Breaking Glass...

xelexo
Shop deals on ebay
Advertise with us
shop deals on amazon
Gold Refining Forum

Help Support Gold Refining Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.
K

kroutonz

Active member
Joined
Nov 21, 2010
Messages
36
I have broken the plate underneath my glass 3 times now trying to heat AR. I had aluminum sheet underneath a stoneware dish which held my beaker and I still broke the plate. I also heated this very slowly, just barely boiling after an hour..

I'm at a loss for what to get next in terms of vessel to hold a beaker. Will graniteware work, I know probably not the best since its a base metal with coating on it, but these glass/pyrex/stoneware isn't working. I haven't seen exactly "corningware" but I assume the stoneware is the same material or close.

http://www.amazon.com/Proctor-Silex-34101-Proctor-Silex-Burner/dp/B000690WNU/ref=sr_1_3?s=kitchen&ie=UTF8&qid=1297212507&sr=1-3 Is the hotplate I use,

Is the problem maybe with the temperature outside (30f), and me heating to about 200(f) or so may leave the outter edges of the glass cold enough to break it? Or is it possibly the burner just being too hot (1000w) and I should get a more precise one with temp guage? Open to suggestions, I thought about sand but it doesn't really seem ideal, and I feel like its just going to take longer to heat up and have the same thing happen.
 
kroutonz said:
I have broken the plate underneath my glass 3 times now trying to heat AR. I had aluminum sheet underneath a stoneware dish which held my beaker and I still broke the plate. I also heated this very slowly, just barely boiling after an hour..

I'm at a loss for what to get next in terms of vessel to hold a beaker. Will graniteware work, I know probably not the best since its a base metal with coating on it, but these glass/pyrex/stoneware isn't working. I haven't seen exactly "corningware" but I assume the stoneware is the same material or close.

http://www.amazon.com/Proctor-Silex-34101-Proctor-Silex-Burner/dp/B000690WNU/ref=sr_1_3?s=kitchen&ie=UTF8&qid=1297212507&sr=1-3 Is the hotplate I use,

Is the problem maybe with the temperature outside (30f), and me heating to about 200(f) or so may leave the outter edges of the glass cold enough to break it? Or is it possibly the burner just being too hot (1000w) and I should get a more precise one with temp guage? Open to suggestions, I thought about sand but it doesn't really seem ideal, and I feel like its just going to take longer to heat up and have the same thing happen.
Click to expand...

I've heard that a very specific type of corningware dish holds up well against the heat. Also the type of hotplate your using is not really designed for lab use.

GSP recommended this one:
http://www.shopworldkitchen.com/corningware/stovetop-just-white-casserole-jw-5c-b
 
http://goldrefiningforum.com/phpBB3/viewtopic.php?f=39&t=8758&hilit=+corningware#p82327
 
kroutonz said:
I have broken the plate underneath my glass 3 times now trying to heat AR. I had aluminum sheet underneath a stoneware dish which held my beaker and I still broke the plate. I also heated this very slowly, just barely boiling after an hour..

I'm at a loss for what to get next in terms of vessel to hold a beaker. Will graniteware work, I know probably not the best since its a base metal with coating on it, but these glass/pyrex/stoneware isn't working. I haven't seen exactly "corningware" but I assume the stoneware is the same material or close.

http://www.amazon.com/Proctor-Silex-34101-Proctor-Silex-Burner/dp/B000690WNU/ref=sr_1_3?s=kitchen&ie=UTF8&qid=1297212507&sr=1-3 Is the hotplate I use,

Is the problem maybe with the temperature outside (30f), and me heating to about 200(f) or so may leave the outter edges of the glass cold enough to break it? Or is it possibly the burner just being too hot (1000w) and I should get a more precise one with temp guage? Open to suggestions, I thought about sand but it doesn't really seem ideal, and I feel like its just going to take longer to heat up and have the same thing happen.
Click to expand...

if the temp is not adjustable or if it goes full throttle till it reaches temp could be a issue....

if a 1Kw element is on full blast to temp that is 2000 BTU's ..that is alot of concentrated heat... it all varies though....

i use this one http://www.walmart.com/ip/Rival-11-Electric-Skillet/10598475#ProductDetail

this is not lab quality but with the pan it will catch majority of material dumped incase of break......

how do you store your materials to make AR..... you keep them outside??? if so i would recommend allowing to reach room temp before application of heat...

hope this helps
 
Try using a sheet of 1/8+ steel under your pans and raise your heat slowly leaving the pans on there until cool, I used this method for years with the beakers directly on the steel and had very few break,thankfully!
 
