Tubes rusting during construction.

[slepyhed]

I had the same problem on my build and never solved it. I ended up cleaning most of it off with a wire brush in an angle grinder, then I used the sandblaster to get in the corners (do this outside!).

Thinking back on it, I recall that the steel stayed mostly rust free for the whole first summer, then rusted over the winter. This was in my basement workshop - hardley exposed to the elements! I've since been considering a dehumidifier. My car is done and painted, but all the misc steel and machine tools are still exposed to the rust menace.