With your permission may I add a thought? If you aren't using the heavy cast connectors and fittings on your conduit, then they are made from aluminum, right? so you would have a steel to aluminum connection there. An experience that I had, I recently had opportuniy to open a wiring trough built into a concrete floor. We were adding a piece of machinery for the first time in a long time, and all of the emt that was in the trough had rusted to nothing! The aluminum connectors were still there, but white and powdery, but the emt runs were just rusty powder in the bottom.
