7th) It will gas, smoke, bubble and gurgle all the time it is acting and working, so once it isn't doing it so much then that means there's not a lot of aluminium left.
8th) After about the 3rd jugful I thought I'd see how it was doing and twisted the top of the seat post off which left a very thin seat post remnant inside the seat tube, this still wouldn't come out even though it was no more than about half a mill in wall thickness and I tried to peel it down the inside of the seat tube using a mallet and big flat screwdriver.
9th) after the 6th jug full what I was finally left with was a small bit of tin foil that finally came out.
So success, it took a while, made a big fuss about it and made a big mess but ultimately it worked and I'd happily do it again if I needed to.
And lastly, remember safety first, its nasty stuff and only use this method on aluminium set posts that are stuck in steel frames, anything else will go very badly wrong.
8th) After about the 3rd jugful I thought I'd see how it was doing and twisted the top of the seat post off which left a very thin seat post remnant inside the seat tube, this still wouldn't come out even though it was no more than about half a mill in wall thickness and I tried to peel it down the inside of the seat tube using a mallet and big flat screwdriver.
9th) after the 6th jug full what I was finally left with was a small bit of tin foil that finally came out.
So success, it took a while, made a big fuss about it and made a big mess but ultimately it worked and I'd happily do it again if I needed to.
And lastly, remember safety first, its nasty stuff and only use this method on aluminium set posts that are stuck in steel frames, anything else will go very badly wrong.