Re: [PSUBS-MAILIST] Acrylic laminating

["Brian Cox" <ojaibees@ojai.net>]

How would you "stress-relieve" it after machining?  I not sure what process you are referring to?  

Brian Cox
----- Original Message ----- 
From: "Dan H." <jmachine@adelphia.net>
To: <personal_submersibles@psubs.org>
Sent: Thursday, January 15, 2004 8:20 PM
Subject: Re: [PSUBS-MAILIST] Acrylic laminating


> 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/
> > > >
> > > >
> >
> 
> 
>