Plexi-- Cast or Extruded

[nassaw]

We're looking to put a windshield on a 40' cat. The plastic company recomends to use a cast sheet product. What would be the difference between cast and extruded besides the price.

TIA
Bob C.

[D'ARTOIS]

Depends entirely on the design of that windshield: Does it sport rounded corners or is it a flat job? There is the difference, if it has rounded corners you better cast it due to stresses that builds up in flat material (that is extruded) when you bend it.
There is more to it, but principally this might be the answer.

[Thunderhead19]

Absolutely depends on the design. Stresses can be relieved if you heat the plastic enough when you bend it. Bending stuff, as opposed to casting, can give poor optical quality. The plastic supplier is probably trying to give you exactly what you want at the lowest price. A cast part is cheaper than paying for the tooling for a custom extrusion, an extrusion might be cheaper if the tooling already exists, but that is almost never the case (unless you're prepared to make some modifications to make the existing extrusion fit).

[rxcomposite]

As i understand it, cast or extruded refers to the manufacturing process of the plexi glass. they come out the same in sheet form.

If that is the case, better ask the sales representative what he is selling and explain what you plan to do with the glass.

[nassaw]

Gentelman.
Thank you for all your help. My application is for a slight curve. We decided against the tight bend around the salon top because of cost. After re talking to the supplier they explained that we had to go with cast because they couldn't get the acrylite product tinted, extruded over 1/4 inch thick. I think they're B Sn me but there the only supplier in my area.
Thanks again
Bob C.

[UCJOHN]

www.updplastics.com can fabricate anything you want in any thickness and color. They also have many stock windshields for popular boats. Extruded material is not recomended for marine applications due to the extrusion process. The material has a much softer density to it then cast sheet. It is also much more sensitive to chemicals which cause crazing when it comes into contact with extruded material. Cost difference is not much. I have been a fabricator for 30 years and I learned the hard way when customers brought shield to me made by someone else in extruded material only to have to remake it again.