<DIV style="font-family:Arial, sans-serif; font-size:10pt;"><DIV>Alec, That's what I was thinking, but the oven has a very even temperature. Earlier, when I was experimenting I had 6 or 7 digital temp gages placed at various places in the oven and the temp did not vary all that much, maybe 15 degrees from the top to the bottom. It's just a standard oven I got from a junk yard, but I pulled everything out of it and am running small electric coil with a vary-ac . I'm thinking that once the acrylic goes through multiple cycles it starts to degrade from the high heat.</DIV><DIV> </DIV><DIV>Brian C<BR><BR>--- personal_submersibles@psubs.org wrote:<BR><BR>From: Alec Smyth via Personal_Submersibles <personal_submersibles@psubs.org><BR>To: Personal Submersibles General Discussion <personal_submersibles@psubs.org><BR>Subject: Re: [PSUBS-MAILIST] annealing windows<BR>Date: Sun, 22 Nov 2015 06:23:39 -0500<BR><BR></DIV><DIV dir="ltr">Phew! I'll ask Greg Cottrell that question, I can't think why the placebo window would melt and not the others. Years ago I recall him saying he had had to experiment quite a lot with fans inside the oven until he got temperatures even. Maybe its just one part of the oven getting hotter than the rest of it.<DIV><BR></DIV><DIV>Best,<BR><BR>Alec</DIV></DIV><DIV><BR><DIV>On Sat, Nov 21, 2015 at 11:27 PM, Brian Cox via Personal_Submersibles <SPAN dir="ltr"><<A href="mailto:personal_submersibles@psubs.org">personal_submersibles@psubs.org</A>></SPAN> wrote:<BR><BLOCKQUOTE style="margin: 0px 0px 0px 0.8ex; padding-left: 1ex; border-left-color: rgb(204, 204, 204); border-left-width: 1px; border-left-style: solid;"><DIV style="font-family: Arial,sans-serif; font-size: 10pt;"><DIV>Alec, yes, correct, the window with the hole for the probe is just to monitor the temp. I wonder if any of those psubers across the pond would have any experience with something like this.</DIV><DIV> </DIV><DIV>Brian C.<BR><BR>--- <A href="mailto:personal_submersibles@psubs.org">personal_submersibles@psubs.org</A> wrote:<BR><BR>From: Alec Smyth via Personal_Submersibles <<A href="mailto:personal_submersibles@psubs.org">personal_submersibles@psubs.org</A>><BR>To: Personal Submersibles General Discussion <<A href="mailto:personal_submersibles@psubs.org">personal_submersibles@psubs.org</A>><BR>Subject: Re: [PSUBS-MAILIST] annealing windows<BR>Date: Sat, 21 Nov 2015 23:00:28 -0500<BR><BR></DIV><DIV><DIV><DIV dir="ltr">Brian, just to make sure I understand... I presume the window with the hole was a "placebo" you threw in the oven along with the actual windows, to monitor temperature rise? Else, if you drilled a partial hole into one of the actual windows unfortunately my reaction would be a very big UH-OH!!! That would be a stress concentrator in a spot where you <U>really</U> do not want one.<DIV><BR></DIV><DIV><BR></DIV><DIV>Best,</DIV><DIV><BR>Alec<BR><DIV><BR></DIV><DIV> </DIV></DIV></DIV><DIV><BR><DIV>On Sat, Nov 21, 2015 at 10:32 PM, Brian Cox via Personal_Submersibles <SPAN dir="ltr"><<A href="mailto:personal_submersibles@psubs.org">personal_submersibles@psubs.org</A>></SPAN> wrote:<BR><BLOCKQUOTE style="margin: 0px 0px 0px 0.8ex; padding-left: 1ex; border-left-color: rgb(204, 204, 204); border-left-width: 1px; border-left-style: solid;"><DIV style="font-family: Arial,sans-serif; font-size: 10pt;"><DIV>Had a weird observation while annealing my windows, I have one window that I drilled a 1/8' deep hole for a temperature probe so I can monitor the rise of the acrylic. After the annealing, the one window with the probe, it's surface was badly melted. The rest of the windows were perfectly fine. The only difference was that the window with the probe has gone through multiple annealing cycles. It was also sitting on another piece of thick acrylic, but I don't think that would have anything to do with it's surface being melted.</DIV><SPAN><FONT color="#888888"><DIV> </DIV><DIV>Brian Cox</DIV></FONT></SPAN></DIV>
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