Re: Modeling air hoses on STMFC era car


Jim Betz
 

Hi again,

I don't want to start a long 'argument' ... but I feel I have
to say what it is that I know (or think I know) that relates to
the color of the brake hoses, the glad hands, and the angle
cocks.

****

If my observations are correct the way that the air hoses
work is that the end of the air hose has a rubber grommet
(doughnut) in a cavity in the glad hand. And the other
glad hand has one also. And the two are compressed to
each other during the coupling up of the hoses in such a
way that the rubber grommets form the seal and the
hole in the grommet allows the air to flow thru the hose
coupling.
My recollection/observation is that the glad hand is a
cast metal piece - possible with some milling to form
the grommet cavity and the faces of the 'lock' that holds
them together. Definitely "no moving parts". You 'simply'
bend/twist the joint to make/break the coupling and the
casting of the metal forms the 'lock'.

I always have thought/assumed that the glad hand was
'just' cast iron/steel. And therefore the rusting of the
exposed surfaces is guaranteed by time. But the part of
the glad hand that the grommet contacts is kept smooth/
clean enough by the pressure/contact/compression of the
rubber grommet that it forms the seal.

I do not know what kind of metal is/was used on the
glad hands. Not sure I really care. They are probably
more than one kind of metal depending upon the
manufacturer and/or era.

Same is true for the angle cocks. The only part of them
that needs to be clean is the internal part that is the
actual valve. I would not be at all surprised to learn
that in the era of this list they were usually either
cast brass or cast galvanized. With some machined
surfaces/parts. And, since they activated with a 90-degree
turn they were most certainly a ball valve of some sort.

****

My observation/experience is that both are "always"
dirty/rusty in color (some shade of brown/tuscan/whatever
you want to call it). Perhaps they started out as galvanized
but they quickly got "too dirty to tell".

The hoses usually started out as black but a few were
red ... and they both got essentially grimy black quickly.

- Jim Betz

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