Re: [PSUBS-MAILIST] Viewport Toughness

[Warren Greenway <opensourcesub@yahoo.com>]

Acrylic is as bad as glass when it comes to
shattering.
Acrylic was chosen for viewports originally because it
was so much easier to form then glass. Acrylic
fatigues,
and is very likely to shatter like glass under
pressure
if you have a scratch or nick in it. I went over this
with an experienced plastics engineer, he also said
that the plastic shouldn't be used without annealing
(heat-treating).

Warren.

--- Brian Cox <ojaibees@ojai.net> wrote:
> I have a question about using a glass dome, wouldn't
> a thick glass dome actually stronger than acrylic? 
> But it would not be able to be used because of it
> propensity to shatter under certain types of
> stresses.    Adam ?
> 
> Brian Cox
>  
> ----- Original Message ----- 
> From: "Adam Lawrence" <adteleka@in-tch.com>
> To: <personal_submersibles@psubs.org>
> Sent: Monday, October 06, 2003 7:30 AM
> Subject: Re: [PSUBS-MAILIST] Viewport Toughness
> 
> 
> > From what I have read, when a viewport breaks it
> starts by extruding itself
> > into the flange and then final failure is like a
> shotgun going off. Also,
> > failure initiates on the inside surface, where the
> acrylic is in tension.
> > Test it, that's the only way you'll know!
> > 
> > Adam
> > 
> > 
> > ----- Original Message -----
> > From: "pierre&marie" <poulin.carrier@videotron.ca>
> > To: <personal_submersibles@psubs.org>
> > Sent: Monday, October 06, 2003 5:49 AM
> > Subject: [PSUBS-MAILIST] Viewport Toughness
> > 
> > 
> > > Hi People!
> > >
> > > I've been to a house building show here in cold
> Canada and there was a
> > boot
> > > that sold "unbreakable" windows for thief.
> > >
> > > They say that there technologie can change a
> normal window into a bullet
> > > proof window.
> > >
> > > The basic of that method is to put a high
> resistance thin plastic film
> > that
> > > stick on the window. Almost like a windshield.
> You should see me comming
> > > from now... I asked if we can put that film on
> acrylic and the said yes.
> > >
> > > Do you think that this could be helpful for
> psubs? It would not augment to
> > > strenght of the viewport but if it break it
> could prevent water from
> > comming
> > > inside the sub or prevent the viewport from
> imploding?
> > >
> > > Comments?
> > >
> > > Pierre "Viewport Strenghtener Technicien" Poulin
> > >
> > 
> > 
> 


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