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

Bad days in the lab or with glassware?

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Lambda-Eyde - 29-3-2013 at 14:31

I just salvaged 5 heating mantles from the trash outside of the biotechnology department. They were stored outside and we've had snow on and off for a few months, so they were wet. Since they after all are heating mantles, my immediate reaction was that plugging them in at low heat would dry them. The first one (one of the 500 mL ones IIRC) functioned properly. To test it, I touched it to see if it was heating up. Of course I got a shock... A nasty experience, but what the fuck could I expect from touching unisolated resistance wire hooked up to the mains? I then proceeded to plug in one of the 1L ones. Bam, there went the fuse... Luckily it was on one of the two lines in the house with automated fuses, so I could just switch them on again. But I hadn't learned, I had to test the largest one too. BAM! The regulator caught fire, and the fuse went out again...

Only then did it dawn on me: Wet heating mantles... Is it really a good idea to send an electrical current through a bundle of resistance wire soaked with water, in order to dry it?

Sometimes I'm impressed by my own stupidity...

Magpie - 29-3-2013 at 15:30

I was setting up a 500mL mantle recently and accidentaly plugged it directly into the wall socket instead of the variac. I didn't realize it until I touched the mantle a few seconds later - ouch! I was more worried that I might have burned out the mantle than anything else. But apparently it survived. I imagine that splicing a burned out heating mantle wire might be difficult.

elementcollector1 - 29-3-2013 at 17:07

This was fairly recent, about a week ago. I was cooling a solution of sodium nitrate to extract as many crystals as possible. (Eventually, I just boiled it all the way down, got a bit more.) I placed a beaker full of the hot solution inside a beaker full of snow (oddly, it snowed last week! And there was a combination thunder/hailstorm that week as well.), and left it in the freezer to cool. Unfortunately, I left it overnight, forgetting about it.

I came back the next morning to find that the larger beaker (1000mL) had cracked. Unsurprising, really, but what was surprising was the crack itself: A perfect circle, all the way around the bottom of the beaker, leaving only the bottom surface (which made a rather nice watch glass). The snow, meanwhile, had turned to ice, and took quite a while to thaw, even inside. I suppose the smaller beaker prevented the snow from expanding when it froze, causing mechanical stress on top of thermal stress from being in the freezer so long? Anyway, it's interesting that the crack was so perfectly made.

The sodium nitrate survived just fine - decent yield, too. Next time I'll just put the hot/warm beaker in the freezer, and be done with it.

kavu - 30-3-2013 at 03:49

Quote: Originally posted by elementcollector1

Unsurprising, really, but what was surprising was the crack itself: A perfect circle, all the way around the bottom of the beaker, leaving only the bottom surface (which made a rather nice watch glass) ... Anyway, it's interesting that the crack was so perfectly made.

This has to do with how the beakers are made, the seam between the bottom and the rest of the beaker can crack open. I have encountered the exact same thing when heating water in an old 1000 ml beaker.

[Edited on 30-3-2013 by kavu]

Hexavalent - 30-3-2013 at 10:24

The first practical we did in school many years ago was to heat water to boiling using a Bunsen burner flame. An acquaintance of mine was sitting down on a stool, and lifted his hot beaker off the tripod onto the bench using tongs. Whilst he was holding it in mid-air, the bottom came off cleanly, spilling hot water all over his lap. A lesson to remember, I think.

Pyro - 30-3-2013 at 10:50

one tends to remember funny things! I rarely sit while doing chem, but when i do its on a stool so i can move away fast.
One time i was standing on my stool while getting of my lab workbench because i had installed a light bulb, it toppled over, and so did I, i landed flat on my back very lucky i wasn't hurt badly!

mayko - 10-4-2013 at 17:44

My 500 mL round bottom flask just pinged and cracked while I was steam distilling some orange peels

Dunno why

Hexavalent - 13-4-2013 at 12:29

Quote: Originally posted by Pyro

one tends to remember funny things! I rarely sit while doing chem, but when i do its on a stool so i can move away fast.
One time i was standing on my stool while getting of my lab workbench because i had installed a light bulb, it toppled over, and so did I, i landed flat on my back very lucky i wasn't hurt badly!

I was at work one night (I work at a Mexican restaurant), and the waitress had mopped the tiled floor without telling me...I slipped, landed heavily on my back, causing me to launch the glass jars I was carrying out of my hands. Amazingly, I was OK and all of the jars were intact!

Pyro - 13-4-2013 at 12:53

Lol, not lab related, but you were very lucky!
Talking about slipping, My dad waxed the floor recently, which is already very slippery varnish, now Me (and the cat) are always slipping. I went down on my ass, it really hurts! and the cat always comes tearing down the hallway and then slips and smashes into the wall!

