[PSUBS-MAILIST] annealling

[hank pronk via Personal_Submersibles]

Brian,
Is the port irregular in thickness after annealing.
Hank--------------------------------------------
On Thu, 10/16/14, Brian Cox via Personal_Submersibles <personal_submersibles at psubs.org> wrote:

 Subject: Re: [PSUBS-MAILIST] annealling
 To: "Personal Submersibles General Discussion" <personal_submersibles at psubs.org>
 Received: Thursday, October 16, 2014, 7:26 PM
 
 Hi
 Sean,                  The disk
 diameters shrink by .120 "  ( for a 6" dia disk)
 - 2%  and the thickness increases slightly, that is in
 agreement with info from Stachiw ( Handbook of Acrylics) 
 .  But I noticed some slight variation of the
 material before the annealing process.  There is no
 distortion or anything like that .  I guess the slight
 variation of 20 thousandths will be inconsequential once the
 gaskets and squeezed on with the retaining
 ring. Brian   
 
 --- personal_submersibles at psubs.org wrote:
 
 From: "Sean T. Stevenson
 via Personal_Submersibles"
 <personal_submersibles at psubs.org>
 To:
 Personal Submersibles General Discussion
 <personal_submersibles at psubs.org>
 Subject: Re: [PSUBS-MAILIST] annealling
 Date: Thu, 16 Oct 2014 16:02:07 -0600
 
 Brian, cast
 acrylic will exhibit some natural shrinkage as you approach
 thermoforming temperatures - it could be that you are seeing
 the beginning of this at your annealing temperature. Is the
 discrepancy in thickness only, or are your diameters off as
 well?
 Barring any obvious visual abberation, I'd
 be inclined to use the windows as per the minimum measured
 thickness. If there is visual distortion, you might want to
 flatten it and then run it through annealing again. Once the
 shrinkage has occurred, you shouldn't see it again.
 Sean
 
 
 
 
 On October 16, 2014 2:45:18
 PM MDT, Brian Cox via Personal_Submersibles
 <personal_submersibles at psubs.org> wrote:
 Hi
 All,            Been annealing my
 disks, I've been just standing them on end in the
 oven.  I'm seeing a tiny variation of the thickness of
 the acrylic, at first I thought it was because of standing
 them on end ,  but I think there is actually some variation
 in the thickness of the original material.  The most
 I've seen is .020   .  I guess it's nothing to be
 concerned about.  Anyone have any info on
 this? Brian
 
 Personal_Submersibles mailing list
 Personal_Submersibles at psubs.org
 http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles
 _______________________________________________
 Personal_Submersibles mailing list
 Personal_Submersibles at psubs.org
 http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles
 
 -----Inline Attachment Follows-----
 
 _______________________________________________
 Personal_Submersibles mailing list
 Personal_Submersibles at psubs.org
 http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles