Sciencemadness Discussion Board - Bad days in the lab or with glassware?

Bad days in the lab or with glassware?

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XeonTheMGPony - 27-5-2018 at 20:21

Destroying your electric coffee grinder trying to grind steelwool into a powder for nitroarene reduction... only to find that iron powder and magnetic stirring don't work together anyway.

Ah, your pain will be very helpful to me indeed. I still may try this as an experiment, but mostly without the expectation of success!

Thank you!

don't forget very fine iron dust is super flammable! and can auto ignite if fine enough!

Hegi - 28-5-2018 at 01:45

Quote: Originally posted by nitro-genes

Destroying your electric coffee grinder trying to grind steelwool into a powder for nitroarene reduction... only to find that iron powder and magnetic stirring don't work together anyway.

I really love this post and can relate to such a thing happening to me... It is funny to see that scientists can figure out solutions for complex problems but fail at those simple ones...

Morgan - 28-5-2018 at 06:51

Quote: Originally posted by Hegi

Quote: Originally posted by nitro-genes

Destroying your electric coffee grinder trying to grind steelwool into a powder for nitroarene reduction... only to find that iron powder and magnetic stirring don't work together anyway.

I really love this post and can relate to such a thing happening to me... It is funny to see that scientists can figure out solutions for complex problems but fail at those simple ones...

That reminded me of this NASA mistake.
"In June 1988, the Discovery Space Shuttle mission was delayed because of a malfunctioning hydrogen fuel bleed valve system. The problem was traced to the linear variable differential transformer (LVDT) which produced erroneous readings for the valve position. Near liquid hydrogen temperatures, Inconel 718 used in the armature of the LVDT became strongly magnetic."
https://link.springer.com/chapter/10.1007%2F978-1-4613-9880-...

nitro-genes - 30-5-2018 at 15:46

It is always one of these unforeseen interactions in seemingly simple systems that can make large differences indeed or even lead to accidents. I mean...who could have actually predicted "a priori" that the iron powder would all cling like a single ball to the stirrer bar?

Quote: Originally posted by zed

Ah, your pain will be very helpful to me indeed. I still may try this as an experiment, but mostly without the expectation of success!

Thank you!

If you are planning to use it for reductions... a much easier method is to compact small strands of steelwool into round balls. These hardly interfere with magnetic stirring at all and are much more dense than the loose steelwool itself, while retaining surface area.

Okaris - 2-6-2018 at 00:27

I've had the ceramic mortar break into two while I was grinding my samples. Fortunately, it was nothing that super glue couldn't fix.

The Volatile Chemist - 2-6-2018 at 17:57

Quote: Originally posted by Hegi

Quote: Originally posted by nitro-genes

Destroying your electric coffee grinder trying to grind steelwool into a powder for nitroarene reduction... only to find that iron powder and magnetic stirring don't work together anyway.

I really love this post and can relate to such a thing happening to me... It is funny to see that scientists can figure out solutions for complex problems but fail at those simple ones...

At work I've been having plumbing trouble with a reactor design. Every time I come up with a good plan, halfway through the reviews someone points out something obvious I've missed, like the fact that you can't pull a vacuum through a flow-meter...

I went into my (own) lab today to do a little cleaning, since I haven't been able to do home-chem in a while, and I found that I had ruined about 6 wells in my plastic well plate by letting some solutions of butanol and butyl acetate sit in them unfortunately. They turned crusty white and the plastic became deformed and thinned in those wells.

LearnedAmateur - 12-6-2018 at 10:23

Who needs to use their brains and undo the right clamp anyway?

CE4634AC-08E0-4CF5-BE92-B040CFAA9666.jpeg - 816kB

weilawei - 16-6-2018 at 17:43

Broke a 50mL beaker just now by dropping my phone onto it. Thankfully, it was not in use.

Ahhh.. time to order a new one.

Magpie - 16-6-2018 at 18:33

Seeing a wisp of smoke rising from your stepper motor driver constitutes a bad day. Fortunately I have a spare.

weilawei - 17-6-2018 at 07:49

I have 5 drives from work, pulled because they claimed they didn't work. I haven't got around to testing them or figuring out what they need for repairs, but if anyone wanted them for parts, I'd be happy to work something out. Otherwise, I'll keep them around till my buddy and I evaluate and maybe repair them for eBay.

[Edited on 17-6-2018 by weilawei]

JJay - 2-7-2018 at 21:54

wg48 - 2-7-2018 at 23:48

Quote: Originally posted by Magpie

Seeing a wisp of smoke rising from your stepper motor driver constitutes a bad day. Fortunately I have a spare.

Perhaps you should try a hand cranked one

XeonTheMGPony - 3-7-2018 at 04:35

Was freeze drying some copper nitrate, well the crystallizing dish objected to the prerequisite freezing and turned its self into a great many pieces

Thank fully I ordered a second one from Deschem, so now it will just be the new one Vs the second, I think I'll order several more.

and not so much glasses fualt ran a hydrazine sulfate synth that from all appearances failed.

arkoma - 4-7-2018 at 11:33

Just broke my Claisen adapter. GRRRRRRR.

Ooops !

Sulaiman - 4-7-2018 at 14:09

Maybe I should change my "I don't need to wear my gloves" attitude ?

Aqua Regia vs. middle finger .....

Not painful ... just embarrassing

XeonTheMGPony - 4-7-2018 at 17:18

that looks very painfull! I wash my hands between every operation regardless if I feel any thing just for that reason!