[Edited on 13-4-2013 by Pyro]

Funkerman23 - 13-4-2013 at 19:44

what brand of glass where you using and how old do you think it was?

Quote: Originally posted by mayko

My 500 mL round bottom flask just pinged and cracked while I was steam distilling some orange peels

Dunno why

mayko - 13-4-2013 at 21:03

Quote: Originally posted by Funkerman23

what brand of glass where you using and how old do you think it was?

New synthware; the postmortem was that the flask had gone dry and heated up before I added more water. User error; derp! Next time I might try externally generated steam. I had thought that direct distillation might be easier, but maybe not.

sargent1015 - 26-6-2013 at 10:01

Did not happen to me, but my co-worker shoved a stir rod through an evacuated dewar flask. Needless to say, it imploded. Fortunately, no one was injured, but man was it loud!

sargent1015 - 27-6-2013 at 17:00

Quote: Originally posted by sargent1015

Did not happen to me, but my co-worker shoved a stir rod through an evacuated dewar flask. Needless to say, it imploded. Fortunately, no one was injured, but man was it loud!

And here is the aftermath

testimento - 30-6-2013 at 13:07

I have destroyed a shitload of boiling flasks, dropped twice an entire distilling setup(with 5000ml flasks and full length thermometers, the other had dropping funnel attached to it and everything went into fine shatters at the moment they met with the concrete floor). Another distilling setup had 3 liters of boiling sulfuric acid and other one had few liters of ether. Once I melted one steel reactor with (probably thermite reaction) too hot reaction. I also spilled a gallon of ethanol on tha table and the whole table turned into instant firestorm due to propane burner but CO2 distinguisher saved the lab pretty nicely.

Funkerman23 - 30-6-2013 at 13:19

This is a bit embarrassing but when I received my very first Laboy order I had a coiled reflux condenser. Now I don't know how the first crack formed but low and behold there was one in the middle of the coil before the days end. I wish I knew if coiled condensers are supposed to have a tiny ring to then if you lightly tap the walls or if they are supposed to be that fragile but I was heartbroken. I had planned on using that for ether( now I have a 400mm Allihn and a 600mm West for that but I haven't tried either yet so who knows if those two will do the job). 60 bucks long gone but that still stings to this day. I've been scared to order anything coiled by Laboy since..opinions on that are always welcome though.

over tightened a stopcock from them as well but that was less irritating.

sonogashira - 30-6-2013 at 13:40

I smashed the end off a 2 liter separating funnel a few days ago. It was a nice clean break at the end.

I might get a glass blower to seal it one day, then I'll be the coolest kid in town with a 2 liter pair shaped! (Unfortunately I don't know a glassblower!)

[Edited on 30-6-2013 by sonogashira]

Organikum - 30-6-2013 at 19:15

Quote: Originally posted by testimento

I have destroyed a shitload of boiling flasks, dropped twice an entire distilling setup(with 5000ml flasks and full length thermometers, the other had dropping funnel attached to it and everything went into fine shatters at the moment they met with the concrete floor). Another distilling setup had 3 liters of boiling sulfuric acid and other one had few liters of ether. Once I melted one steel reactor with (probably thermite reaction) too hot reaction. I also spilled a gallon of ethanol on tha table and the whole table turned into instant firestorm due to propane burner but CO2 distinguisher saved the lab pretty nicely.

Impressing!
Seems you dont have a learning curve but a flatline. In the case of your early demise you should donate your brain to science - maybe they are able to figure something out...

/ORG

sargent1015 - 30-6-2013 at 19:25

Quote: Originally posted by sonogashira

I smashed the end off a 2 liter separating funnel a few days ago. It was a nice clean break at the end.

I might get a glass blower to seal it one day, then I'll be the coolest kid in town with a 2 liter pair shaped! (Unfortunately I don't know a glassblower!)

[Edited on 30-6-2013 by sonogashira]

If you are near a university, most have a glassblower in the art department, or even in their Chem department. They are coveted since accidents happen a LOT in undergraduate labs. Good luck!

Broke a clamp

vmelkon - 3-7-2013 at 13:18

I broke a clamp

Has this happened to anybody before?
The clamp comes from united nuclear and looks like this one
unitednuclear.com/index.php?main_page=product_info&cPath=25_30&products_id=340

I was undoing the back screw to remove it from the stand. The thick metal part of the base broke. It metal surface of the broken face reminds me if carbon steel but I don't think it is carbon steel. It is perhaps a zinc alloy.

Damn. Now I'm down to one

Sublimatus - 3-7-2013 at 13:43

The only clamp I ever broke was just that same design. I simply overtightened it.

