slow rollin

Just wanted to say thanks for making this thread. I got a road bike that was sitting outside under a tarp for a long time, and I didn't think of using either evaporust or gun cleaning equipment(which i have). Mines quite a bit worse then OP's and if this can help I will do it. Was also the whole seat tube since the PO clamped a 26.4 post in a 26.8+ seatpost frame.

cemark

Thanks to him I cleaned up almost all the rust from my seat tube. I saw that video. It was really practical and cheap solution for the rust. The seat tube and bottom bracket junction prevent me to clean up properly though. I will try to do it again with the combination of that video and suggestions here.

cemark

Wouldn't existing rust make it worse if not removed?

Duragrouch

Depends. Some external building sheathing is designed to rust a certain amount and then stop, leaving it a uniform brown. That was fashionable in 1970s construction, don't know if still is. For normal consumer goods, the rust, due to its porosity, is more apt to hold water and salt, thus may cause acceleration of rust. Smooth original steel finish, the water may bead up and roll off better. However, slight porosity in the surface can hold more oil; Example is the "parkerizing" gray-phosphated finish on military firearms, it's designed to be non-reflective, but also hold oil better, for rust prevention. It also itself has some anti-corrosion properties, especially if it incorporates a chrome-sealer in the treatment. Better quality steel painted car parts these days are phosphated before paint, that also helps the paint grip better. Paints and primers designed for rusty metal, have an oil base that is thin enough to penetrate the rust, to seal it off, though you still need to remove any "scale" to the rust, get down to the base layer.