Doped-Al2O3-fusion - 6-7-2018 at 13:31

I recently had a sad accident. The solution I was filtering was ferrous sulfate and I failed to secure my vacuum pump as I normally do. I accidentally got caught on the power cord and then sadness occurred.

I got online later and ordered two more of the same size, plus an additional coarse glass Buchner funnel. I may receive them next week or in a month or so since I order from the Chinese manufacturer directly.

happyfooddance - 7-7-2018 at 12:19

Sad day... :'(

Cracked the top of my hotplate.

Plunkett - 14-7-2018 at 15:01

While doing a steam distillation of sage, I got distracted and let my RBF boil to dryness. My hotplate was on its highest setting and the flask was insulated with foil so the heat built up quickly. What you see in the photo is the surface of my hotplate glowing a dull red with pieces of melted aluminum foil. I was impressed that my plate could get that hot but also a little worried that it might damage the flask so me in my stupidity poured water into the flask to cool it down causing it to crack from thermal shock.

differential thermal expansion ?

Sulaiman - 16-7-2018 at 07:19

I opened one of my glassware boxes and found a broken Claisen adapter,
I know that the box has not been miss-handled since last use.
When put it away the weather was cold and I left a very solid ptfe 24/29 overhead stirrer gland in the neck,
we are presently having a (relaively) hot summer.

Is it likely to be due to the difference in thermal expansion ?

JJay - 16-7-2018 at 10:06

Quote: Originally posted by Sulaiman

Is it likely to be due to the difference in thermal expansion ?

Not unless your Claisen adapter was poorly constructed, which looks likely. I had the same thing happen once at around 100 C with a very similar looking Claisen adapter. Stir bearings shouldn't break ground glass joints at temperatures associated with ordinary use.

Sulaiman - 16-7-2018 at 10:25

D'oh ! ... I am an idiot !
Of course the ptfe and glass have to work reliably at much higher temperatures/temperature changes.

The adapter does seem poorly made,
part of the joint at the junction has so many bubbles that it looks like the milky way

Not a disaster as I also have a 24/40 Claisen, but I want to replace it eventually.
I'll just write this one off as 'unknown.'

happyfooddance - 16-7-2018 at 13:21

Yeah, but at higher temperatures ptfe flows more easily... The thermal expansion is more likely to cause a joint to crack if it is assembled cold, and then brought to room temp; for example, tightening a stopcock in the freezer, and then letting it warm to room temp. Rather than operating at high heat, which makes the ptfe much less rigid.

Ptfe has a much, much larger CoE than boro.

I have lost a couple pieces this way. If ever the joint is going to be heated, I am careful not to make it too snug.

Also, when I put sep funnels in the freezer, I have to tighten the stopcock periodically as it cools, or it will leak. And loosen it as it warms up.

Also, beware chinese glass. You guys have a lot more faith in deschem and nanshin than I do! Never again nanshin for me.

CobaltChloride - 17-7-2018 at 08:26

What bad experience did you have with their glassware?

happyfooddance - 17-7-2018 at 09:19

Quote: Originally posted by CobaltChloride

What bad experience did you have with their glassware?

You get what you pay for.

I've had about a dozen pieces of cheap chinese glass, and two years later not a single piece was intact. In that two years I broke more glass than ever in my life.

The craftsmanship is terrible. Almost every piece has multiple bubbles, nothing is annealed properly... What is the point of having borosilicate if it isn't at least slightly resistant to thermal shock? I feel like if they used soda-lime glass it might be a little better quality, if not chemically inert.

But what good is chemical resistance when your flask breaks unexpectedly?

I get my glass from Laboy or Dr. Bob. Great quality, great price.

My equipment sees a lot of use, so others might have different standards... But I don't consider it saving money if the equipment fails prematurely and unexpectedly.

JJay - 17-7-2018 at 10:05

My three year old pricechopper2011 kit... let's see here... The Claisen adapter broke under a stir bearing, the Vigreux got smashed, the 250 mL flask has been replaced 3x, the sep funnel got dropped, the thermometer met a tragic end when it was sucked into a flask at high velocity under vacuum, and the Liebig was chipped by high leverage with a steel rod while cleaning. Aside from the Claisen adapter, everything broke due to accidents or abuse. I don't think I'd fare much better with American glass, but I will say that I've never broken anything I've gotten from Dr. Bob (other than the 14/10 high-temperature phenolic caps I melted).

I really don't think I break more glass than average. I clean and reuse all of my jointware, but in my view, it's basically all disposable.

[Edited on 17-7-2018 by JJay]

Follow up on broken Claisen adapter

Sulaiman - 14-8-2018 at 09:05

I ordered a new 24/29 Claisen adapter to replace my broken one, cheap Chinese as usual.
Surprisingly there were no visible bubbles in the glass,
but the glass was badly scratched so I asked for a replacement.
Today the replacement arrived - no scratches but bubbles instead

I tried to remove the broken part of my old Claisen and discovered how brittle the glass was around the joint.
I guess it was not annealed.

Heptylene - 14-8-2018 at 11:41

Goddammit! I broke by 250 ml pressure-equalizing addition funnel yesterday, in the most stupid way possible.

