I'm in the process of extracting what seems to be a galvanically welded SR LaPrade seatpost from an early 80's Univega Sportour frame. It's been slow going and very frustrating. After about four hours of hack-sawing, I now have the post cut into five slices vertically, but all I've managed to do from there is to break off the top inch or so of two of the five slices. Right now, I have the bottom of the seat tube corked, and the tube is filled with ammonia and soaking for a while. If this doesn't work, I guess lye will come next.
This is the post that used four vertical clamping plates with a square bolt running transversely through a short cylinder at the top of the post. There is one of this style on ebay right now. Mine looks about as short as the one listed, but I'm having difficulty getting a good view down the seattube. I've hooked what feels like the bottom of the post with a bent hacksaw blade, and it seems to be only about four inches into the seattube. Anyone know for sure? Did these come in longer lengths so that perhaps I just haven't cut deep enough down the seattube?
Also, when and if I get this sucker out, does anyone happen to know the diameter I need for the replacement? I've been assuming that a Univega of this vintage used 26.8, but this model is not in Sheldon Brown's database.