Krountonz mentions using a sheet of aluminum, but it must be awfully thin and Al is a very good conductor of heat. If Al is used I think it should be 1/4 inch or more thick. Al doesn't store or slow down heat flow near as well as steel/iron and cast iron skillets or griddles are very cheap. Having the pan or griddle overly large should help warm the air around your glass as well and reduce thermal shocks.

I"m inclined to agree with Godofwar about your hot plate controller might be a big part of the problem. My litte hot plate is 750 watts and I barely crank it open when I'm heating a small beaker set in a little Corningware fry pan rated for direct stove top.

FrugalEE
 
IMHO, these make all the difference - gas or electric burners
http://goldrefiningforum.com/phpBB3/download/file.php?id=4900
 
For heat transfer, I use Silicone fluid that was designed for the purpose when heating beyond the boiling point of Water. I keep the flask suspended in the fluid so that the heat is applied over the whole bottom of the flask. This limits the formation of hot spots in the glass that might stress the vessel.
Another thing to watch for are scratches on the surface of the glass. These can cause it to fail much sooner than a pristine surface.
 
Irons said:
For heat transfer, I use Silicone fluid that was designed for the purpose when heating beyond the boiling point of Water. I keep the flask suspended in the fluid so that the heat is applied over the whole bottom of the flask. This limits the formation of hot spots in the glass that might stress the vessel.
Another thing to watch for are scratches on the surface of the glass. These can cause it to fail much sooner than a pristine surface.
Click to expand...

does this fluid you speak of also work with cooling?
 
lasereyes said:
Irons said:
For heat transfer, I use Silicone fluid that was designed for the purpose when heating beyond the boiling point of Water. I keep the flask suspended in the fluid so that the heat is applied over the whole bottom of the flask. This limits the formation of hot spots in the glass that might stress the vessel.
Another thing to watch for are scratches on the surface of the glass. These can cause it to fail much sooner than a pristine surface.
Click to expand...

does this fluid you speak of also work with cooling?
Click to expand...

I don't see why not. It's designed to remain free-flowing at very low temperatures, so, yes, you could use it for temperatures below freezing, but a cheaper solution would be to use anti-freeze in your cooling water. Anti-freeze is what I use to keep my glassware from breaking from the cold.
You can also add Calcium Chloride to water so that it boils above 100 deg.C if you need a cheap fix and you don't need to get too hot. Silicone fluid is nice because you don't have to babysit it and it cleans up from the glassware easily; just a wipe with a paper towel.
 
Yes my aluminum sheet was about 1/8inch maybe less.. but I've decided i'm just going to get a cheap scientific hotplate/stirrer combo on ebay. I'm gonna try and finish this batch of ar without a cw dish which i figure the 180w heating power should be fine to not break a pyrex beaker.

Also I read up that the hotplate i have does go full blast/off cycles until it reachs the right temperature so that could of been the problem.
 
Instead of using an aluminum plate we us ceramic fiber paper

http://www.cooltools.us/Ceramic-Fiber-Paper-p/kln-805.htm

it seems to balance the heat better
 
https://www.pelletlab.com/magnetic_stirrer

link to the one I'm probably going to get. Thinking about the ceramic since I dont think I would need to use a stir bar in hot liquid often.
 
kroutonz said:
https://www.pelletlab.com/magnetic_stirrer

link to the one I'm probably going to get. Thinking about the ceramic since I dont think I would need to use a stir bar in hot liquid often.
Click to expand...

Being able to use a stir bar comes in real handy. I would get it if I were you.
 
You know I’ve been thinking about this for awhile now and trying to come up with a simple effective method. I just wonder..........

Lets look at inductive heating for a moment. With induction heating all your heating is a metal substance. What if you took a glass beaker and placed it on an induction cook top and heated it? The glass would not be affected by thermal shock. All that would heat is the surface of any metals in the solution. The metals would heat up on the surface reacting with the solution instead of you having to heat the whole solution up to react with the metals.

Hummmm...... http://www.walmart.com/ip/GE-Electric-Induction-Cooker/8224072
 
In theory you are correct. But in practical experience I can tell you from my point of view being able to stir the solution and heat makes things go a lot faster IMHO. Take for instance now, my heater is out on my hot plate so I have to put my container on a hot plate and then put it on the stirrer to make things go faster.
 
Think i might go to wally world later and get on of these to take apart and see if i can play with it. Hummmm......
 
Easiest is to put beaker/champagne bottle/reaction tank/whatever on a thermos jacket (fiberglass-resin exterior. insulation wool middle, champagne bottle inside), and preheat the acids, then the chemical reaction keeps everything warm. If you want good stirring just plug it and shake it if small or put it on a trolley and rock it backwards and forwards if big.:shock:
 
for a stirrer i bought a candy thermometer glass with a steel support.... then i removed the steel section...... so i have temp reference and stirrer in one...
 

Latest posts

Back
Top