I was trying to purge with argon an apparatus previously under vacuum by connecting said apparatus directly to an argon cylinder. I let the gas flow in and of course the pressure got too high inside the apparatus. My addition funnel jumped from the 3 neck RBF it was connected to and fell on the groud, breaking the bottom ground glass joint in the process. I'll have to replace it soon because it is a very hand piece of equipment, that some reaction absolutely require. The two things that bug me the most with this are:
1. I KNEW this would happen but I thought I could get away with using that argon cylinder directly. Should have used a balloon to transfer the gas instead.
2. I had only used that addition funnel twice!

This happened while preparing a dry apparatus for a somewhat large scale grignard reaction (0.2 mole PhMgBr). On the upside, the reaction went extremely well even without the addition funnel. The magnesium reacted immediately with the bromobenzene, and nothing blew up or boiled over.

I also broke a 250 ml flask recently while trying to scrape a solid from inside of it. This ALWAYS happens when scraping solids from glass containers, everything else I have ever broken was when scraping something from somewhere, but I always think I can get away with it.

Spilt oxalic acid

fusso - 18-8-2018 at 06:37

Loss is ~10g even after collecting most solids that didnt touch the table :mad:

elementcollector1 - 18-8-2018 at 09:03

Recrystallize it, maybe? If you haven't already thrown it away, that is.

JJay - 18-8-2018 at 14:23

I crushed my pricechopper2011 Liebig in a clamp.

It's actually still usable if I wrap some tape around it, but I think it is time for it to retire. I really need to stop clamping things so tightly....

fusso - 24-8-2018 at 09:17

Quote: Originally posted by elementcollector1

Recrystallize it, maybe? If you haven't already thrown it away, that is.

Oxalic acid is pretty cheap so I won't bother a recrys. So I just threw it away.

weilawei - 11-9-2018 at 10:19

I'm down one 50mL beaker and I cracked the thermometer joint on my short path head. I don't usually have an issue with stuck joints, but I went with Teflon sleeves for the last project. Not my favorite, and they always cause trouble, but I don't know many great substitutes.

weilawei - 16-10-2018 at 19:02

Broke a 1L 24/40 Erlenmeyer flask tonight. Clean, but annoying. Does anyone else feel like they break more glassware the more time they spend in the lab (i.e., rate of breakage increases)? I have been spending all my non-work waking hours at the bench. Maybe that's just a cognitive bias from being more constantly exposed to it?

It sure doesn't make my wallet feel any heavier.

EDIT: I see I was the last person to post in this thread also. Doh. Man, that last post felt like last week. Where did the month go?

[Edited on 17-10-2018 by weilawei]

Elrik - 16-10-2018 at 21:12

My last losses were a 250 ml beaker that jumped off a ring stand that got stuck to the bench somehow [admittedly sloppy technique] and last month my mother went in my kitchen and broke my only 500 ml volumetric flask. Both pieces were bought by my grandfather right after he defeated hitler and entered college. Bad several weeks for 73 year old glass.

Quote: Originally posted by JJay

...the thermometer met a tragic end when it was sucked into a flask at high velocity under vacuum...

Is there any trick used to prevent that? Like electrical tape on the thermometer just above the adapter. Or is such an incident just very rare?

Sulaiman - 17-10-2018 at 05:16

Quote: Originally posted by Elrik

Quote: Originally posted by JJay

...the thermometer met a tragic end when it was sucked into a flask at high velocity under vacuum...

Is there any trick used to prevent that? Like electrical tape on the thermometer just above the adapter. Or is such an incident just very rare?

Under full vacuum the force on an 8mm diameter thermometer is about 500g,
many thermometers have smaller diameters.
So carefully pull/push the thermometer in its seal/adapter with about +/- 1 kg force to test.
At higher temperatures I do not know if the thermometer will be gripped more or less securely.

I have thermometer pockets for thermocouples, and two jointed thermometers,
partly due to my fear of vacuum-propelled thermometer accidents.

P.S. My cheap-Chinese '500ml distillation kit' came with a thermometer still head adapter,
- and a thermometer that was too thin to be gripped well.
The adapter works fine with my thicker thermometers or glass tubing
- at atmospheric pressure.

I consider it unwise to use the O-ring type thermometer adapters with vacuum.

[Edited on 17-10-2018 by Sulaiman]

Thermometer Clamp

FloridaAlchemist - 17-10-2018 at 08:21

When doing vacuum distillations I use these type of clamps to hold the thermometer in place.

DavidJR - 17-10-2018 at 14:30

Quote: Originally posted by Sulaiman

I consider it unwise to use the O-ring type thermometer adapters with vacuum.

Honestly even though I have a handful of the o-ring type adapters, I seldom ever use them. I don't like how the thermometer can wobble about.

The glass thermometer wells are just much better. You can put a mercury or spirit thermometer inside, or, as I prefer, a thermocouple probe.

weilawei - 22-10-2018 at 10:59

I usually replace the o-ring with a good wrapping of teflon--enough to really get it jammed in the thermometer adapter (which is the two-piece kind that screws around the thermometer and clamps down on it). Never had it move, though sometimes adjusting it requires taking it back out, cutting the tape, retaping it, etc..

I did, however, shoot the safety release stopper out of my setup the other night. Put a dent in the ceiling and broke the stopper in half, but no other damage or mess. Really reinforces how important good lab practice is when stuff goes sideways.

[Edited on 22-10-2018 by weilawei]

esquizete_electrolysis - 26-10-2018 at 10:53

I once was trying to make an electric stirrer and was trying to activate the magnet while the motor was going, and I was using one AC current and A DC current. Long story short, the circuits crossed and killed my power supply.

