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| Plastic windows instead of real glass? http://www.rypn.org/forums/viewtopic.php?f=1&t=29909 |
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| Author: | robertmacdowell [ Mon Aug 09, 2010 10:31 am ] |
| Post subject: | Plastic windows instead of real glass? |
What workable options are there for window glass other than glass itself? I'm talking historic cars where full-thickness FRA glazing is not required and is not an option. What is FRA glazing made out of? My understanding is plexiglass is just junk, and polycarbonate is fairly expensive. My goals are being rock resistant, not fogging up and being miserable to look through, and being scratch-resistant vis-a-vis random brush and incidental use. I know intentional scratch vandalism is hard to stop. What have people used that has worked well? |
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| Author: | HOD Bill [ Mon Aug 09, 2010 12:49 pm ] |
| Post subject: | Re: Plastic windows instead of real glass? |
We are presently having windows of automobile windshield glass made for a car. While not super cheap, its cheaper than most alternatives and is more durable thank plexiglas. Check with a glass shop in your area. Bill |
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| Author: | Alexander D. Mitchell IV [ Mon Aug 09, 2010 12:54 pm ] |
| Post subject: | Re: Plastic windows instead of real glass? |
I think the answer to your/our dreams involves an element called "unobtanium." The only technique I've seen that came close to working was a sheet of expendable, cheap plastic mounted atop the regulation glazing, with enough of a gap that thrown rocks don't smash the glass. Eventually the plastic fogs, but you just replace it. |
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| Author: | Al Stangenberger [ Mon Aug 09, 2010 1:20 pm ] |
| Post subject: | Re: Plastic windows instead of real glass? |
robertmacdowell wrote: I know intentional scratch vandalism is hard to stop. AC Transit (Oakland CA area) buses have a thin sheet of expendable plastic mounted on the inside of each window to reduce scratch vandalism damage. |
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| Author: | MEC_557 [ Mon Aug 09, 2010 5:58 pm ] |
| Post subject: | Re: Plastic windows instead of real glass? |
Keep in mind that if you use any plastic product and set it in a channel to leave some space (make it smaller by 1/8" or slightly more). Plastic will expand and contract with temp changes and will buckle and/or damage the channel it's set in. This also presents a problem when using glazing compound as it will move. I have yet to hear of any long term success glazing large plastic panels in window frames or doors. If anyone has please speak up and tell us what you did. |
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| Author: | Dennis Storzek [ Mon Aug 09, 2010 6:46 pm ] |
| Post subject: | Re: Plastic windows instead of real glass? |
Shouldn't be a problem if these are railroad car windows glazed with "glass bead" molding screwed or nailed in place, cut the panel a bit scant and set in a small bead of silicone caulk against the fixed edge. I don't know of too many railroad cars with glass set in putty; that's chicken coop work. Plexiglass is hardly any more break resistant than plain old window glass; hit it with a rock and it will break, push on it hard and a crack will run from the saw cut chips at the edge. Lexan (polycarbonate) is almost bullet proof (it is bullet proof, in thick enough sheets) but scratches easily, although if you don't run the cars through a rotary brush car washer, this may not be a problem. When I worked for the Chicago Transit Authority in the seventies and eighties (building maintenance), we essentially stopped using glass, and replaced all breakage with one of the scratch resistant polycarbonate products, Tufack and Marguard are two trade names I remember, but haven't had to look for recently. This was polycarbonate with a thin coating of polyester (Mylar) applied to each surface, and it seemed to hold up well. I've seen a 2' square sheet of .200" sheet stop a two gallon fire extinguisher thrown at the ticket agent; it just bounced off, although it left a scuff. Biggest complaint is that if the wood sash were of questionable condition, glazing with polycarbonate would guarantee the sash would break the next time something was thrown at the window, but after all the questionable sash were replaced, the glazing held up pretty well. The other alternative would be tempered glass, this has to saw cut to size by a glass shop (this is likely the "automotive glass" someone mentioned). This isn't cheap, either. It is pretty resistant to rock strikes, but a bullet will crack the entire pane into little crumbs, rather than just make a hole, and the crumbs may also blow out of the opening. A kid with a .22 can cost a lot of money where tempered glass is used. |
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| Author: | RCman2626 [ Mon Aug 09, 2010 6:52 pm ] |
| Post subject: | Re: Plastic windows instead of real glass? |
Real FRA Type I and II glass is made out of Lexan glazed with a product called Margard made by GE. The material is extremely impact resistant and required for all Class I passenger equipment. It is also extremely expensive. Our windows in our coaches have this from the 1960s. They are 7/16" think with beveled edges. The biggest problem is when the Margard coating wears off, the windows immediately go foggy. Lexan cannot withstand UV rays and acid rain at all. |
