"Winston" wrote in message
...
Ed Huntress wrote:
On Tue, 31 Jan 2012 06:07:14 -0800,
wrote:

So I cut off some one-foot test pieces of EMT and stood them up in a
plastic peanut butter jar, and poured muriatic acid around them to a
depth of xix inches or so. The galvanizing stripped off in minutes.

--Winston

The caustic soda (NaOH) in drain cleaner also removes zinc, without
affecting the steel. The CO2 in the air converts any lye you didn't remove
into washing (Na2CO3) or baking (NaHCO3) soda. All are mildly protective of
the steel, but not enough for outdoor use. You can see the difference
between the silvery zinc and greyish steel to tell when it's done.

Drain cleaner doesn't release any fumes to damage your lungs or machinery.
Spilled HCl can be more dangerous than other strong acids because it soaks
in rather than reacting immediately with the outer layer of dead skin.

jsw