Windshield for 1974 170

[Abattsw]

Wondering if anyone has experience with fabricating windshields.  When I restored my 170 several years ago I had to replace the windshield.  I ended up fabricating my own out of 1/4 in thick smoked acrylic. It look great at first, but after a year, it shows stress cracks in the corner radius' where I heated and bent the windshield.  Anybody have better luck with another material?  I was thinking of trying Polycarbonate this time...not sure if this will be better though.

[wingtime]

Acrylic is the way to go.  You have to heat the bend point with a nichrome wire in a heat box. The trick is getting the radius right and polishing the edges very smooth and poilished to prevent stress risers that lead to cracks.  Also any holes have to be drilled with a special drill bit for acrylic.  Same thing regualr drill bits bite in too hard leaving tiny cracks that will grow.  There is a way to dull a regular bit for use on acrylic. Again the edges of the holes have to be smooth to prevent cracking.

[Abattsw]

Thanks for the info.  Looks like I just need to refine my heating method.