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Topic: Wasted a good flask....  (Read 10252 times)

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Offline khemikuhlz

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Wasted a good flask....
« on: April 13, 2010, 08:04:29 AM »
So the other day I finally obtained my first pieces of glassware.
I got these from an antique store relatively cheap.
-50ml beaker
-150ml grad. cylinder
-stirring rod
-250ml flask
All pyrex...

Anywho...
I broke the flask while heating a solution of copper chloride to cook off the water.
It just straight up shattered!

Is this because the glassware was simply too old?

I am using a propane torch type thing btw. I got a hold of a small propane burner with a nice little valve and such that seems to fill in nicely for a Bunsen burner...

Like a BOSS.

Offline 408

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Re: Wasted a good flask....
« Reply #1 on: April 13, 2010, 11:38:06 AM »
Torches are fine for heating solutions but hydrated powders in glass flasks are a no-no.

When dry the glass and the newly-formed solid may have different expansion rates and if they stick to one another the glass can crack.

Right at the point the solid looses all liquid, the water can condense in the upper regions of the flask, dropping onto the now-overheated glass.  This can crack glass too.

I have had both happen.

Offline khemikuhlz

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Re: Wasted a good flask....
« Reply #2 on: April 13, 2010, 12:06:53 PM »
Dude. It broke my heart. I'm tellin' ya.
 :-[
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Offline skyjumper

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Re: Wasted a good flask....
« Reply #3 on: April 13, 2010, 07:28:37 PM »
Flasks aren't that expensive, Check out UnitedNuclear or ebay (FYI, good idea to get a porcelain crucible or evaporating dish too)

Offline nj_bartel

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Re: Wasted a good flask....
« Reply #4 on: April 13, 2010, 07:36:16 PM »
UN's flasks aren't ground glass jointed, fyi

Offline khemikuhlz

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Re: Wasted a good flask....
« Reply #5 on: April 13, 2010, 08:18:06 PM »
Thanks everyone. All very useful information.

My problem is that it's just kinda hard to find lab ware without buying online (which I shy away from).
I guess I'll have to just suck it up and do it though...

I know United Nuclear is popular, but what about the www.sciplus.com link on the society for amateur scientists website, www.sas.com, listed in the Common Sources of Chemicals Listed by The Society for Amateur Scientists thread?
Are they any good? If anyone has any experience with them, shared knowledge is appreciated.
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Offline hobobot

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Re: Wasted a good flask....
« Reply #6 on: April 14, 2010, 11:47:54 AM »
those flasks on sciplus are a great price, especially for a 2000ml. I usually get my stuff on ebay, but that website looks good too.

Offline Rogeryermaw

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Re: Wasted a good flask....
« Reply #7 on: September 20, 2010, 12:39:14 AM »
my best technique for drying solid chemicals is in a 9" pyrex pie pan in the oven. for toxic chems consider getting a toaster oven at walmart that will be dedicated for this purpose. they aren't too expensive and have some pretty good convection type models but definitely don't heat your lab glassware with only dry chems in it and it is also advisable not to use open flame to heat glass directly.

Offline Grundalizer

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Re: Wasted a good flask....
« Reply #8 on: October 23, 2010, 09:15:59 PM »
If you do use an open flame, use a crucible or ceramic material.  If you must use glassware, keep the flame continually moving around the glassware, take it off for 2 or 3 seconds, then heat again for a few seconds.  You should never just keep a full blown butane torch on a piece of glassware.

Also, don't be afraid to order a couple pieces of glassware online...people do it ALL the time.  I think the paranoia level is a little too high surrounding DIY chemistry and science.

Sure, if you order pounds of nitrates and 5L round bottom flasks maybe someone might look into it, but small amounts here and there of random lab equipment is nothing.  Should never let your government scare you about experimenting, as long as you are thinking about the safety of yourself and others, and dispose of waste properly, because in the end, that waste will end up back in your water supply, or your kids water supply.

Offline Glassblower

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Re: Wasted a good flask....
« Reply #9 on: January 24, 2011, 10:57:17 AM »
You're right about the direct flame on the glass.The better wat to go is a hot plate or heating mantle.
I have some used flasks for sale,if you need some.

Offline Eddie Zheng

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Re: Wasted a good flask....
« Reply #10 on: May 03, 2011, 08:40:21 PM »
Hey, Its OK, I have broken 3 pieces of 50 year old pieces of glassware. You'll get over it...
 ;)
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Offline zaphraud

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Re: Wasted a good flask....
« Reply #11 on: June 08, 2011, 10:57:50 AM »
Right at the point the solid looses all liquid, the water can condense in the upper regions of the flask, dropping onto the now-overheated glass.  This can crack glass too.
Sounds like a good reason to use the microwave to me...

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