CobaltChloride - 26-10-2018 at 11:51

I was recrystallizing some benzamide (about 15g) from toluene and I accidentally knocked over the beaker. Now my 7$ hotplate is covered in a healthy layer of benzamide

. Fortunately, my hotplate stirrer should arrive and if this sort of accident happens again it should be pretty easy to clean the ceramic surface (my current hotplate has some sort of black semi-sticky surface and I'm not able to remove the benzamide at all)

Herr Haber - 7-11-2018 at 04:19

This morning I took a 2L flat bottom flask in the shower to get rid of the big Potassium sulphate cake that had settled in the bottom.

Gave a few swirls, cake separated from the bottom, turned the flask to empty the water and... crash !
The weight of the sulphate salt broke the flask.
Better now than during a distillation !

hissingnoise - 7-11-2018 at 04:36

My deepest condolences.

Next time distilling HNO₃, I'll be using the sodium salt just to see how much easier the NaHSO₄ cake is gotten rid of...

Herr Haber - 7-11-2018 at 12:17

Quote: Originally posted by hissingnoise

My deepest condolences.

Next time distilling HNO₃, I'll be using the sodium salt just to see how much easier the NaHSO₄ cake is gotten rid of...

I can answer that. I did three runs this weekend.
2 with sodium nitrate and the last one with potassium nitrate as I didnt have anymore dried sodium nitrate ready.

With sodium it took less than an hour using hot water and a few water changes. Cold water works fine, you just have to change it a few times more.
Cold water and potassium salt is well... 10 on the scale of pain.
Not much better with hot water but at least it's doing "something".

It will now become standard SOP to fill the flask with water as usual when I'm done but instead put it back on the heating element.

At least I finished dissolving the silverware that was sitting in my 3L reactor.

weilawei - 8-11-2018 at 05:33

Quote: Originally posted by Herr Haber

Quote: Originally posted by hissingnoise

My deepest condolences.

Next time distilling HNO₃, I'll be using the sodium salt just to see how much easier the NaHSO₄ cake is gotten rid of...

I simply put it in the microwave for 10 second bursts. The cake easily breaks apart with a little hot water. Done cleaning in 5 minutes instead of 50.

Herr Haber - 9-11-2018 at 04:20

This is not a good week for glassware.
Yesterday I received a small order from Deschem.
I unpacked everything and put it in the "to be cleaned" plastic bin.

Except for that little thermometer well that stayed hidden on the blanket until I went to bed and sent it around flying around the room... Bits of glass everywhere at the foot of my bed. I'm glad I didnt wake up tonight !

Abromination - 14-12-2018 at 18:50

I recently had an hydrochloric acid vapor incident in where I had generated so much without knowing it (I thought it had been consumed and it ate through a metal bit in my fume hood and forced my to leave for an hour hour two to let the room air out. That was fun.

mayko - 17-1-2019 at 09:41

Here's a fun thread about laboratory mishaps and unsettling discoveries (multiple picric acid evacuations, containers labeled only "Open this and you'll be sorry", body parts, etc)

https://twitter.com/DrMRFrancis/status/1085691863200419840

Abromination - 25-1-2019 at 15:54

Once again, another bad lab day. It was above freezing with a nice breeze outside so I decided to make today a lab day. I decided to make some sulfuric acid via the SO2 and oxidizer method. I had finished my first dropwise addition of hydrochloric acid to the sodium metabisulfite and had decided to add a bit more. I added more acid to the addition funnel and attempted to dropwise add it, although it became stuck open and all of the acid poured in at once. Instead of getting away from my gas generator, I made the second mistake of closing the stopcock. In case of a pressure build up when assembling the glassware, I had used a vacuum distillation sidearm with a stopper and a tube leading to my oxidiser which would pop out if it got to high. Here comes the third mistake: I was standing infront of the stopper. It shot out and hit me in the chest and sprayed a cloud of sulfur dioxide vapor right at me. I got a lung full of it before I got a way but was otherwise fine.
Let my ignorance and stupidity be a lesson to others.

Jackson - 25-1-2019 at 16:03

Cracked my beaker while cleaning off burnt nitrates and pushing to hard while scraping. one of my Erlenmeyer flasks cracked internally from heat shock. Like the cracking is inside the glass and doesnt actually go through the walls.

Abromination - 25-1-2019 at 16:46

Quote: Originally posted by Jackson

Cracked my beaker while cleaning off burnt nitrates and pushing to hard while scraping. one of my Erlenmeyer flasks cracked internally from heat shock. Like the cracking is inside the glass and doesnt actually go through the walls.

Even if it is only cracked internally, you no longer should use it as it could shatter.

Jackson - 25-1-2019 at 17:36

I know. I no longer use it for that reason. I might turn it into boiling chips to get some more use out of it though.

j_sum1 - 18-2-2019 at 03:36

Well I am currently at hospital waiting room with a few bits of beaker in my hand. Not too serious but a bit painful at the moment. Might need stitches. Certainly needs cleaning.

Full story of my stupidity later...

J.

Ubya - 18-2-2019 at 05:30

Quote: Originally posted by j_sum1

Well I am currently at hospital waiting room with a few bits of beaker in my hand. Not too serious but a bit painful at the moment. Might need stitches. Certainly needs cleaning.

Full story of my stupidity later...

