Good Evening Mark,
Thanks for the great data to chew on. My Great Uncle and his son had done all the research on strength comparison, so I was going off data from them. I'll have to do allot more reading, but that's all right mate, I'm still young. : )' There are a number of different brands and formulas of both polycarbonate and acrylic so I would expect some what different properties for each. There is also issues with UV resistance, clearity, krazing, resistance to cracking if hit at pressure in freezing weather, etc,. I don't remember the thickness of Hyzod they used but I think it was about 5/8" and it cost about $62 per 7" diameter view port. I'll have to call them and ask. Acrylic would of been cheaper but they liked some of the properties of the Hyzod.
Regards Brent
From: "Mark Roberts - Harbortronics" <Mark@Harbortronics.com>
Reply-To: personal_submersibles@psubs.org
To: <personal_submersibles@psubs.org>
Subject: Re: [PSUBS-MAILIST] Perry lockout
Date: Sun, 28 Jan 2007 20:34:30 -0800
Careful there.... polycarbonate has some attractive properties, but it is NOT stronger than acrylic (plexiglass)A quick check on a couple places...Compressive StrengthPolycarbonate 12000 PSIAcrylic Sheet 14500-17000 psiCast Acrylic 11000-19000 psiTensile StrengthPolycarbonate 9,500 PSIAcrylic Sheet 7980-12300 psiCast Acrylic 8000-11000 psiMark Roberts
The interior of this six person chamber was painted with a special epoxy paint, and when you use the chamber you must wear 100 percent cotton clothing with no dies in it to reduce the chance of electrostatic shock. You can see in this picture the intake and exhaust of the O2 as well as external lighting fixtures shining through the Hyzod view ports, now called Makrolon. The bulb in this light fixture is a screw in flouresant type to keep the heat down on the view port as well as the interior of the chamber.****************************************http://www.frappr.com/?a=viewphoto&id=2384531&pid=3842505&myphotos=1
Makrolon is used by NASA and it gives you allot more strength per thickness compared to plexiglass. I find it easier to have my view ports water jet cut.