Re: [PSUBS-MAILIST] Acrylic laminating

["Dan H." <jmachine@adelphia.net>]

Why laminate at all?
If you want to machine the inside and outside anyway, why not start with a
thick sheet of acrylic, but instead of cutting it into rings, just heat it
in an oven for a while and draw it over, or into, a rough form of what you
want it to look like.  You could vacuum form it but if heated enough, it
will flow some on it's own.  Since your going to machine it after it's
formed, your pattern could be nothing more then a mound or pot shaped out of
plaster.  This way there will be no seams, it will take less material and
you could stress relieve it after machining.

Dan H.

----- Original Message -----
From: "Ray Keefer" <Ray.Keefer@Sun.COM>
To: <personal_submersibles@psubs.org>
Sent: Thursday, January 15, 2004 12:41 PM
Subject: Re: [PSUBS-MAILIST] Acrylic laminating


> Hi Pierre,
>
> What little I remember back to my days in a platic fabrication shop.
> 15+ years ago.
>
> The chemical was called MDC (I think). The stuff is not only volitile but
> carciongenic. Wear latex/rubber gloves and avoid all skin exposure. Do not
breath.
>
> We used syringes with the tips of the needles broken off to squirt the
stuff between acrylic pieces to be glued. Place the two pieces of material
together then squirt the MDC along the edge. The wicking action will pull
the MDC in and will set in 3 or 4 seconds.
>
> As I recall, MDC never totally distributed evenly. There were spots that
did not get the glued. Which was fine for the applications we were using it
for. Also MDC was clear so no ugly residue spoiling the looks of clear
acrylic. You had to look closely to notice where it never wicked to.
>
> My concern for your application is two fold:
>
> 1. Is the boundry layer where the MDC is applied just as strong as the
surrounding acrylic or weaker? If weaker then you have a failure point.
>
> 2. Uneven distribution of MDC could leave the material left after the
machining weak or even unglued.
>
> The upside is that you are making an ambient pressure sub so the stresses
on the dome would not be neary as great as with a 1 ATM sub.
>
> Any good plastic shop can tell you the name of what they currently use. On
the web you could try Tap Plastics (www.tapplastics.com).
>
> Regards,
> Ray
>
> Brian Cox wrote:
> >
> >  Pierre,
> >
> >          I'm not sure what the chemical is for lamiating two sheets of
Plexiglass together is.  But where ever they sell acrylic they usally have
it on hand.  I know it is very volitile and you should have good venilation
when using it.  As with most such materials you don't want to breath it !  I
will try and find the name of it.
> >
> > Brian
> >
> > ----- Original Message -----
> > From: "Pierre Poulin" <pipo305@hotmail.com>
> > To: <personal_submersibles@psubs.org>
> > Sent: Monday, January 12, 2004 10:24 AM
> > Subject: RE: [PSUBS-MAILIST] Acrylic laminating
> >
> > > Hello,
> > >
> > > I can't answer your question but I would like to know what product to
use to
> > > bond acrylic?
> > >
> > > Thanks you very much!
> > >
> > > Pierre Poulin
> > >
> > >
> > > >From: "Brian Cox" <ojaibees@ojai.net>
> > > >Reply-To: personal_submersibles@psubs.org
> > > >To: <Personal_Submersibles@psubs.org>
> > > >Subject: [PSUBS-MAILIST] Acrylic laminating
> > > >Date: Mon, 12 Jan 2004 09:09:19 -0800
> > > >
> > > >Hi,   I have an idea that perhaps has not been considered before with
> > > >respect to acrylic domes / viewports.   First off let me say that
there
> > > >is a good chance that this would generally be a bad idea but since I
> > > >don't know that much about the structure of acrylic I will proceed.
> > > >
> > > >  I've noticed with acrylic sheets that they can be laminated
together
> > > >with some type of bonding agent.  I've seen this in large pieces of
> > > >acrylic art work.  They do this to add color in places and for other
> > > >effects.  I'm wondering if a dome was made using say 2" thick acrylic
> > > >sheets laminated together so that you had say 5 sheets of 2" acrylic
> > > >laminated together that would make it so you could have a 9" dome
radius
> > > >if you machined the interior.  Or if the 2" sheets were cut into
donuts
> > > >first you would have a lot less machining to do to make the final
dome.
> > > >So the finished product would be an acrylic dome 2" thick made up of
> > > >five layers of acrylic.  The question is how thorough is the bonding
> > > >between the layers of acrylic?   And if a dome was made like this and
> > > >then taken down to depth what would be the destruction
characteristics
> > > >that would occur?    I doubt that the handbook for acrylic for
> > > >submersibles addresses this idea but there may be some hint of it if
it
> > > >addresses laminating acrylic.   The chemical that is used to bond the
> > > >sheets is like an acetone type, I believe, and the sheets are
> > > >essentially bonded chemically in this way but I am not very
> > > >knowledgeable on the details.  If this was a viable method it could
> > > >reduce the cost of producing a dome.  I'm ready to be shot down!
> > > >
> > > >Brian Cox
> > >
> > > _________________________________________________________________
> > > MSN Messenger : discutez en direct avec vos amis !
> > > http://messenger.fr.msn.ca/
> > >
> > >
>