I'm not so keen on that design. I've come to prefer the three-fingered type. I like the kind with a screw for each side, but the single screw type is serviceable as well.

Mailinmypocket - 3-7-2013 at 14:12

60$ thermometer... Enough said

bfesser - 3-7-2013 at 15:52

Recover that mercury! My condolences on your thermometer, <strong>Mailinmypocket</strong>. What type was it?

Mailinmypocket - 3-7-2013 at 16:31

Quote: Originally posted by bfesser

Recover that mercury! My condolences on your thermometer, <strong>Mailinmypocket</strong>. What type was it?

The mercury was my main priority

it was a -1- 201c in 0.2c increment thermometer... No idea what happened, I knocked it accidentally on the hotplate and it went *tink* and the bulb broke clean off.

testimento - 3-7-2013 at 23:54

Well, fuck.

Think it's time to replace all the similar clamps from my lab before something catastrophic happens. Hanging 10- and 20-liter flasks full of highly corrosive, toxic and flammable +1g/cm3 liquids supported by those crap-clamps is not a good idea after all.

Endimion17 - 4-7-2013 at 05:14

I know those clamps. Crappy and worthless pieces of equipment capable of holding only the lightest stuff in situations where it will never encounter any corrosive fumes.
You don't make a clamp from zinc alloy profiled sheet. It's destined to fail shortly.
The best clamps I've ever encountered and managed to buy are either cast stainless steel or brass ones. They can last a lifetime if properly maintained.

When you buy clamps, forget about this pressed sheet crap. It's being sold for the same, if not higher, price as cast clamps - just because they're laboratory clamps. It's a rip off.

froot - 4-7-2013 at 05:30

I've had a similar experience with a very similar looking cheap cast Zinc-like clamp. It appeared to me like it failed from chemical attack. As soon as they have been exposed to corrosive fumes I would not dare use them for anything risky/expensive.
It might help to spray them with a coat of clear enamel to try prevent corrosion.

vmelkon - 4-7-2013 at 07:47

Here is a picture.
I tested with a rare earth magnet and it isn't magnetic. I know that this isn't a definite proof that it isn't steel.
The back screw is magnetic.
I'm thinking about making the part from lead.

[Edited on 4-7-2013 by vmelkon]

[<a href="u2u.php?action=send&username=bfesser">bfesser</a>: merging threads]

[Edited on 7/8/13 by bfesser]

bfesser - 4-7-2013 at 07:56

It's worth noting that high quality stainless steel (such as that used in good commercial kitchen equipment, or nice Swiss anti-magnetic tweezers) won't significantly attract a rare earth magnet—I know this from personal experience. Still, that looks like zinc to me. I hate that design of clamp (the one-piece type 'universal' type.) In my experience, nothing beats the three finger type with a solid boss-head. I have dozens of clamps and boss-heads like those pictured:
<img src="http://orgchem.colorado.edu/Technique/Equipment/Images/Clamp3prong.jpg" />
The older clamps are better (corrosion isn't really a concern). Construction was more solid, they didn't skimp on alloys, and the machining was of better quality. I also prefer the domestically produced ones (USA, in my case), not the cheap imported Chinese shite.

[Edited on 7/8/13 by bfesser]

mr.crow - 4-7-2013 at 10:59

Why are clamps such cheap metal? I broke a brand new one, but the liquid nitrogen probably helped! You could see all the crystal domains in the broken metal.

watson.fawkes - 4-7-2013 at 12:11

Quote: Originally posted by mr.crow

Why are clamps such cheap metal?

Plenty of folks don't need high quality metal. If your business is, say, an environmental testing lab, you're not going to be putting your gear under the same stress as in a research lab.

Organikum - 4-7-2013 at 13:15

Quote: Originally posted by vmelkon

Here is a picture.
I tested with a rare earth magnet and it isn't magnetic. I know that this isn't a definite proof that it isn't steel.
The back screw is magnetic.
I'm thinking about making the part from lead.

[Edited on 4-7-2013 by vmelkon]

Naaa...
Just glue it with a good 2-component epoxy. It will not break where its glued, that being probably the strongest part then

Had exactly the same problem twice. Glued. Holds perfect.

The material is high-pressure die casted zinc, whats a zinc alloy of some kind and truely cheap shit not worth a penny.

regards
/ORG

[<a href="u2u.php?action=send&username=bfesser">bfesser</a>: merging threads]

[Edited on 7/8/13 by bfesser]

confused - 4-7-2013 at 17:06

i second the epoxy

Acidum - 5-7-2013 at 12:25

Quote: Originally posted by sargent1015

Did not happen to me, but my co-worker shoved a stir rod through an evacuated dewar flask. Needless to say, it imploded. Fortunately, no one was injured, but man was it loud!

