Seatpost From Hell

I've never run into a seatpost seized this badly into a frame before. It was a beautiful SR fluted aluminum post stuck in a steel bike frame. The post was inserted most of the way into the frame without any grease (the previous owner might have even used epoxy glue for all I know). I tried every method I could think of: sticking the post in a bench vise, putting an adjustable wrench on the clamp and standing on it, soaking it for days in ammonia, penetrating oil, rust remover. I even used a propane torch to heat it up and then rapidly cool it in a bucket of water over and over again to see if that would break the corrosion. Nothing worked. After several days with two people fighting with it this was the result:

The top of the seatpost eventually broke off. The post was a solid casting, and really strong. I really wish I didn't break it. Next I tried the hacksaw method. I drilled a 5/8th" hole to get started:

The most tedious hour of my life:

After using a hammer and chisel:

Found a bigger drill bit:

Leftover shavings:

Vise time, maybe it'll work?

Darn. There's just way too much seatpost left in the frame to remove it. My last resort was to use lye to dissolve the aluminum (warning lye is extremely dangerous, don't touch it, breath it, stare at it for more than 8 seconds etc. Wear rubber gloves, eye protection, body armor, oxygen mask, fire suit etc.). After 2 days the seatpost is still intact. I was expecting it to dissolve rather quickly but it looks like it's going to take another week to remove.

Edit- Here's the post after soaking in lye for 4 days:

I managed to pry out the top 2 inches, but there's still a small collar left deeper in the frame:

Time for more lye. I've been sealing the top of the seat tube lug with a cork and pouring the lye in through the bottom bracket shell. So far it's working very slowly, but at least it's working. The post gets thinner every day. You can also see the damage to the seat clamp from all my hammering and prying to get the post out. I hope that it will bend back into shape later.

Edit- I finally got the rest of the seatpost out after soaking it for 5 days. The lye made the remaining piece thin enough that I could pry it out with a hammer and a thin screwdriver. Here's my trophy:

 

I learned a few things during this process. The hacksaw method works best on a thin seatpost that's not very deep inside the frame. Ammonia is useless. Spreading the seat clamp lugs will only damage the frame. In my case (thick seatpost set deeply into the frame) the only good way to remove the post would be to clamp the frame in a secure stand and drill it out with a 1" drill bit. The lye was a good second choice since I don't have a large enough drill bit, but it's messy, slow, and damaged the paint on the frame. I'm off to find a new seatpost now, cheers.