Re: [PSUBS-MAILIST] polycarbonate vs acrylic pros cons and testing$

["Sean T. Stevenson" <cast55@telus.net>]

Eighth:  The index of refraction (IOR) of acrylic is closer to the IOR of 
water than polycarbonate is.  This means that an acrylic viewport will have 
less optical distortion than a comparable one made of polycarbonate.

-Sean


Quoting skrewgun007@aim.com:

>  Thank you most helpful. I do need to apologize for the fact that I
> accidentally dropped my sub testing under Franks poetic outlook. I read it
> and used it to send out my message without renaming the subject. does anyone
> else know of any poly test that have been done or have anything else. ohh
> yea, I asked my local glass man how much 1.5" acrylic ran and he told me $24
> a square foot. I don't know if he was right since he was guessing. what is a
> good rate on this material and where can I find 2" thick stock for my front
> view port? any on line suppliers. what do you mean to expensive. I figured
> you guys where made of money LOL just kidding.
>   
>  -----Original Message-----
>  From: empiricus@telus.net
>  To: personal_submersibles@psubs.org
>  Sent: Thu, 5 Oct 2006 2:15 AM
>  Subject: Re: [PSUBS-MAILIST]sinking....
>  
>   Hi there - I brought just that topic up a few months ago about
> polycarbonate vs. acrylic. Phil Nuytten was kind enough to give his two
> cents. I'm paraphrasing here.   First: Acrylic has been researched to the nth
> degree and is very predictable because of that research. The numbers are out
> there.   Second: It is more brittle, however, and in an ambient wet or dry
> sub my choice would be the polycarbonate simply because of collision, either
> with a falling anchor or a bump into a reef.   Third: Poly under pressure
> will creep apparently. That makes it unpredictable. Which way is it going to
> flow, etc. Bad news.   Forth: Poly is really really really expensive.  
> Fifth: Poly is stronger but scratches easier and is harder to get the
> scratches out (I think I've got this one right)   Sixth: They may have
> different UV light properties that exclude using one or the other depending
> on your mission statemtent.   Seventh: Failure with acrylic is often
> catastrophic, meaning it's sudden. I!
>   would imagine incipient creep with poly would give some indication of
> failure, especially with strain gauges attached.   Some pros, some cons. Hope
> this helps.   Rick L Vancouver    
>    
> ________________________________________________________________________
> Check Out the new free AIM(R) Mail -- 2 GB of storage and industry-leading
> spam and email virus protection.
> 







************************************************************************
************************************************************************
************************************************************************
The personal submersibles mailing list complies with the US Federal
CAN-SPAM Act of 2003.  Your email address appears in our database
because either you, or someone you know, requested you receive messages
from our organization.

If you want to be removed from this mailing list simply click on the
link below or send a blank email message to:
	removeme-personal_submersibles@psubs.org

Removal of your email address from this mailing list occurs by an
automated process and should be complete within five minutes of
our server receiving your request.

PSUBS.ORG
PO Box 311
Weare, NH  03281
603-529-1100
************************************************************************
************************************************************************
************************************************************************