Still working on a Trek frame, but mine had the dreaded sweaty person/trainer rust on the top tube cable guide areas. More pitting etc. than expected (in 2 cable guides, and 2 spots underside of the TT). Enough for me to probably ignore any similar condition bike in the future (I say that now but, you know). Moral - the rust in the picture you show - I think Evaporust would work well on that, possibly with paper towels. Or Naval Jelly.

First I mechanically removed quite a bit of rust, and did some targeted Naval Jelly with limited success. Next I tried wrapping with Evaporust paper towels, which worked but again was slow progress. I then did the Evaporust soak and it worked ok (2x4 trapezoid to soak each frame portion [other than seat tube which was pretty clean] with scrap wood pieces to fill voids to limit volume used about 1/2 gallon or maybe a little less)- I should have scrubbed it and re-inserted it over and over with the top tube spots, when I had it all out back to working on touch up, there was still rust under some black coating that the Evaporust left behind. Lesson learned. OA may have done better, not sure. One interesting note, the fork and seat stays had CRAZY amounts of black Evaporust solution coming out when I let it drain then rinsed out. Like seriously crazy given the volume. Wonder what's in there! (Did quite a bit of heat gun "drying" and then some frame saver). I ended up doing more mechanical removal and more longer duration Naval Jelly at the end to get as rust free as I could tell, with quite a bit of pitting. Initial coat in those pitted areas was with some Rust Reformer Rustoleum primer, then sanded smooth, and covered with touch up paint.

One day in 2024 when this is done (I kid, hopefully) I'll throw up a quick thread.


Naval Jelly - actually 2nd round after Evaporust soak, gave up trying to keep it off the paint, the Imron held up fine

Evaporust wrapping - after initial tries with Naval Jelly

Soaking Framework hack job

Top Tube Evaporust Soak