Comments on: Glastherm HT Insulation with Glass Standoffs for Hotplates http://www.neufeld.newton.ks.us/electronics/?p=994 Sun, 08 Dec 2024 17:19:24 -0600 hourly 1 http://wordpress.org/?v=3.1.3 By: Bill http://www.neufeld.newton.ks.us/electronics/?p=994&cpage=1#comment-25943 Bill Tue, 03 Aug 2010 20:04:02 +0000 http://www.neufeld.newton.ks.us/electronics/?p=994#comment-25943 Mica is a far better insulator than Glastherm. Thermal conductivity is far lower than Glastherm. Seems Mica lets the heat spread side to side better also. Mica is a far better insulator than Glastherm. Thermal conductivity is far lower than Glastherm. Seems Mica lets the heat spread side to side better also.

]]> By: Jeff http://www.neufeld.newton.ks.us/electronics/?p=994&cpage=1#comment-25029 Jeff Thu, 06 May 2010 19:38:47 +0000 http://www.neufeld.newton.ks.us/electronics/?p=994#comment-25029 One hotplate design that I have studied used stainless steel standoffs and a U shaped piece of stainless sheet to support the heated stage from the sides. This seemed to work fairly well as stainless is a relatively poor conductor of heat. I doubt that the stainless was cool to the touch, but it was cool enough that the aluminum plate it was attached to (I forget if it was bolted or glued) didn't get very warm. Something to think about... One hotplate design that I have studied used stainless steel standoffs and a U shaped piece of stainless sheet to support the heated stage from the sides. This seemed to work fairly well as stainless is a relatively poor conductor of heat. I doubt that the stainless was cool to the touch, but it was cool enough that the aluminum plate it was attached to (I forget if it was bolted or glued) didn’t get very warm. Something to think about…

]]> By: Keegan http://www.neufeld.newton.ks.us/electronics/?p=994&cpage=1#comment-25006 Keegan Tue, 04 May 2010 05:33:34 +0000 http://www.neufeld.newton.ks.us/electronics/?p=994#comment-25006 I just started reading your blog, some very cool stuff you have going on here. I thought I'd throw in my own 2 cents... As far as thermal insulation goes, air is one of the best so it makes sense that your glass standoffs do a good job. Heat transfer works just like current transfer, and your glass bits work just like little resistors. More to the point, you'll double your thermal resistivity if you add another layer of glass squares. For heating in general, the commercial RP machines I've seen also control the temperature in the entire chamber (not just the base surface) to around 90 degrees or so. Maybe this is 'phase two' of this sub project, but it would seem like this would have a greater benefit. Keep up the great work I just started reading your blog, some very cool stuff you have going on here. I thought I’d throw in my own 2 cents…
As far as thermal insulation goes, air is one of the best so it makes sense that your glass standoffs do a good job. Heat transfer works just like current transfer, and your glass bits work just like little resistors. More to the point, you’ll double your thermal resistivity if you add another layer of glass squares.

For heating in general, the commercial RP machines I’ve seen also control the temperature in the entire chamber (not just the base surface) to around 90 degrees or so. Maybe this is ‘phase two’ of this sub project, but it would seem like this would have a greater benefit.

Keep up the great work

]]> By: MikeS http://www.neufeld.newton.ks.us/electronics/?p=994&cpage=1#comment-25004 MikeS Tue, 04 May 2010 01:14:30 +0000 http://www.neufeld.newton.ks.us/electronics/?p=994#comment-25004 I'd suggest you double up that sandwich and make a second air gap. Be very certain the new "glass dots" do not line up with the glass dots you already have in there or you will have a direct thermal conduction path. You want the heat to have to go sideways to get from one layer of glass dots to the other. I’d suggest you double up that sandwich and make a second air gap.
Be very certain the new “glass dots” do not line up with the glass dots you already have in there or you will have a direct thermal conduction path. You want the heat to have to go sideways to get from one layer of glass dots to the other.

]]> By: John Laur http://www.neufeld.newton.ks.us/electronics/?p=994&cpage=1#comment-25002 John Laur Mon, 03 May 2010 23:22:10 +0000 http://www.neufeld.newton.ks.us/electronics/?p=994#comment-25002 Now that you have an air gap, why not blow some forced air through there? Cut some fins into the top of the glastherm layer for good measure. It would make the hotpate less efficient I guess, not that thats a huge concern if it still makes it up to temp... Now that you have an air gap, why not blow some forced air through there? Cut some fins into the top of the glastherm layer for good measure. It would make the hotpate less efficient I guess, not that thats a huge concern if it still makes it up to temp…

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