And here is the aftermath

We had very similar problem at science/chemistry popularization show, when a young colleague of mine touched dewar filled with liquid nitrogen with glass beaker filled with hot water from which he poured it gently to produce water vapour fog. Bunch of small kids were all around the table (many of them leaning their heads on it), quite lot of fog emanating from dewar, and all the sudden BANG and entire table is engulfed in thick white fog! At first nobody realized what happened, parents started to freak out, kids looking at us believing that this is all part of experiment, and when the mist dissipated entire table was covered with glass shatters - and nobody got hurt!
...off course, we instantly removed young chemist from the table, cleared the mess, and put improvised fence meter from table...

DutchChemistryBox - 8-8-2013 at 03:11

I had bought a three-neck 500ml rbf on a second hand sales site for 20 euro. Due to a miscommunication he thought that I wanted all his rbf's.
So I've also got a four-neck 1l rbf and a five-neck 6l rbf. Unfortunately 1 neck of the big flask broke during the shipping.

I think that I'm going to fix it with glue and use it as decoration. Maybe a glassblower can fix it so I can sell it.

[Edited on 8-8-2013 by DutchChemistryBox]

Lambda-Eyde - 8-8-2013 at 03:54

How much would you charge for the broken 6L flask?

prof_genius - 8-8-2013 at 05:23

Quote: Originally posted by DutchChemistryBox

I had bought a three-neck 500ml rbf on a second hand sales site for 20 euro. Due to a miscommunication he thought that I wanted all his rbf's.
So I've also got a four-neck 1l rbf and a five-neck 6l rbf. Unfortunately 1 neck of the big flask broke during the shipping.

I think that I'm going to fix it with glue and use it as decoration. Maybe a glassblower can fix it so I can sell it.

[Edited on 8-8-2013 by DutchChemistryBox]

What second hand site did you get it from?

[Edited on 8-8-2013 by prof_genius]

DutchChemistryBox - 8-8-2013 at 05:36

@Lambda-Eyde
If you are interested in it you can send me a U2U.

@prof_genius
I've got it from www.marktplaats.nl
According to the seller they're old rbf's of DSM

subsecret - 8-8-2013 at 09:20

I can't remember breaking anything in my lab... Though I once did spill some HCl on one of my clamps (Aluminium I think) and it still has spots of AlCl₃.

One time at school, some kid was playing with a steal ball which he proceeded to drop into a beaker on a hot plate. Luckily it was only being used as a hot water bath...

On a separate occasion, someone stuck their head in a Bunsen burner, promptly loosing an eyebrow.

Don't ask me why...

Mailinmypocket - 8-8-2013 at 10:34

A co-worker once decided to check how much gas was left in a lecture bottle by "opening it a bit to see" the thing is that it was a new cylinder and had a red cap on the end. Thankfully it was only nitrogen, but the red cap flew off at such speed that it hit me on the cheek and made a red welt, I could have gotten an eye injury. Stupid dummy... Doesn't work there anymore as far as I know. I wonder why. Who does a thing like that!?

Red cap like this:

phlogiston - 20-8-2013 at 14:19

A fellow student was refluxing a large volume (several liters) of a mixture of acetone and diethylether under reduced pressure when suddenly for reasons that remain unexplained the roundbottom flask broke, spilling all of its contents in one big flood. Much of it gushed out of the fume hood (there was only a small ridge) onto his legs. It was warm, but not so that it burned him painfully. However, this being the 90's and he being a lover of hardcore house music, he was wearing synthetic pants and shoes typical for the subculture:

They were called 'gabber' in Dutch. To our amusement, his pants dissolved rapidly, leaving only a few mushy strips of fabric on his legs and a sticky mess of what used to be his shoes. He walked around the rest of the day in his underwear, with a long labcoat over that. A friend went home to fetch new clothes. Fortunately, no fires, no injuries and we all learned a lesson on safety.

[Edited on 20-8-2013 by phlogiston]

elementcollector1 - 22-8-2013 at 12:58

Broke 2 RBF's in as many days - this last one full of acetone! I managed to save some of it, but still...
I'm keeping the broken glass in case I need it for something (or figure out how to fix it), but do any of you do the same?

Praxichys - 23-8-2013 at 11:57

I have had many mishaps over the years, some more notable than others.

The first one I can remember is the time I was in the second grade and I was already intersted in chemistry. I would bring small (~50mL) glass jam jars full of "chemicals" (flour, water, vinegar, salt, etc.) to school in a large palstic bag my mother had generously provided for me, to be mixed on the playground to amuse my friends. This ended one day as the bag touched the ground as I was swinging it rather carelessly in the hallway, causing the jars to break and the CO2 evolved to inflate the bag, causing no small amount of alarm.... that practice ended quickly. Luckily, this was before one was classified as a miniature domestic terrorist for such activities.

