and still look stained.

Why it had to be done carefully

Glass is unforgiving. Anything aggressive enough to take off bonded mineral deposits in a hurry is aggressive enough to scratch or haze the pane, and a hazed window is a worse outcome than a stained one because it cannot be undone.

Access was its own problem. Large roof signs had defeated swing stage setup on this building before, so the crew had to work out a safe rig before any restoration could start.

What was used

The windows were restored with Glass ReSurfacer Final Polish, worked across the glass with a Glass ReSurfacer Pad. That combination takes off the bonded deposits and the etching they leave behind, rather than polishing around them.

Once the glass was clear, Glass Defender went on as the protective layer. This is the step that decides whether the building is back in the same position in two years: the coating sheds water and stops new mineral deposits bonding to the surface, so ordinary cleaning keeps working.

How it held up

With the coating on and a maintenance plan to match, the restored glass stays clear rather than drifting back toward the state it started in.