Originally Posted by JunkYardBike
One more question, McDave. Is it necessary to open rust bubbles that have formed under the paint, or will the oxalic acid find its way to the source, loosen it, and cause the paint to flake off easily when brushed? There's quite a bit of subterranean surface rust (for lack of a better term) that I would rather not attack with a wire brush or razor if the acid bath will do a cleaner job. Thanks for all your help.
On the one really bad frame I've tried so far I didn't bust open the bubbles until after pulling it out of the bath and there was clean bare metal underneath with a bit of white powder. Hit it with a scratchless scotchbrite pad (blue one from the grocery store) and it was ready for primer or touch-up paint (I actually treated the outside with Amsoil too as I didn't have time to paint. Will use a wax and grease remover before touching up later).
But next time I would go ahead and "pop" any bubbles then use the *scratchless* scotchbrite pad from time to time while it's soaking to help speed up the process. No need to use anything harsh like a brush, razor, or even steel wool. You're just wiping off a white powder that comes off easily.
Too bad about the chrome. I wouldn't give up on all of it though until giving the oxalic acid a chance. Some of it, like the headset, may be salvagable with some polishing.