Pyrex Cup Shattered

[Ts656577]

Hey everyone.  I was attempting to pour some baits last night.  This is my first time using this cup.  I was using an IMUSA hot plate on the low setting (the dial lined up with the "L" of Low).  I poured one, put it back on to stay warm while i demolded.  Attempted to pour another and it shattered in my hand. Luckily I didn't get plastic on myself.  I only ruined a rug.  

 

Can anyone tell me why this might have happened?  I dont think I heated up the plastic too quickly.  It took a good 10 min or so.  

 

Edited June 29, 2016 by Ts656577

[mark poulson]

Pyrex, and all tempered glass products, are under tension.  They are tempered by cooling the outside quickly.  It's almost like case hardening.

The heating/cooling cycle causes fatigue.  

They can fatigue, and break.  

Your cup may have been manufactured with a slight defect that made it fail more easily.

Thinner containers seem to last longer, because there is less glass to be affected by the heat/cool cycle, so they expand and contract more evenly.

Somewhere on TU is a thread about thinner beakers that seem to hold up better.

[Cami]

If I am not wrong the IMUSA hot plate is an electric burner plate.

Directly copied by Pirex site about Pyrex® 2 Cup Measuring Cup

:

Q: 

Can this be used directly on a stove top, such as an electric burner?

Asked on 10/8/2014 by Marina from Mass

Know the answer? Answer this question

1 answer

• 

   

  A:

   No, as with all Pyrex glassware, this measuring cup is not safe for use on a stovetop.

   

  Answered on 10/22/2014 by Brett from WKConsumerCare

Bye

 

Cami

[mark poulson]

I have seen Frank's setup, and he uses a hot plate, but it is some kind of a warming tray, not an exposed element.

 

http://www.tackleunderground.com/community/topic/20895-two-color-ripper-baits-and-production-video/

Edited June 29, 2016 by mark poulson

[archery1]

put a fry pan,, cast iron pan.. etc.. then ur pyrex cup.. i saw someone have a huge fry pan and they set their pyrex on it.. then put sand mixed with some kind of adhesive (so it didnt move ) and set their cups in spots and he said that it kept plastic heated better. I personally use a cheap  pan i got at public sale big enough for 2  cup pyrex to fit on ,Has never been a problem and makes shooting laminates easy once you find the correct setting on hot plate. Keeps both the plastics the same temp.

[ipt]

the plate itself is probably what did it. a griddle is a better option, but still not advised.

[Frank]

I have been using a high sided griddle for years now and even if some say it's not advised it works. Two statements said would lead me to believe it was one or two things that could have happened. One is don't put it directly on a hot plate, the temp on those things jump around way to much. Temps will fluxuate from way to low to way to high but the average may be the low setting. The other is because it is new it may have a defect. Most of the ones you see here were new or near new and broke(exploded if you like drama). I did find some of the borosilicate ones and they seem to work fine but then my others have never broke after 7 years of use. The new ones I have found were thicker just like the Pyrex cups most use. Try a high sided griddle or pan and you will see a difference and if it does break it will be in the pan and not the carpet.

On a side note i have had the new ones for awhile now and the only difference I see in them is they don't clean out as easy as the Pyrex.