I'm working with a non-profit (little money) group the rust and repaint a 1.5 story steel stairway on their building. Hasn't been painted in ant least 30 years. We need to strip the rust before painting.
Our first thought was to sandblast it, but it turns out that none of the rental places rent sandblasters any more due to regulations requiring self contained breathing apparatus to sandblast. So, we're down to either hiring a commercial firm to come blast it (expensive and they're short on money) or trying something else. We could buy a sandblaster, but no one has a compressor with enough CFM to drive it hard, so we'd probably have lame results.
We can wire wheel the large supports, but the treads themselves are a grid like pattern of steel with too little space between the steel grid to even fit in a wire brush, let alone a grinder & wire wheel.
We've tossed around the idea of using a pressure washer. Opinions vary on whether or not a pressure washer would remove the rust, scale, and loose paint to a level where we could paint it or perhaps use some of that "extend" type sealant on it to convert the surface rust before painting.
Comments? Ideas?