**** kroil, and torches and ammonia. Put away the hacksaw and never sweat again with a stuck seatpost. I'll document this next time I do it and make nice photos.

This is really only useful for aluminum seatposts stuck in steel frames... the lye didn't seem to do much to the paint, but if you make your solution to strong I reckon it might dissolve the paint, so be careful, or tape over the frame with something that'll protect it.

Go to the hardware store and buy lye crystals, good rubber gloves and some safety goggles/glasses

Make up a strong solution of lye. I used around a half cup in 5 litres. Use cold water to make your solution (ideally in a steel bucket) and add the crystals gradually while stirring **don't add water to the crystals**, this will cause the solution to get warm and start to bubble. Stir until the crystals are dissolved and the solution calms down. I was really lucky to have a bucket that had spouts on both ends so I could submerge the seat-tube deep enough. It's also possible to remove the BB and seal the seat tube from the bottom and pour some solution in, however it will foam all over the place and you'll have to constantly top it up.

After a day or so in the lye, the seatpost is usually completely dissolved. If it's not, it'll be mostly gone and you can usually tap it out with a small chisel and a soft tap with a hammer.

I used this on a friend's frame that was a winter bike exposed to salt and the seatpost resisted all the methods listed on Sheldon's page.

Heating up an aluminum seatpost will only cause it to expand and get "more" stuck... the aluminum will effectively wedge itself in there more... I don't understand how that benefits removal, but to each their own.

Seatposts get stuck because of galvanic corrosion, and to unstick them you need to destroy the chemical bonds... the lye will completely dissolve the seatpost, but it's worth it to save a good frame if you ask me.

This is also handy with seized stems in nice forks. If you want to save time you can cut the stem right close and drill out some of the aluminum if you're in a rush or short on lye.