The second mishap I can remember is pouring about 25mL of mineral oil onto my first hotplate after having assumed "fog machine oil" I had previously encountered was actually common mineral oil (erroneus, I later found out. It's glycerine.) Turns out it makes one heck of a lot of persistent white smoke anyway, which proceeded to fill my parent's basement, much to their unamusement.

The third incident involves an attempt to melt moth balls in an effort to blend them into candle wax to make a candle that would (hopefully) kill moths. Molten naphalene, as it happens (these were the days before p-dichlorobenzene was popular), has quite a vapor pressure. The house was evacuated for a good hour to let things air out. However, every moth within a five mile radius must have died at this point. I think I was about 10 years of age.

A fourth incident occured as I was melting lead and an old roll of solder in a beaker on my hot plate, as I had routinely done many times before. Instead of casting it, I decided to make an ingot by letting it cool in the beaker. After cooling, it proved to be very difficult to remove from the beaker. A few whacks to the overturned container freed the chunk of metal... and also the bottom of the beaker. Whoops.

In my first year of college, I had managed to find both concentrated sulfuric acid and ammonium nitrate at the local hardware store off campus. Having always yearned for the coveted nitration mixture (and unfortunately having used organic peroxides before then) I decided to try making a small mixed acid batch just to ascertain its properties and maybe nitrate a few cotton balls. This was in lieu of waiting a week to take it home the the lab proper, which was still located in my parent's basement. I carefully cooled and mixed the two chemicals, and, noticing the peculiar fuming that happens above such a mix in a humid environment, wafted some into my nose and took a breath. I nearly passed out. I distinctly remember the horrifying and rapid onset of tunnel vision as I scrambled to put the glass somewhere where I would no longer be exposed to its fumes. I regained a shaky but lucid composure rapidly and eneded up disposing of it in the bathtub with copious amunts of water. I had lots of fun with nitration reactions that summer.

I also remember a time when I had melted a hundred or so grams of sodium hydroxide in a low, round food can. I was experimenting its extraordinarily corrosive effects on various materials when I managed to get a drop of it on my forearm. I had a crater in my arm for a few months which has gradually turned into a small red scar.

Before I moved out of my parents house I managed to burn the lawn many times with overzealous thermite experiments. The worst incident involved the unforseen fallout from an ash cloud generated by a manganese-based thermite composition. This left the nearby concrete driveway leopard-spotted with perminant tan stains of MnO₂. My father was not pleased in the slightest.

Borosillicate microwave oven platters are a blessing and a curse. I have disassembled many, many goodwill-store microwaves for experiments, and I often work over these glass plates to save my wooden benches from errant drops of sulfuric acid and other things which don't get along with plywood. They are rather nice - unreactive, and can take a spill of about 250ml without overflowing. Unfortunately, though many beakers and flasks will survive if dropped on plywood from a short distance, dropping them onto a heavy glass plate makes for almost certain breakage. I lost many pieces of my old 19/22 set in this manner. Luckily, I learned many lessons with the cheaper, smaller glassware before I sold the lot of it and upgraded to 24/40.

My latest mishap is not so bad, just a few polyacetal keck clips being reduced to a crumbly powder due to exposure to hot nitric acid vapor during a routine liter-sized synth to replenish my stock of 68%. Luckily, they are cheap, and a lot of ebay sellers will throw them into a glass kit for free in place of a glass stopper or two (of which I already have too many to be useful).

malford - 26-8-2013 at 19:14

Quick question: order these companies in quality (consistency of size, shape, thickness) and straightness -- Corning Pyrex, Wilmad-LabGlass, Chemglass. Is there much of a difference?

Variscite - 26-8-2013 at 21:00

I know Chemglass is usually very thick, best suited for a mantle or some other slow heating method.

Dr.Bob - 27-8-2013 at 05:14

Quote: Originally posted by malford

Quick question: order these companies in quality (consistency of size, shape, thickness) and straightness -- Corning Pyrex, Wilmad-LabGlass, Chemglass. Is there much of a difference?

Pyrex is still good stuff, but they are not as easy to find anymore, or as consistant. Much of their stuff is now made in Europe, so it costs more than others in some cases. ChemGlass seems to be the best now, with a good online catalog, and LabGlass is also good, and Kimble/Kontes is also still OK. Another one I still like is Ace, they have a good online catalog as well, which is very helpful given how complex some of the glassware is.