J.

hope you can use your hand as soon as possible!

j_sum1 - 18-2-2019 at 06:35

That there is bits of beaker. The orthopedic surgeon is going digging tomorrow.

morganbw - 18-2-2019 at 08:10

Quote: Originally posted by j_sum1

That there is bits of beaker. The orthopedic surgeon is going digging tomorrow.

Good luck, looks like it may be sore for a while.

Herr Haber - 19-2-2019 at 04:40

A couple of weeks ago I broke a thermometer well that I had forgotten on my bed after unpacking.

This weekend I did it again !
There was only a slight improvement with my procedure as I waited until morning to break the thing that somehow managed to stay with me all night.

Now I have 2 thermometer wells that I can repurpose...

Ubya - 19-2-2019 at 06:17

the second one could be used as a gas takeout port

Herr Haber - 19-2-2019 at 08:35

Quote: Originally posted by Ubya

the second one could be used as a gas takeout port

That's a good possibility. In both cases I can seal in place some PTFE or VITON tubing to collect or bubble gas.

j_sum1 - 20-2-2019 at 06:17

Quote: Originally posted by j_sum1

Now out of hospital.
I refer you to The Wump Incident.

zed - 27-2-2019 at 15:00

Well, the top front burner on my electric stove, is now shot.

Was I rash, in utilizing it as the heat source, for an impromptu furnace?

I was drilling holes, in what appeared to be 10lb cast iron weight disks. I have lots of extras.

Making ring stands I was.

Drilled my holes in one plate, tapped the holes, and put together a very stable ring stand.

Next plate, just wouldn't drill out. Too hard. At least, I think that is the problem.

Reasoning that the crap iron/steel must have been incidentally hardened by quenching, I decided to anneal the plate. Thereby making it drill-able.

Just put it on the front stove element, covered it with an overturned frying pan, and cranked up the heat.

After a bit, the plate acquired a sort of dull red glow, at which point there was a small explosion and a micro-fire at the base of the heating element.

I figured the "pop" might be just some cooking oil vapor "dieseling". No big deal. But, now my front stove element has become retarded.

Not heating properly anymore. Oh, well.

https://www.ebay.com/itm/GE-Hotpoint-Kenmore-Range-Cooktop-S...

[Edited on 27-2-2019 by zed]

[Edited on 27-2-2019 by zed]

[Edited on 27-2-2019 by zed]

Herr Haber - 10-10-2019 at 04:10

Take the ammonia out of the fridge.
Pour the ammonia in an Erlenmeyer in the sun.
Stopper the Erlenmeyer.

Hear the crashing sound of the stopper falling on the ground.
Oww, another one...

Ubya - 10-10-2019 at 08:40

Quote: Originally posted by Herr Haber

Take the ammonia out of the fridge.
Pour the ammonia in an Erlenmeyer in the sun.
Stopper the Erlenmeyer.

Hear the crashing sound of the stopper falling on the ground.
Oww, another one...

I hope that only the stopper bit the dust

Buchner funnel

TheMrbunGee - 10-10-2019 at 10:25

Today I confirmed, that round things like nice 70 ml ground glass joint buchner funnel do actually roll on flat surfaces.
On the second part of experiment I learned about gravity, inertia, and properties of different materials, like glass and its literal impact on metal objects.

WhatsApp Image 2019-10-10 at 21.20.42.jpeg - 104kB

Even the ground joint cracked.

Are all 600ml beakers suicidal?

RogueRose - 12-10-2019 at 16:21

I could have sworn this thread was a sticky awhile ago. Was it and was it changed?

I've broken about 6 beakers over the last 4-5 years and 5 of them have been 600ml beakers. What's the deal with these, do they just hate life or something? Do they feel inferior to the 1000ml and just can no longer go on sitting on the shelf next to it's big brother?

So I was trying to make some liquid soap by adding water to normal potassium based soap and stirring it over low heat on my hot plate. The temp was set to ~ 2.5, and I don't think it was even hot enough to boil but hot enough to melt the soap and mix it with the water. It got a little thick so I added ~15-20ml warm water (~110-120F) and some of it touched the side of the beaker after running off the flattish top surface of the soap, and "CLINK" a nice 3.5" crack up the side and it extended underneath to about of the center of the beaker.

The temp difference couldn't have been more than about 80F, MAYBE 100F, but that even seems high. It was an expensive Pyrex brand beaker I'd used 2x before and was in perfect shape.

Is it possible that there are counterfeits out there of these things? It seems like an odd thing to counterfeit but I can't imagine real Pyrex cracking like this at such a low temp diff and so little water coming into contact with the glass. I guess I could see some of these coming from China with a fake label/brand on them, but they sell boro beakers for a very reasonable price - why not make them generic boro and put Pyrex on them - or did I maybe just get a beaker with a flaw...

Anyone else seem to have problems with 600ml's?

Sulaiman - 12-10-2019 at 17:08

Does the beaker have 'PYREX' or 'pyrex' on it ?

'PYREX' is borosilicate, 'pyrex' is toughened soda-lime glass.
'pyrex' is common in USA and also for cafetieres.
see https://en.wikipedia.org/wiki/Pyrex

P.S. I've cracked two borosilicate beakers by using them directly on electric hotplates,
use a sand, salt, water, oil or air bath.

[Edited on 13-10-2019 by Sulaiman]

RogueRose - 12-10-2019 at 18:59

Quote: Originally posted by Sulaiman

Does the beaker have 'PYREX' or 'pyrex' on it ?

