OK, here goes, hope someone can help ...
step 1, usual trick just try to rotate the seat post (with some WD40) to get it free. Then used a sacrificial seat, with a tyre iron for more leverage (jammed under the seat)
step 2, try more wd40, including trying to pry seat post apart with big screwdriver
step 3, turn it upside down, remove BB, fill with coke (kid friendly alternative to ammonia to dissolve the steel/alu oxide weld ... my workshop is in the garage which is used a lot by the family). Leave for 3 days to soak through
step 4, I don't have a vice, but managed to hold the sacrificial seat in my workbench, then held on to forks & tried to rotate ... no luck
step 5, repeat step 4 after cooling the post down in ice (in theory the alu seat post should shrink more than the steel frame (?), but the temperature difference at 0C compared to room temp was just not enough)
step 6, (probably not a good idea), tried to "encourage" it out with a hammer
no success so far ... some more extreme things are needed (dry ice, chemicals, good strong bench vice ...), but at this point I some help from someone with experience would be good ...
step 1, usual trick just try to rotate the seat post (with some WD40) to get it free. Then used a sacrificial seat, with a tyre iron for more leverage (jammed under the seat)
step 2, try more wd40, including trying to pry seat post apart with big screwdriver
step 3, turn it upside down, remove BB, fill with coke (kid friendly alternative to ammonia to dissolve the steel/alu oxide weld ... my workshop is in the garage which is used a lot by the family). Leave for 3 days to soak through
step 4, I don't have a vice, but managed to hold the sacrificial seat in my workbench, then held on to forks & tried to rotate ... no luck
step 5, repeat step 4 after cooling the post down in ice (in theory the alu seat post should shrink more than the steel frame (?), but the temperature difference at 0C compared to room temp was just not enough)
step 6, (probably not a good idea), tried to "encourage" it out with a hammer
no success so far ... some more extreme things are needed (dry ice, chemicals, good strong bench vice ...), but at this point I some help from someone with experience would be good ...