Weekend Photos -- 3-27-2020

[rogruth]

Wayne,
Will your auto-rack make it around your layout alone?
Or anyway? With a loco or not?

[webenda]

Wayne,
All very interesting but I don't see a GG1. I see an Alco type road switcher. I think. ??? Maybe the heat got to it.

Roger, Dark green with gold striping, back of the loop just ahead of the red 2817 caboose.

Wayne, you need a tunnel for the layout.

Healey

OK. Hard for me to see.
The Alco looks as if it is on a flatcar.

Yes, Alco is actually a baby EMD GP7 shell is on a flatcar.
Here is a closer look at the GG-1 (I apologize, it did not enlarge very well.)


A tunnel Healey? The straight track is only 14 inches long. The Lionel AC12 hasn't even got itself back together before it reaches the next turn. The AutoRack overhangs the roadbed even on the straight section.

[webenda]

Wayne,
Will your auto-rack make it around your layout alone?
Or anyway? With a loco or not?

No. It will sit on the curve with flanges inside the rails but it won't move without derailing.

[rogruth]

Wayne,
Will your auto-rack make it around your layout alone?
Or anyway? With a loco or not?

No. It will sit on the curve with flanges inside the rails but it won't move without derailing.

Darn! I thought that would just look cool/weird.

[webenda]

So did I.

And that one is a shorty, only 22.4 inches long. Some of the newer cars, built by Gunderson (a subsidiary of The Greenbrier Companies) measure 145 ft 4 in (44.3 m) long and 20 ft 2 in (6.15 m) tall. That is 36 inches long in O scale.

[MYmoo]

... The trains and roadbed are made of ABS plastic, which has no melting point.
ABS becomes soft at 221 °F and continues getting softer until 446 °F where it flows as a liquid. ...

Wayne,

These two statements seem to be contradictory. Can you
please explain how a substance is not melted when it is in a
liquid state?

Thank you for making it clearer to me.

[J. S. Bach]

... The trains and roadbed are made of ABS plastic, which has no melting point.
ABS becomes soft at 221 °F and continues getting softer until 446 °F where it flows as a liquid. ...

Wayne,
These two statements seem to be contradictory. Can you please explain how a substance is not melted when it is in a liquid state?
Thank you for making it clearer to me.

I think that I understand what he is saying; ice turns to water at a specific temperature (32°) whereas AB slowly turns into a liquid over a range of increasing temperature.

[MYmoo]

... The trains and roadbed are made of ABS plastic, which has no melting point.
ABS becomes soft at 221 °F and continues getting softer until 446 °F where it flows as a liquid. ...

Wayne,
These two statements seem to be contradictory. Can you please explain how a substance is not melted when it is in a liquid state?
Thank you for making it clearer to me.

I think that I understand what he is saying; ice turns to water at a specific temperature (32°) whereas AB slowly turns into a liquid over a range of increasing temperature.

Thank you for your response.

(ABS (and many other) plastics melt quickly with the heat of
a soldering gun).

Speed of liquficaion will depend upon speed of temp. rise,
(but you already knew that).

[webenda]

... The trains and roadbed are made of ABS plastic, which has no melting point.
ABS becomes soft at 221 °F and continues getting softer until 446 °F where it flows as a liquid. ...

Wayne,
These two statements seem to be contradictory. Can you please explain how a substance is not melted when it is in a liquid state?
Thank you for making it clearer to me.

I think that I understand what he is saying; ice turns to water at a specific temperature (32°) whereas AB slowly turns into a liquid over a range of increasing temperature.

Dave understands perfectly.

Mixtures: Ethylene glycol freezes at 10 °F. Water freezes at 32 °F. A mixture of 60% ethylene glycol and 40% water freezes at −49 °F.

ABS is a mixture of acrylonitrile, butadiene and styrene.
Acrylonitrile has a melting point of −119 °F (It is a liquid at room temperature.)
Butadiene has a melting point of -164 °F (It is a liquid at room temperature.)
Styrene has a melting point of −22 °F (It is a liquid at room temperature.)*

Mix these three liquids together and... polymerization. The molecules of the three liquids combine to form larger molecules that are solid at room temperature (i.e. 68 °F.)

When substances made of small molecules (acrylonitrile, butadiene, styrene) are heated, they simply melt and form a free-flowing liquid; however with polymers the process is more complex. When heated, the polymers will first become flexible before melting. This is due to their structure. In some polymers, there are areas of crystalline and amorphous** regions. When the solid material is heated, the polymer chains will reach a temperature at which they can move relative to each other. On further heating of the polymer, it becomes flexible and shows the more conventional properties expected of a plastic, that is it can be formed into different shapes without breaking. It flows like a liquid into the different shape yet retains that shape when the force that caused the flow is removed. Eventually, if the polymer is heated enough, the melting temperature will be reached and the plastic becomes a viscous fluid that will not hold any shape. In reaching the melting temperature ABS plastic has gone through a range of temperatures, starting at 221 °F, where it will flow like a liquid if enough force is applied to it to 446 °F where it will not hold a shape. It is considered liquid when it will no longer hold a shape. There was no "melting point" where it suddenly changed from solid to liquid.


*The plastic we know as "styrene" is more properly called "polystrene." Although the names sound familiar and may be confusing, styrene and polystyrene are different and have completely different properties. Polystyrene is produced by free radical vinyl polymerization, from the monomer styrene. See:=> https://pslc.ws/macrog/radical.htm for a simple explanation of how polystyrene is made.

**Amorphous: without a clearly defined shape or form.

[MYmoo]

... The trains and roadbed are made of ABS plastic, which has no melting point.
ABS becomes soft at 221 °F and continues getting softer until 446 °F where it flows as a liquid. ...

Wayne,

These two statements seem to be contradictory. Can you
please explain how a substance is not melted when it is in a
liquid state?

Thank you for making it clearer to me.

I was unaware that ethylene glycol freezes at 10 °F.

This would help explain why all the 'unmixed' 'antifreeze'
I've had occasion to use never froze when stored at
temperatures well below 0°C.

It must have been all the rust inhibitors and other
'additives' added to the 'mixture', that prevented the
solidification.

IOW, it wasn't pure in heart and soul.

Thank you, again, for the clarification, and the "nudge, nudge" ,
that I should have spent more time in my High School chemestry class on the subject matter
than on the physical shape of my attractive female instructor...

[Roy]

I had a Seaview model I built from a kit, which distorted from the sun on my window sill. I also lost a slot car set I was selling outdoors, for the same reason. I think both were made from what was called "high impact styrene". It's amazing how perishable that stuff is, yet the garbage floating in the Pacific won't die.

[rogruth]

Myron,
At least you have some kind of excuse.
In gades 1-12 I never had an attractive female instructor.
The males didn't interest me either.
There were plenty of attractive female students to divert
my interest from academic topics.