'PYREX' is borosilicate, 'pyrex' is toughened soda-lime glass.
'pyrex' is common in USA and also for cafetieres.
see https://en.wikipedia.org/wiki/Pyrex

P.S. I've cracked two borosilicate beakers by using them directly on electric hotplates,
use a sand, salt, water, oil or air bath.

[Edited on 13-10-2019 by Sulaiman]

It's PYREX and I paid a pretty penny for the set of 10 beakers (my most expensive purchase so far) and it was from a science supply company, so it should be legit unless they are dealing with shady suppliers themselves.

I've dealt with the Pyrex crap many times in my early days, with hot H2SO4 non-the-less (instantaneous shattering at one point). Not fun and sure got my heart pumping. Good thing it was outside on concrete slab.

As for the hotplate, are you talking about a real ceramic top lab hot plate (with stirrer). Mine's like $650 new (got it for a steal though) so I would think it should be able to have a beaker on it.. How else am I going to use the stirring? Either way, I was holding the beaker when I poured the water in and when I moved back to the hotplate the water sloshed A LITTLE, contacted the side and CLINK. The beaker was cool enough I could hold it with my hand at the top rim so I figured there would be no way that there could be enough temp diff to crack. I haven't even bothered to clean it out yet I'm so pissed.

[Edited on 10-13-2019 by RogueRose]

Belowzero - 3-7-2020 at 10:49

After waiting 24 hours for my filtration to complete (multiple liters of highly concentrated AN solution)
I figured it was time to boil some of the solution down to start the first crystalization round.

My one and only 2L beaker containing 1.5L of the solution was placed on a hotplate and slowly heated.
I waited until it started boiling and after a few small bumbs it formed bubbles and I continued doing other things.

At that point I heard a sizzling sound , at first I thought it was a droplet that hit the hotplate from the side of the glass.
Then some more sizzling, at that point I realized what was going on , my beaker was leaking!!$@!

Hoping to be able to rescue my AN I lifted the beaker from the hotplate and yes you guessed it, the bottom fell out!!
I watched 1.5L of solution hit the hotplate where it instantly formed a densy white smoke while the rest made a mess out of my table and started leaking on other stuff.

Luckily noone was around to see a large volume of thick dense clouds of smoke leaving the space.

So I wasted nearly a kilo of my precious AN which is annoyingly hard to obtain and destroyed my one and only 2L beaker, what was supposed to be a nice relaxing session after work turned into a BAD DAY IN THE LAB :mad:

I am glad it wasnt anything dangerous, flamable or worse and eventhough this was a high quality scott duran beaker this can still happen, lessons learned.

[Edited on 3-7-2020 by Belowzero]

Refinery - 5-7-2020 at 06:34

I put a fritted filter funnel in an oven in order to drive water out of it.

Few moments later, I hear a series of cracks, like an egg is hatching with glassy sidetone, and right in front of my eyes the funnel cracked right on the rim of the frit.

It shall serve for now with patent duct tape joint until a new one arrives. I suppose I will dry them with acetone rinse after this.

arkoma - 5-7-2020 at 09:33

last week got two one pound bags of strontium nitrate and one pound of hexamine. i was going to combine the two pounds of strontium salt, except i didn't. yeah, poured a pound of St salt on top of the hexamine. glad i looked before i shook it up. taped it all up tight, and know about where the dividing line is and will deal with it when i get home (out west) by carefully slicing bag open and cutting into thirds, keeping each end.

*sigh*

CharlieA - 5-7-2020 at 16:26

Quote: Originally posted by Refinery

I put a fritted filter funnel in an oven in order to drive water out of it.

Few moments later, I hear a series of cracks, like an egg is hatching with glassy sidetone, and right in front of my eyes the funnel cracked right on the rim of the frit.

It shall serve for now with patent duct tape joint until a new one arrives. I suppose I will dry them with acetone rinse after this.

Just out of curiosity, what was the temperature of your oven? Thanks, Charlie

Refinery - 6-7-2020 at 10:11

I'm not absolutely sure, but I intended to heat it up just to drive out the water, starting from 100C. It cracked within 5 minutes on placing it there, and it was not on any metal surface or so that it could have been induced by it.

CharlieA - 6-7-2020 at 17:14

I'm just speculating ($5 word for guessing): I would start with the oven at room temperature and raise the heat slowly because I'm guessing that the frit/glass wall juncture was the problem. Heating at 40* or 50* C(or just a little above room temperature should dry glassware quickly enough. Rinsing first with acetone is a good idea, but if you then heat it you would want an explosion-proof oven...or maybe just use a blow dryer.
I guess there is also the possibility that the funnel had a small stress crack.
Thanks for the quick reply...us old farts like to talk.

Refinery - 7-7-2020 at 04:39

If dried with acetone, I would not use oven to dry it because of that. I'm wary of using oven to dry anything that could be flammable. If in a hurry, I would use heat gun.

I do suspect that it had internal stresses, because it gave up so easily and the breaking line is clean, it looks like it just came apart as two parts, not that it's broken. No offense, but it was chinese and quite cheap. Very fine looking piece of glassware, in my opinion. Borosilicate glass should withstand more temperature difference. Anyways, I won't put any fritted filters into oven never again. Too costly to order a new one every now and then, and too important part of equipment to lose. Filtering pretty much anything under gravity is just painful.

Fyndium - 18-9-2020 at 03:18

I broke my best separatory/dropper funnel today while cleaning it. Turned it to rinse and the head hit the edge of the sink and it just snapped off.

