On Fri, 4 Aug 2017 01:10:24 -0000 (UTC), bob prohaska
wrote:

In searching for methods to free an aluminum steering stem
from a steel bicycle fork the ideas of using either auto
antifreeze or aqua ammonia have come up. I think the antifreeze
idea is a leftover from the days before aluminum radiators, but
haven't been able to confirm it. The aqua ammonia idea seems
consistent with the chemistry (NH4OH attacks Al(OH)3) but
nobody seems to have any substantive accounts, either of success
or failure.

Does anybody on this group have experience with either method
they'll share?

Thanks for reading!

bob prohaska



There are a number of you tube videos showing the use of lye to
dissolve a aluminum seat post in a steel bicycle frame.

My own experience has been that if dosing with some sort of
penetrating fluid for a few days and a long wrench won't move it that
the lye is probably the best solution as if the aluminum part has been
in the steel tube for a number of years, as bicycle parts often are,
they become almost welded together with corrosion.

--
Cheers,

John B.