Windshield Replacement

[rcnight]

I was talking to a plastic supply house about material for a replacement windshield. It was mentioned that unless it was "cast", it would spiker crack just as mine is now. The salesperson couldn't elaborate on what "casting" was. I can only assume it would be similiar to metal casting. Anyone ever hear of this?

[RICHV]

Cast acrylic has a higher molecular weight than extruded acrylic. Extruded acrylic is extruded in a molten state between two precise spaced rollers and run down a belt system to allow the acrylic to cool down. The benefit for this is the cost process is lower. Cast acrylic is poured between two panes of glass that is spaced at the desired thickness. It is baked in a climate controlled oven and cooled down slowly.The process takes alot longer than the extrusion process and the price is usually about 50 percent higher. The reason the extrusion material crazes or as some people say gets small crakes in it faster than the cast acrylic is- The extruded acrylics molecules all run in the same direction and the cast acrylics molecules run in different directions giving the material the extra strength. By the way cast material has a better clarity to it than extruded. Also note that cast acrylic if you were looking at 1/4" material comes in two thicknesses- .220 and .236, so make sure you know which one you are getting! If you need the material call my shop and I can get you a price on it if you can't get a good price wherre you are
Tidewater Plastics 757-459-8031 Hope that answered your question- Rich

[rcnight]

Thanks for the lowdown on the differences. How much service time could you expect to get out of the extruded material? Is making a replacement windhield with the cast material out of reach for the do-it-yourself type? [img]/images/graemlins/smile.gif[/img]

[mdurfeeh]

RC, Let me know how you make out with this.My 72 seacraft windshield is original and has the same problem.