Pissed af, but even more for the fact that ordering a new one takes half eternity. There are no local suppliers and the nearest ones takes only few days less than ordering from china, but with an order of magnitude higher price tag, so it's two bad options for the lesser bad.

beta4 - 4-10-2020 at 00:52

Yesterday I dropped the stirbar in the sink while washing a flask.

itsallgoodjames - 8-10-2020 at 19:45

A few weeks ago I was putting a rubber bulb on a glass pipette. this is about the millionth time I've done it without any issues, but this time the pipette decided to shatter. That same day, I accidentally broke my last thermometer.

karlos³ - 9-10-2020 at 02:26

Quote: Originally posted by beta4

Yesterday I dropped the stirbar in the sink while washing a flask.

I do that all the time... I must have lost two dozen stirbars alone in the various toilets in my appartments so far.
When the stirbars start to become scarce, I usually screw the syphon off from the sink and find a few sticking to the metal

But the toilet? Usually I notice later that my amount of stirbars has decreased and then I remember how I flushed some lye down the drain... and my stirbar(s).
Well, I hope they get happy in the canalisation, and as in my language we call them actually "stir fishes"(Rührfische), maybe they are really happier in an aquatic environment?
When I think of this, I like to imagine them as a happy swarm of "stir fishes" of various small to medium sizes, and they are swimming happily together through the sewerage, and that makes me smile like an idiot

I know they don't miss me, but often I think "damn I need a stirbar 20 right now, but the last one has escaped down to the others!", and then I miss them somewhat

outer_limits - 9-10-2020 at 03:30

My largest one went to shower drain with 300ml of strong NaOH solution. I'm almost sure that I could retrieve it but I would need to break the ceramics on the floor to get it.

Rest my friend, you served me very well! I hope you will get a chance to stir something toxic or caustic as you loved to!

MidLifeChemist - 9-10-2020 at 15:39

My plan is to have only 1 stirbar. Then maybe I'll treat it like gold.

Texium - 9-10-2020 at 21:45

Quote: Originally posted by MidLifeChemist

My plan is to have only 1 stirbar. Then maybe I'll treat it like gold.

Trust me, you’ll want more. You’ll need different sizes if you work with various sizes of glassware, and you’ll want to have one for nasty stuff that stains, along with some that are reserved for stirring cleaner solutions.

itsallgoodjames - 9-10-2020 at 22:19

Quote: Originally posted by Texium (zts16)

Quote: Originally posted by MidLifeChemist

My plan is to have only 1 stirbar. Then maybe I'll treat it like gold.

I second this. You'll definitely want more than one

TriiodideFrog - 9-10-2020 at 23:37

You can replace stir bars with paperclips, but I would highly not recommend that as they can get noisy and oxide that form on them can contaminate your solution.

TriiodideFrog - 9-10-2020 at 23:42

Yesterday, I was holding a beaker which contained acid inside when it just broke. The acid spilled everywhere on my workbench, but luckily it was quite mild. I think the beaker cracking had to do with me putting the beaker in the microwave last week to make plasma. Poor beaker.

itsallgoodjames - 19-10-2020 at 10:41

Quote: Originally posted by JJay

the thermometer met a tragic end when it was sucked into a flask at high velocity under vacuum
[Edited on 17-7-2018 by JJay]

This exact thing happened to me yesterday, while vacuum distilling white fuming nitric acid, with a thermometer that had been purchased the day before. I guess I need to get an electronic thermocouple thermometer thing, because I seem to go through glass thermometers at an astonishing rate...

[Edited on 19-10-2020 by itsallgoodjames]

Mateo_swe - 25-10-2020 at 09:44

I had 2 filter funnels brake lately when i was cleaning them.
They broke exactly where the porous coarse filter disk is located.
But that was my own fault not being careful enough.
But i have had many things brake in shipping lately.
Filter funnel, quartz glass tubes, anti-splash adapters, lots of stuff.

10 mL bromine spill

j_sum1 - 30-10-2020 at 18:07

Enough to be both unpleasant and annoying.

I keep my bromine in ampoules between 2 and 10 mL. The ampoules are individually wrapped in packing foam and are in a lidded plastic container on a bed of sodium thiosulfate.

Today while putting some chems away I accidentally knocked the container from the second bottom shelf onto a concrete floor.

As I picked it up I noticed that the plastic lid was bulging. My immediate thought was that there was a leak in one of the ampoules.

It was then that there was a pop sound as the lid came off and there was a cloud of bromine fill the room. I held my breath and was out of the room within 2 seconds.

I had some splash onto some skin. So jumped into a shower. Skin damage is pretty superficial.

Surveying damage in lab: I sprayed the air with thiosulfate spray I keep at the entry. I have lost my largest ampoule. Some bromine was still in it. I inverted it into the bed of thiosulfate and popped the lid on. Splashes of bromine were sprinkled with thiosulfate and doused with water. The smell was uncomfortable enough that I had to leave. It may take a little while for the gas to dissipate. Then I can go back to cleaning up my messes.

Takeaways: I can probably improve my packing and storing but the concept is good. The situation could have been a whole lot worse. Thiosulfate is good to have around and easy to grab. Easy egress from the lab is a good thing to have. My painted cupboard door may bear the signs of this incident for a while.

Fyndium - 31-10-2020 at 08:15

I suggest sealing all that stuff in larg-ish ziploc bags. They are made out of polyethene or polypropene and they allow for a lot of expansion when sealed flat.

