Posted: 11/24/2009 9:46:34 PM EDT
| I was driving over Donner Pass this week after the snow and the road was sanded by Cal-Trans. After the 5 or 6th rocket smacked into the glass like a .22 air gun I was wondering if anyone makes a poly carb windshield? It would not crack like the glass laminate but am I missing something why it would not work? Not rigid enough or optical clarity? |
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They sell SpeedGlass windshields for Jeeps anything else would be a custom mold job, I do remember a guy doing a Blazer one himself on one of the 4x4 sites using a stock unit for the mold. |
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Durability. It would pit and craze rapidly. It is use in aircraft windscreens. This, most plastics dont like sunlight. Lots of drag cars and offroaders use Lexan pc and it works well but they usually dont sit in the sun for years either. There is plenty of PC that is baked in the sun for years and holds up just fine in regards to solar radiation. Bulletproof glass is PC sandwiched between glass. Many types of security windows are made from PC. The problem is in the use as a windshield, it is getting effectually sandblasted over the course of years. PC can't resist stratches and pitting like glass even with coatings. |
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Durability. It would pit and craze rapidly. It is use in aircraft windscreens. This, most plastics dont like sunlight. Lots of drag cars and offroaders use Lexan pc and it works well but they usually dont sit in the sun for years either. There is plenty of PC that is baked in the sun for years and holds up just fine in regards to solar radiation. Bulletproof glass is PC sandwiched between glass. Many types of security windows are made from PC. The problem is in the use as a windshield, it is getting effectually sandblasted over the course of years. PC can't resist stratches and pitting like glass even with coatings. As a glassblower I can tell you....all glass except Quartz glass blocks UV which is what causes the degradation of PC. This is why you don't get a suntan through your windshield when you drive. This is also why it doesn't degrade in your windshield. Interesting fact: Hospitals used to have Quartz windows in some rooms so the bedridden patients could actually get sunlight.....the windows were EXTREMELY expensive. |
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Quoted: Quoted: Quoted: Durability. It would pit and craze rapidly. It is use in aircraft windscreens. This, most plastics dont like sunlight. Lots of drag cars and offroaders use Lexan pc and it works well but they usually dont sit in the sun for years either. There is plenty of PC that is baked in the sun for years and holds up just fine in regards to solar radiation. Bulletproof glass is PC sandwiched between glass. Many types of security windows are made from PC. The problem is in the use as a windshield, it is getting effectually sandblasted over the course of years. PC can't resist stratches and pitting like glass even with coatings. I disagree PC left out in the sunlight will yellow in time, it doesnt matter how much UV inhibitor its is blended with, the same goes with most plastics. I agree on the scratching though adding windshield wipers to the mix doesnt help much. |
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Lexan turns yellow with sun exposure. You'd need to use (much weaker) acrylic if you wanted it to stay clear.
As to "why don't they"... I believe it has to do with federal car requirements. Laminated glass is required, front and rear. Other materials are not allowed. ~ |