The Chemglass thick-walled flasks are the heaviest walls of any glassware I have ever seen, great for sturdiness, bad for heating harshly, as they will crack from heat stress if abused.

prof_genius - 4-9-2013 at 08:04

I remember once i was showing off my lab glass and dropped a 250ml beaker.

Plutonium239 - 4-9-2013 at 13:43

Yesterday I mixed some sodium hypochlorite and muriatic acid in an antique volumetric flask. So much gas was produced that the glass stopper was blown off and hit the wall, but everything was OK. I guess I should have done some stoichiometry.

MichiganMadScientist - 4-9-2013 at 15:59

Quote: Originally posted by Plutonium239

Yesterday I mixed some sodium hypochlorite and muriatic acid in an antique volumetric flask. So much gas was produced that the glass stopper was blown off and hit the wall, but everything was OK. I guess I should have done some stoichiometry.

Just curious: What exactly were you trying to accomplish by doing this?

As for me, my worst lab accident was when I had a rather large HDPE bottle containing conc. HNO3 leak out. I had stored the bottle inside a rubbermade tub full of various equipment, which promptly rusted from the fumes.

But here's the crazy part: I also had assorted glassware in that same rubbermade tub. I had wrapped the glassware in a bunch of old cloth rags/tshirts to preventage breakage. The fumes were so crazy they literally reduced the rags to shreds of powdery fabric...

[Edited on 5-9-2013 by MichiganMadScientist]

Metacelsus - 5-9-2013 at 04:50

The same thing happened to me when I was working with aqua regia. I picked up a rag that I had nearby, and it just disintegrated.

12AX7 - 5-9-2013 at 11:03

Lucky those rags didn't also catch fire!

I've had sulfuric acid residue decompose rags (paper towel rags, to be exact). Example: filtering crystals away from acidic supernatant. Crystals are rinsed and dried; rags are rinsed several times and allowed to dry (reduce, reuse, recycle!). After weeks, the rags range from weak to crumbling. This is, of course, something sulfuric acid is very good at.

Tim

Pyro - 5-9-2013 at 11:43

how about those little black dots on wood tables?

Ever had a towel in a certain place inside for about 6 months, and then next time you pick it up it completely falls apart?

Pyro - 8-9-2013 at 08:08

Today I used the last of my 1l bottle of H2SO4, so I got a funnel and my big refill bottle (2,5l) and started to refill the small one, everything went well until air started escaping from the funnel, splattering drops of H2SO4, one of which landed on my chin, the other on the tip of my nose. it immediately tarted burning so I quickly wiped the most off with my sleeve, then stripped off my gloves and rinsed it with water.

now I have 2 red blotches on my face, lucky it didn't get under my glasses!

sonogashira - 8-9-2013 at 11:05

Goodness. Probably you didn't have a gap between the neck of the bottle and the funnel?

Pyro - 8-9-2013 at 12:46

nope, the narrow bit of my funnel has a groove in it for just that, but the bottle opening was too big, so the funnel rested where there was no groove

Pyro - 24-9-2013 at 06:25

today at school we had to test different foods for fat content by putting them in a test tube with some ether, then evaporating the ether on a piece of paper to see if it leaves grease behind.

anyway, some idiot girl dropped a pasteur pipette into the bottle! (it was a brand new bottle, just opened) I took a big flask from the cabinet and poured the ether into it, then retrieved the now bulbless pipette, all that was left of the bulb was a little sticky ring of rubber.

I'll tell you, we are very privileged to have our own labs with nobody else! working with 20 uncoordinated people is hard, especially if they are dumbwits!

Metacelsus - 30-9-2013 at 11:57

Yesterday I learned just what happens if you use the wrong kind of vacuum pump for corrosive gases. It stopped working, so I opened it up to find this:

Luckily, I was able to scrape the rust off and get it working again.
Also, a bromine burn I got a few weeks ago when an ampule cracked from heat stress as I was sealing it:

The burned area turned brown and the outer layer of skin evenutally flaked off (I'm fine now, no scarring or anything

)

Mailinmypocket - 30-9-2013 at 12:01

I was making an azo dye today and severely stained my lab floor

now there is a blood red splat mark...

Bot0nist - 30-9-2013 at 12:01

Damn! Sorry for your misfortune CC. Be careful!

[Edited on 30-9-2013 by Bot0nist]

Mesa - 30-9-2013 at 13:04

A few days ago a (lit) alcohol burner broke in my hand, splashing it with ethanol and subsequently setting it alight. There was still quite a bit of ethanol left in the burner so instead of dropping it and putting out the fire on my hand, I walked over to the bench and set it down in a large tub of sand, then put out my hand with a rag. It's surprisingly difficult to quash the instinctive reaction to being burnt, but the thought of starting a larger fire in my newly set up lab was quite motivating.