I actually seal everything in ziploc bags nowadays, including my glassware. Less noisy to store and less likely to break due to cushioning effect, and if you seal them a bit inflated, they are self-formed airbags.

j_sum1 - 1-11-2020 at 00:44

I don't think ziplocks wouls have been any better than the container I was using (press sealed honey container similar to tupperware.) Both would have popped in yhe temp/pressure conditions.

If anyone is interested, here is what a bromine splash looks like after 24 hours.

Fyndium - 1-11-2020 at 01:13

You could put neutralizing agent on bottom of the bag. It would consume the reactant gas as it was produced. Of course, with expectation that there will be no gaseous byproducts.

j_sum1 - 1-11-2020 at 03:07

Quote: Originally posted by Fyndium

You could put neutralizing agent on bottom of the bag. It would consume the reactant gas as it was produced. Of course, with expectation that there will be no gaseous byproducts.

Again, I had a bed of neutralising agent in the plastic container. And I think my plastic container is a bit more robust and has greater longevity than a zinpock bag.
The difference would come down to the bag being more likely to leak whereas the container had the lid pop off percussively.

The weak point in my system is insufficeint packaging. The tip of the offending ampoule was exposed, being a bit taller than the others. And the glass was thin there. I had recently used a couple of ampoules and so there was some rattle room in there. The very tip of the ampoule was knocked off.
Also, I should have backed off when I saw the lid bulging. It was not a good thing to go off in my hand.

That said, it is not the first time that something in my lab has gone wrong but I have been saved by packing things in small quantities and having neutralising agents right on hand.

Cou - 1-11-2020 at 10:47

My cheap $50 Zeny single stage rotary vane vacuum pump is no longer pulling a full vacuum, even after I changed the oil. Im concerned that organic vapors messed it up somehow

Fery - 1-11-2020 at 11:06

Cou - freezing trap cooled with CO2 ice + organic solvent is necessary to insert before the pump... or if someone has access to liquid N2 even better... maybe at least crushed ice + NaCl (T = -18 C) or crushed ice + CaCl2 ?

Cou - 1-11-2020 at 11:14

It's too expensive to buy a block of dry ice for just one vacuum distillation, when the rest will sublime away.

Crushed ice + NaCl could condense water vapor, but not organic solvents such as ethyl acetate. I don't know why those would damage the pump. They would just mix with the vacuum oil.

EDIT: I just checked the connections and it's probably not pulling full vacuum anymore because the plumbing tape has worn out.

[Edited on 11-1-2020 by Cou]

Fyndium - 1-11-2020 at 12:32

Use calcium chloride to bring down the cooling bath to -35C or whatever your freezer goes. It's not as efficient as fancy dry-ice-acetone-liquid helium baths, but it doesn't cost a dime either. For most amateurs, it's a fact that dry ice bath is well beyond their economics, unless they're cooking some high value stuff. As stupid as it sounds, if this is the case, in long run it could be cheaper to stock new vacuum pumps instead of dry ice. Another "benefit" is the ability to vacuum corrosive stuff.

I'm not sure how this thing works actually, but I know that CaCl2 dissolution is very exothermic, but if one could prepare a concentrated solution of it pre-cooled at freezer, and add that with solid ice blocks, should this keep the temp low?

Cou - 1-11-2020 at 12:40

Freezer only goes to -17 c.

[Edited on 11-1-2020 by Cou]

DraconicAcid - 1-11-2020 at 13:16

Not chemistry glassware, but the other night, I broke a dragon-claw-themed wine glass that my mother had given me about ten or so years ago (which she had given me to replace a similar one that she had given me ten or fifteen years prior, after my then-wife broke it). Alas.

Fyndium - 6-12-2020 at 04:24

Don't work when tired. I did a post reaction cleanup and drained the washwaters - and accidentally poured half a liter of toluene that was stripped from the reaction. I realized this only later when I was looking for the flask and saw it was alongside the washwater flasks, all cleaned and shiny. I had even placed the flask away to not mess it up with the water flasks, but apparently it was not enough.

B(a)P - 8-12-2020 at 14:13

Until today I was of the opinion that evaporating basins could take a bit of heat.
This morning I wanted to do a crude test for the percentage of sodium chlorate in a mixture of what I suspect was mostly sodium chloride.
To 1 g of the crystalline mixture I added 0.5 grams of sucrose and applied heat.
Turns out the crystalline mixture was mostly sodium chlorate and the little pile burned brightly for a couple of seconds followed by a cracking noise as my evaporating dish fell in half

Piroz - 22-12-2020 at 17:02

Two weeks ago I tried to make nitric acid by dissolving NO2 in water. NO2 was generated in steel beercans (yes, in my country some beercans are made of steel, not aluminium :cool:

) by heating anhydrous calcium nitrate in embers of charcoal. I made same experiment in April and I got liquid N2O4/NO2. Unfortunately this time calcium nitrate wasn't dehydrated properly, nitric acid formed inside and created hole. Luckily that was cold part of apparatus so I changed it into undamaged beercan and NO2 generated again. Few minutes later I had the second failure - barbecue blower that I used for glowing charcoal broken down. I decided to glow charcoal by the other way- using garbage bag and hose (an idea from last experiments), but temperature was too high and one of beercans was overheated. It created bigger hole without any hope to repair.

[Edited on 23-12-2020 by Piroz]

[Edited on 23-12-2020 by Piroz]

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