Window Panes - Glass or Polycarbonate?

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Greg_Lewis
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Location: Fresno, CA

Re: Window Panes - Glass or Polycarbonate?

Post by Greg_Lewis » Fri Dec 07, 2018 11:49 am

sabin wrote:
Fri Dec 07, 2018 8:45 am
i buy picture frames at the Dollar Store.

Jim
^ ^ ^

Just did this two weeks ago. 8X10 @ a buck each. .050 thick.
Greg Lewis, Prop.
Eyeball Engineering — Home of the dull toolbit.
Our motto: "That looks about right."
Celebrating 30 years of turning perfectly good metal into bits of useless scrap.

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BigDumbDinosaur
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Re: Window Panes - Glass or Polycarbonate?

Post by BigDumbDinosaur » Fri Dec 07, 2018 12:13 pm

Gentlemen, some of you are interchangeably using the words "plastic," "plexiglass" and "polycarbonate," which is incorrect.

Plastic is a generic term for a wide variety of petroleum-derived products. Clear plastic is soft and generally makes for poor glazing.

Polycarbonate, familiar to many as the tradename Lexan®, is a somewhat-hard material used to glaze, among other things, Amtrak's passenger car windows. Polycarbonate has good impact resistance, as well as some heat and ultraviolet radiation resistance, but can be scratched or otherwise damaged by casual contact with abrasive matter. Polycarbonate is the material used to make automobile headlights.

Polymethyl methacrylate (PMMA), familiar to many as the tradenames Plexiglass®, Lucite® and others, is a type of thermoplastic with glass-like properties. Originally developed in the 1930s for use in aircraft windscreens, PMMA can be formulated to achieve good scratch resistance and high optical clarity, approaching that of glass. Scratch-resistance varies with formulation, but tends to be good with the cast versions of the PMMA.

I used cast PMMA in rod form to make the portholes for my F7. The material machines very well and with the use of some rubbing compound after machining, the finished pieces are glass-like in appearance.
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I'm a caterwauling curmudgeon. What's your excuse? ☻

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NP317
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Re: Window Panes - Glass or Polycarbonate?

Post by NP317 » Fri Dec 07, 2018 12:26 pm

I'm presently making the windows for my 90-ton Mikado.
I purchased a 2 ft. sq. piece of single-strength glass ($6.) Just cut it into the required window sizes yesterday.
I'm using adhesive-backed copper foil (from my stained-glass-window-making supplies) to represent the inner frame pieces, and then wrapping the edges to secure it all together. When painted, they look quite prototypical, and won't melt... Also, their total thickness is close to the steel cab wall thickness.
I plan to show this process as a continuation of my Build Log.
~RN

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Marty_Knox
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Re: Window Panes - Glass or Polycarbonate?

Post by Marty_Knox » Fri Dec 07, 2018 4:10 pm

I use the cover plates from my welding helmets. They are.040"thick x 4 1/2" x 5 1/4". They are heat resistant, slightly flexible, can be cut with shears or scissors, cost about $1.40 each. The best thing is I didn't have to go anywhere to get them, just take one off the shelf.

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NP317
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Location: Northern Oregon

Re: Window Panes - Glass or Polycarbonate?

Post by NP317 » Sat Dec 08, 2018 12:55 am

Great idea!
~RN

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