Earlier today, I managed to de-glove my index finger of the burnt hand while tying my shoelaces. It was/is much more painful than the burn itself was.

DrSchnufflez - 30-9-2013 at 21:15

I had my virtually unused 1 liter three neck RBf shatter on me

Funkerman23 - 30-9-2013 at 21:33

Looks like one of those Harbor Freight pumps( my apologies if this is not the case) but Good Lord, what have you been doing to that poor pump?Yechh!

Quote: Originally posted by Cheddite Cheese

Yesterday I learned just what happens if you use the wrong kind of vacuum pump for corrosive gases. It stopped working, so I opened it up to find this:

Luckily, I was able to scrape the rust off and get it working again.
Also, a bromine burn I got a few weeks ago when an ampule cracked from heat stress as I was sealing it:

The burned area turned brown and the outer layer of skin evenutally flaked off (I'm fine now, no scarring or anything

)

stoichiometric_steve - 1-10-2013 at 15:48

i just spilled half a kilo of sodium hydroxide pellets, those two and a half hours of cleaning up the whole floor, fridge top, the brand new sartorius scale as well as the refractometer was really fun, gonna do it again that way!

bismuthate - 1-10-2013 at 16:01

i have a large black blotch on my thumb from spilling AgNO3.
I accedentally spilled acetone/ethanol on a hardwood desk. it now has a horrible giant white mark.

Metacelsus - 1-10-2013 at 17:27

Quote: Originally posted by Funkerman23

Looks like one of those Harbor Freight pumps( my apologies if this is not the case) but Good Lord, what have you been doing to that poor pump?Yechh!

Yes, it is a Harbor Freight pump. I've mostly been using it for vacuum distillation lately, with some vacuum filtration as well. I think the rust had accumulated over several months, from stray bits of corrosive gases (NO_x, HCl, etc.) that got past the trap.

Pyro - 26-10-2013 at 02:31

2 months ago I did my last Br2 batch, 500ml addition funnel on a 1l RBF, after I added the H2SO4 I got called home.
I intended to come back the next day, but the Romanians came back and I couldn't get in anymore as they changed the lock.

I got back there for the first time since then, Now I have a 1l RBF with a 500ml pressure equalized Add. funnel, and the joint is frozen! whats wore is, I was gently twisting it and I cracked the sidearm!

Ideas to separate the joint?

stoichiometric_steve - 26-10-2013 at 03:00

Quote: Originally posted by Pyro

I intended to come back the next day, but the Romanians came back and I couldn't get in anymore as they changed the lock.

WHADDAFACK?

Pyro - 26-10-2013 at 08:53

yep,
I use the cellar, but the Romanians moved in the rest of the building and changed the lock to the outer door.
And they have a key to the cellar! I wouldn't be surprised if they have being stealing my meth! OOPS, I shouldn't have said that

but does anybody have ideas to separate them? maybe something to put on the joint?

ParadoxChem126 - 26-10-2013 at 22:54

To separate the ground glass joint:

http://www.sciencemadness.org/talk/viewthread.php?tid=9251

DutchChemistryBox - 30-10-2013 at 10:20

I broke a 1 liter round bottom flask at school today.

We had to determine the concentration of caffeine in coffee with HPLC, we wanted to extract the caffeine out of the coffee with a soxhlet extractor.
My partner didn't add enough solvent to the rbf so there was not enough solvent in the chamber to empty it, when we noticed this we added more solvent(at room temperature).
Dumb, we forget to remove the heating mantle, so due to the thermo-shock the flask broke.

We already had thrown away our stock solutions for the HPLC (don't ask me why), so now we can start al over again.

[Edited on 30-10-2013 by DutchChemistryBox]

chemrox - 8-11-2013 at 14:06

I was on my way to an opera and was wearing my favorite suit. I stopped by the lab on my way and decanted some HCl for the following mornings activities. I put on my lab coat and was extra careful. nevertheless I still had to buy a new suit. I usually have some pants in the lab I don't need to keep whole. I just didn't take the time to change. More recently I made an acyl halide but didn't hook up the gas line that goes to the hood for such reax when they're not done in the hood. (an inverted funnel over a beaker of water works too and the funnel doesn't have to touch the water. Indeed it shouldn't.)

Pyro - 8-11-2013 at 14:27

Oh no, bad luck.

