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Mine is aluminium on aluminium so I assume it's worse off than carbon/alu etc.
Im going to buy some drain cleaner tomorrow to see if that works, if not its caustic soda. (Which may kill my frame too though)
Josh-
Maybe unrelated, but I eventually removed a bb (steel) from it’s shell (alu) by dosing it regularly over weeks with WD40 (I know there’s better products out there, but it’s generally good enough) and periodically giving it a try. One day it just let go.
Now my bud who owns the frame decides he has other plans... -
Mine is aluminium on aluminium so I assume it's worse
Definitely the worst of all possible worlds. Don't even think about chemistry, you'll either have no effect or you'll destroy the frame first as it has the thinner walls.
The seat post is toast if you want to save the frame. Depending on how far gone it is, the frame might be toast too. What you need to do is machine away the seat post from the inside out. The "big machine" method is a horizontal boring mill. Since the seat post is round and straight, it would be a fairly easy set up to get the frame on the table with the seat post coaxial with the spindle, the main caveat being to remind the machinist just how thin the wall of the tube is before he puts too much gronk on the workholding solution. Once you have it held in the right place relative to the tool, it's just a matter of taking light cuts with a boring bar until the hole is the same diameter as the seat post was. If you're left with a shiny bare metal bore, you've won. If there's still a fair bit of powdery crap in the bore before you break through to actual seat tube metal, you've just wasted your time 🙂
withered_preacher
gbj_tester
I remember watching this video on the same issue of a stuck seatpost: (great build btw)
https://www.youtube.com/watch?v=Kc37Ab8B580