JamesM
Senior Retro Guru
Chute55uk":3gbe7trs said:the ammonia will eat the alu seat post so what will it do with an alu frame?
I believe ammonia only eats the aluminium oxide but doesn't harm the aluminium itself. It's therefore safe to use on aluminium posts stuck in aluminium frames.
Caustic soda on the other hand disolves aluminium so is good if you want to remove an aluminium post from a steel frame and you aren't bothered about saving the post.