andre178
Hazard to Self
Posts: 61
Registered: 11-12-2009
Location: San Diego, CA
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Mood: pacified
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temp of 450 deg C in a lab
Hi there, I'm curious how I would be able to find a clever way to heat a round bottom flask to 450 deg C without using a heating mantle or oven. Or
would I have to go that route?
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peach
Bon Vivant
Posts: 1428
Registered: 14-11-2008
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A blowtorch. Carefully applied.
Some hot air guns for stripping paint can manage 600C, and even future a temperature dial. But the noise will drive you to insanity over the coarse of
hours.
Mine was about £25 or 30. Comes with all those handy dandy fittings for DIY tasks.
Hot air guns that reach those temperatures can be had for £15, or even free if you know someone who's got one and never uses it (stripping paint is
not a regular activity for many people). 450C is approaching the no go area for borosillicate glass. It's usually not used over 250C, because most of
the greases and plastics used to clip and seal it together will be falling apart by that point.
Using blow torches and hot air guns right up against the glass for prolonged periods of time, then instantly turning them off, may thermally shock the
glass; you need to take care if it's something expensive.
A regular propane blowtorch is capable of distorting and even melting glass. You need to start with it away and gradually move them together until you
get the temperature you want. If you are running an exothermic reaction, it may kick off and rocket the temperature up to the melting point by it's
self.
This is usually the point at which borosillicate gets swapped for quartz.
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Hexavalent
International Hazard
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Registered: 29-12-2011
Location: Wales, UK
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I will have to agree with peach . . .I have but one quartz tube for high temperature operations.
How bad is the noise from a heat gun then?
"Success is going from failure to failure without loss of enthusiasm." Winston Churchill
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peach
Bon Vivant
Posts: 1428
Registered: 14-11-2008
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A hot air gun is just a hair drier with a metal nozzle in place of the plastic. Sounds exactly the same as well. Fine for five minutes, not for five
hours. Can always stick some earplugs in.
The element in both will manage about a thousand degrees C. But the hot air gun as a whole is unlikely to be happy with that. I've seen what it does
to a hair drier. The conclusion is a two foot flame out the end.
[Edited on 23-3-2012 by peach]
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