On Tuesday, February 14, 2012 5:11:22 AM UTC-8, Leon wrote:

That cool air hitting the warm iron results in almost instant
condensation on the iron.

BUT a few years ago Swingman and I were working in his shop, it had
been quite warm. We had a cold front blow in suddenly at the end of
the day and the temperature dropped quickly. "Heavy" Condensation
formed on the iron machine surfaces with in minutes, something we do
not often see.

Why? I have no idea.

Did you have the windows open, it got cold (and the iron cooled down),
then you shut the windows and opened the doors to the rest of the humid,
warm house?


No windows, detached uninsulated garage, just a 16' garage door that had
been open all day and a rear side door that was open for the 3' fan to
create a breeze through the shop. At the end of the day the front blew
in and almost immediately, 10 minutes, "puddles" ow water formed on the
cast iron surfaces. I started wiping the water off of the first casulty,
;~) before Swingman noticed what was happening, he was still finishing
up with something on the TS. We both had to stop what we were doing to
wipe the surfaces off.

Now the iron might have gotten cold but this all happened in a matter of
a few minutes and the the whole shop cooled down before closing the doors.

It all was a bit freaky, I had never seen condensation form that quickly
in such a great quantity.



On Tuesday, February 14, 2012 5:11:22 AM UTC-8, Leon wrote:
On 2/14/2012 6:54 AM, Han wrote:
Leonlcb11211@swbelldotnet wrote in
:

On 2/13/2012 7:50 AM, Leon wrote:
On 2/13/2012 7:12 AM, Han wrote:
Leonlcb11211@swbelldotnet wrote in
:

That cool air hitting the warm iron results in almost instant
condensation on the iron.

Generally, warm and moist air hitting a cool surface is what cuases
condensation on the cool object. Cool air hitting a warm surface
does NOT give condensation.


Bull ****!

Sorry Han, To explain my response, and where I have witnessed your
second statement being not true "all of the time" is in Swingman's
shop.

I understand how the condensation principal works.

BUT a few years ago Swingman and I were working in his shop, it had
been quite warm. We had a cold front blow in suddenly at the end of
the day and the temperature dropped quickly. "Heavy" Condensation
formed on the iron machine surfaces with in minutes, something we do
not often see.

No windows, detached uninsulated garage, just a 16' garage door that had
been open all day and a rear side door that was open for the 3' fan to
create a breeze through the shop. At the end of the day the front blew
in and almost immediately, 10 minutes, "puddles" ow water formed on the
cast iron surfaces. I started wiping the water off of the first casulty,

It all was a bit freaky, I had never seen condensation form that quickly
in such a great quantity.

There was probably an abrupt change in air pressure (if air at high relative
humidity expands, its density goes down BUT the relative humidity goes
up). The result is that your ambient air in the shop was instantly
supersaturated, and the first nucleation site it found was on the iron.
Once the water film was established, the whole wet surface was a
fast growing dewdrop. Getting a dewdrop started (from near-zero
diameter), is energetically hard because of the surface tension that
acts to diminish the dewdrop diameter and return moisture to the
surrounding air. Waxing the iron makes the nucleation sites hydrophobic,
thus the dewdrop has to create the whole spherical surface
against surface tension.

There needn't be any important temperature change involved, in condensation.