[PSUBS-MAILIST] annealing acrylic

Tue Apr 1 21:40:34 EDT 2014

Adding thermal mass inside an oven actually destabilizes closed loop 
control, as you have just learned.

With open loop control it can help a bit by ironing out fluctuations.

Best,
Marc

On 4/2/2014 2:02 AM, Alan wrote:
> Brian,
> I was going to suggest earlier that you build a larger oven next to your
> small
> oven & use the small oven to heat it. That way the temperature fluctuations
> would be less dramatic.  Possibly make it out of insulation batts &
> aluminium foil.
> you could still use the control unit I suggested.
> Alan
>
> Sent from my iPad
>
> On 2/04/2014, at 3:49 am, "Brian Cox" <brian at ojaivalleybeefarm.com
> <mailto:brian at ojaivalleybeefarm.com>> wrote:
>
>> Epic Fail !    my attempt to anneal a viewport did not go well.   The
>> temps swings were so great that it was impossible to regulate.  The
>> mass in the oven that I had hoped would moderate the swings made it so
>> the lag time between the heating cycle and when the thermometer sensor
>> saw the temperature change uncontrollable.   And the heat was not even
>> though out the oven as well.
>> Brian
>>
>> --- hanker_20032000 at yahoo.ca <mailto:hanker_20032000 at yahoo.ca> wrote:
>>
>> From: hank pronk <hanker_20032000 at yahoo.ca
>> <mailto:hanker_20032000 at yahoo.ca>>
>> To: Personal Submersibles General Discussion
>> <personal_submersibles at psubs.org <mailto:personal_submersibles at psubs.org>>
>> Subject: Re: [PSUBS-MAILIST] annealing acrylic
>> Date: Tue, 25 Mar 2014 05:35:51 -0700 (PDT)
>>
>> Brian,
>> I say when in doubt, test.  If your not building a test chamber , you
>> can make your sample window to fit my chamber and I will test it for you.
>> Hank
>>
>>
>> On Monday, March 24, 2014 7:23:18 PM, Brian Cox
>> <brian at ojaivalleybeefarm.com <mailto:brian at ojaivalleybeefarm.com>> wrote:
>> Hank,
>>           I have the book, that's where the annealing schedules are,
>> they vary quite a bit, there is an absolute minimum time and then
>> there is the original recommended time. The recommended time comes out
>> to be around 51 hours where as the shortened time is maybe half that.
>> I'm just doing one test piece to start off with.  I was also using the
>> same oven ( a toaster oven I got from Sears for $75 bucks) to heat the
>> welding rod to 250 degrees F before we used the rod ( it had been
>> sitting out for a few days).  I was able to keep the temperature
>> fairly even for the welding rod at 250.
>> Brian
>>
>> --- hanker_20032000 at yahoo.ca <mailto:hanker_20032000 at yahoo.ca> wrote:
>>
>> From: hank pronk <hanker_20032000 at yahoo.ca
>> <mailto:hanker_20032000 at yahoo.ca>>
>> To: Personal Submersibles General Discussion
>> <personal_submersibles at psubs.org <mailto:personal_submersibles at psubs.org>>
>> Subject: Re: [PSUBS-MAILIST] annealing acrylic
>> Date: Mon, 24 Mar 2014 17:39:27 -0700 (PDT)
>>
>> Brian,
>> Do you have the Stachiw book of Acrylics, I can send you mine if you
>> don't have a copy.  There is some pretty important stuff in there.
>> Hank
>>
>>
>> On , hank pronk <hanker_20032000 at yahoo.ca
>> <mailto:hanker_20032000 at yahoo.ca>> wrote:
>> Brian,
>> How thick is your acrylic?  should take more than a night?
>> Hank
>>
>>
>> On Monday, March 24, 2014 6:33:09 PM, Brian Cox
>> <brian at ojaivalleybeefarm.com <mailto:brian at ojaivalleybeefarm.com>> wrote:
>> Yes, I have the annealing schedules.  I have an electric oven and two
>> digital thermometers, one I'm going to put in a piece of acrylic and
>> the other one I'm going to use to monitor the oven temperature itself
>> .  I'm worried that the thermometer in the acrylic won't register
>> until it gets heated throughout, and so then the oven temp might go
>> higher than it should.  So between the two readouts I can heat it
>> gradually up.  It'll be a long night.
>> Brian
>>
>> --- hanker_20032000 at yahoo.ca <mailto:hanker_20032000 at yahoo.ca> wrote:
>>
>> From: hank pronk <hanker_20032000 at yahoo.ca
>> <mailto:hanker_20032000 at yahoo.ca>>
>> To: Personal Submersibles General Discussion
>> <personal_submersibles at psubs.org <mailto:personal_submersibles at psubs.org>>
>> Subject: Re: [PSUBS-MAILIST] annealing acrylic
>> Date: Mon, 24 Mar 2014 17:22:32 -0700 (PDT)
>>
>> Brian,
>> Are you going to anneal your windows yourself?
>> Hank
>>
>>
>> On Monday, March 24, 2014 6:03:10 PM, Brian Cox
>> <brian at ojaivalleybeefarm.com <mailto:brian at ojaivalleybeefarm.com>> wrote:
>> Used my polarized lenses on the newly cut piece and it appears clouded
>> throughout the whole piece.  Where as another piece I have, you can
>> clearly see a stress area around where it has been drilled.
>> Brian
>>
>> --- emile at airesearch.nl <mailto:emile at airesearch.nl> wrote:
>>
>> From: "Emile van Essen" <emile at airesearch.nl <mailto:emile at airesearch.nl>>
>> To: "'Personal Submersibles General Discussion'"
>> <personal_submersibles at psubs.org <mailto:personal_submersibles at psubs.org>>
>> Subject: Re: [PSUBS-MAILIST] annealing acrylic
>> Date: Mon, 24 Mar 2014 22:40:46 +0100
>>
>> As far as I know it is only cast.
>> Regards, Emile
>> *Van:*Personal_Submersibles
>> [mailto:personal_submersibles-bounces at psubs.org] *Namens *Brian Cox
>> *Verzonden:* maandag 24 maart 2014 20:37
>> *Aan:* PSubs
>> *Onderwerp:* [PSUBS-MAILIST] annealing acrylic
>> I'm planning on annealing my viewports,  does anyone know if the
>> acrylic from the factory is pre-shrunk ?
>> 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 <mailto: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
>>
>> _______________________________________________
>> Personal_Submersibles mailing list
>> Personal_Submersibles at psubs.org <mailto: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
>>
>> _______________________________________________
>> Personal_Submersibles mailing list
>> Personal_Submersibles at psubs.org <mailto:Personal_Submersibles at psubs.org>
>> http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles
>>
>>
>> _______________________________________________ Personal_Submersibles
>> mailing list Personal_Submersibles at psubs.org
>> </eonapps/ft/wm/page/compose?send_to=Personal_Submersibles%40psubs.org> http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles
>
>> _______________________________________________
>> Personal_Submersibles mailing list
>> Personal_Submersibles at psubs.org <mailto: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
>

-- 
Archivale catalog: http://www.archivale.com/catalog
Polymath weblog: http://www.archivale.com/weblog
Translations (ProZ profile): http://www.proz.com/profile/639380
Translations (BeWords profile): http://www.bewords.com/Marc-dePiolenc
Ducted fans: http://massflow.archivale.com/