While I wasn't looking the wife had someone power wash the basement steps. This stairwell is 12' wide and is exposed to both rain and direct sunlight. The power washing etch the surface of the concrete. This will in all likelihood cause spalling and chipping in the future due to moisture and freezing.

Need recommendation for a good sealer.

I have only sealed a chimney cap with some clear stuff I got at Home Depot. It's held up the last time I was on the roof.
I have the bottle somewhere.