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| Author: | Termite7 [ Mon Aug 09, 2010 7:05 pm ] |
| Post subject: | Re: Plastic windows instead of real glass? |
We put some Lexan on our church windows to protect the stained glass a number of years ago. It is several years old and still looks like new. The man at the glass shop told me it will not break and it will not scratch...and it has done neither. We could also cut it with a jigsaw and it cut like butter. It did cost a smidge more then the plexi but it is worth it. T7 |
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| Author: | Catalpa [ Mon Aug 09, 2010 9:22 pm ] |
| Post subject: | Re: Plastic windows instead of real glass? |
FRA Type 1 and Type 2 glazing is manufactured to meet certain strength requirements, found in Appendix A of 49 CFR 223. Certain polycarbonates, such as the ones previously mentioned and certain laminated glass assemblies are manufactured to meet those specifications. Test specifications are fairly specific including, for instance in the Type 1 standards, that there be no penetration of the back surface of the glazing by a 22 caliber long rifle lead bullet, of 40 grains in weight, traveling at a minimum of 960 fps. Also, there is a dropp test of 8 x 8 x 16 cinder block, meeting ASTM specifications, which is dropped from a height so that the block impacts at a rate of 12 fps, landing on it's corner in the center of the test glazing sample. Reputable manufacturers will provide certification of their product meeting Section 223 standards. Others on the board might be able to comment more extensively, however don't get the idea that any laminated glass or plastic (polycarbonate) product meets the FRA standards. Just because it's approved for a bus, truck, RV or car doesn't mean it necessarily is OK for purposes of Section 223. The AARPCO and RPCA ()car ownders associations are a potential source of information about compliant glazing, and waivers, for that matter. I know they are working together and are in contact with the FRA over this matter. |
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| Author: | ctjacks [ Tue Aug 10, 2010 11:49 am ] |
| Post subject: | Re: Plastic windows instead of real glass? |
Keep in mind that the FRA now interprets "historic" as cars built before 1945 when it comes to window glazing. If your car was built after 1945 it has to have glazing stamped FRA Type II in it or it doesn't comply with the rules. It doesn't matter if the glazing in the car is only a month old, or if it can stop rockets, or if it was installed by Amtrak when they owned the car. If your car was built after 1945, and it isn't going to be a static display, you will eventually have to comply with this rule. Chris Jacks. |
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| Author: | Les Beckman [ Tue Aug 10, 2010 2:04 pm ] |
| Post subject: | Re: Plastic windows instead of real glass? |
ctjacks wrote: Keep in mind that the FRA now interprets "historic" as cars built before 1945 when it comes to window glazing. If your car was built after 1945 it has to have glazing stamped FRA Type II in it or it doesn't comply with the rules. It doesn't matter if the glazing in the car is only a month old, or if it can stop rockets, or if it was installed by Amtrak when they owned the car. If your car was built after 1945, and it isn't going to be a static display, you will eventually have to comply with this rule. Chris Jacks. Chris - Does this also apply to cabooses that a museum might use to carry passengers? Or are freight cars, including cabooses, exempt from this rule? Les |
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| Author: | Dennis Storzek [ Tue Aug 10, 2010 4:46 pm ] |
| Post subject: | Re: Plastic windows instead of real glass? |
They weren't exempt when they carried only employees, one reason why cabooses had so many windows plated over just before the end; sheet steel is definitely cheaper than FRA glazing. By the way, my comments above concerning using plastic break resistant glazing on buildings had nothing to do with FRA glazing, which the original poster said he didn't need. |
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| Author: | Clem [ Wed Aug 11, 2010 10:50 am ] |
| Post subject: | Re: Plastic windows instead of real glass? |
RCman2626 wrote: Real FRA Type I and II glass is made out of Lexan glazed with a product called Margard made by GE. I would not use Margard. While it meets CFR standards, it gets hazy and dingy looking after a few years. |
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| Author: | ctjacks [ Wed Aug 11, 2010 11:21 am ] |
| Post subject: | Re: Plastic windows instead of real glass? |
> Does this also apply to cabooses that a museum might use to carry passengers? Or are freight cars, including cabooses, exempt from this rule? I can't speak authoritatively on this topic, but I can say that at least one group that has applied for a waiver to this rule has listed their caboose in the request, along with their passenger cars. Chris. |
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| Author: | hamster [ Wed Aug 11, 2010 10:34 pm ] |
| Post subject: | Re: Plastic windows instead of real glass? |
At Minnesota Transportation Museum we are constructing new wooden windows for our 1929 CB&Q NE-10 caboose that will be used for rides around our yard trackage. In the last major shopping of these cabooses in the 1960's or 70's the original wooden double hung-style windows were replaced with fixed aluminum sashes. We suspect that the original glass was double strength window glass. Our plan is to use safety glass. |
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