Oxalic Acid works like magic to remove rust, but it does nothing to stop or slow down the process. So, if your worry is that your bike will continue to rust and become comprimised, then this is the wrong solution. Think of oxalic acid as a cosmetic solution.

If you want to lengthen the life span of your frame, you can just leave the rust in there and douse it completely with something that might do something to keep some air and water from reacting with the steel. Framesaver, of course, is made for this. Even WD-40 seems like it would do something.

jim