Wow... my first new thread in quite some time.
As some of you may remember, I have an old Burley tandem with a frozen seatpost. I've tried so many ways to un-freeze this thing I don't even know why I care anymore. And my most recent attempt is based on oxalic acid. As all discussions go on the subject, it's said that OA will dissolve aluminum, so I figured why not try.
Well, I mixed a 10% blend (1oz OA to 9oz of water [seat tubes don't hold a lot]) and after a week I mainly have a yellow goo on the inside of it. So... Either I used to strong of a mixture, I need re-mix it/flush it more often, I need to use a heavier mixture, or my efforts are misguided.
Keep in mind I have tried everything short of reaming the tube out, twisting heavily, sawing out the inside, ammonia... I mean, this was my last ditch effort. If this doesn't work I'm gonna have to talk to a machine shop, and if it gets that bad I may just have to re-evaluate with my girlfriend if it's even worth it.
So... Any input?