Removing stuck or seized seatpost?

polybikeuser A while back I got some from the hardware store thats towards the Regent Street end of Brewer Street on the north side of the road, sorry for the slightly obscure street directions but I can't remember/never knew the name of the shop. I know someone said they thought the coca cola trick worked on the same principle as caustic soda as they're both base solutions but I'm pretty sure that coca cola is mega acidic, not basic and the chemistry of the caustic soda idea sounded more plausible. I personally would still go with the plusgas, but I wouldn't give up on the caustic soda just because coca cola didn't work.

Yeah, Coca Cola is acidic.

I would suggest concentration hydrochloric acid, that'll literally dissolve the seat post. But it'd probably mess your frame up a little bit.