Just this Wednesday I ruined a nice pair of tan pants.
My partner had just made something using H2SO4. He returned the bottle to the closet.
Later I needed H2SO4 and HNO3 for nitrobenzene so I went to the chemical closet and got both bottles at once (each 1l) and walked to the work table.
When I was nearly there my partner said:''holy shit, there's sulfuric acid all over you!'', it turn out he cross threaded the cap and it had trickled out sulfuric acid. There was a line on the floor from the chem. locker to the work bench. I immediately took off my shoe and sock (luckily it was only on one leg) and rinsed with water, then rubbed in NaHCO3. My shoe survived it and looks normal after a polish, but my trousers have big white streaks on them

then later that day we were removing the acid from nitrobenzene by shaking it with water. but when we vented the sep funnel it spat a little nitrobenzene. to stop it getting all over the lab I held a paper towel in front of it. This was while the suction tube was going at full blast, I said to my partner:''oh no, could you imagine if this got sucked up the tube!'' and before I finished the sentence it slipped from my hand into the tube. In building it I had been quite liberal with the tape. I had to remove it all to get out the paper towel.

more coming soon inevitably since I have discovered a way to convert about 100g RP to WP at once

Why the Lab Power Switch Smells like Onions

Praxichys - 11-11-2013 at 07:53

I was running a routine HNO₃ synthesis yesterday with KNO₃ and H₂SO₄. This was on a fairly large scale, to produce 500mL 68% HNO₃ starting with 720g KNO₃ and 400g 93% H₂SO₄.

Everything was charged into a 1L-2-neck RBF and heating began. The contents melted into a liquid as usual and I began magnetic stirring as it slowly came to a boil. HNO₃ began collecting in the recieving flask.

After about 40 minutes of hungrily watching nothing happen, I (foolishly!) decided it was proceeding predictably enough to go upstairs for five minutes and get a head-start preparing dinner.

Three cuts into an onion, I heard a *thwack* noise somewhere in the vicinity of the lab ceiling which is below the kitchen, followed by a faint hiss. This caused me no small amount of alarm; the hair on the back of my neck stood on end as I dropped the knife at once and immediately rushed downstairs, trying not to touch the walls with my onion-juice laden hands.

To my horror, there was a glass stopper on the floor, apparently having just rolled out of the laboratory door, and it was fuming heavily in the air! I went into the lab to find quite a scene... The contents of the recieving flask were translucent white with K₂SO₄ or KHSO₄ or maybe KNO₃. There was a stalactite of this material hanging from the condenser into the recieving flask, and the condenser appeared to be totally plugged with solid white material. Worse yet, voilent boiling was taking place in the boiling flask, sending a volcano of hot foam straight up the still head, past the plugged condenser, and out the hole where the only unclipped stopper used to be, pouring heavily fuming HNO₃/H₂SO₄/K₂SO₄ straight down the side of it all and right into my heating mantle!

Luckily the fume hood was on and the air quality in the room was fine despite the clouds of brown NO_x rolling out of the top of the still head. I immediately cut the power to the lab and carefully monitored the setup as it cooled. The table gradually developed black spots from spattered H₂SO₄ during this time.

Much to my further dismay, as the mixture cooled, I heard a really loud *TIC* like cracking glass, causing me to sweat for 30 more minutes as it cooled, wondering what could be broken.

I disassembled everything once cool, except the still head, condenser, and boiling flask which are firmly cemented together by the hard white material. My stir bar is also solidified in a chunk of the same stuff. Hopefully soaking in HCl will remedy this. The worst part is that my fears of cracked glass were realized as I discovered a roughly circular crack circumnavigating the bottom of my 1L 2-neck RBF. :mad:

It could have been worse, though. The mantle appears OK, and at least the flask had the good grace to contain its contents despite the crack. I'm also glad I always leave one glass stopper unclipped on the boiling side of my distillation setup. The otherwise high pressure and weak flask could have resulted in a catastrophic explosion, probably destroying the mantle with hot acid. The blown-out stopper was surprisingly undamaged.

I think the bulk of the HNO₃ is recoverable. About 650mL of liquid (now with large chunks of highly crystalline white solid and under a brown blanket of NO_x) remained in the recieving flask. Hopefully a little dillution followed by simple distillation at the 121°C azeotrope of HNO₃ can recover something of a decent yield.

Lessons learned:
Even if you have run a reaction multiple times, there is NO excuse to leave something like this unattended. Eat before starting an experiment. Bring a book, call your mom, mess with the girlfriend, plot your takeover of humanity... just DON'T leave the lab! Always leave a pressure-release stopper on the boiling side of a distillation setup. Even when no significant vapors are produced, it is a good idea to leave the fume hood running if there is a potential for this to happen.

My best failure analysis estimates that as the HNO₃ left the flask, the K₂SO₄/H₂SO₄ mixture became increasingly more concentrated, and thereby more viscous, which contributed to excessive foaming. Unattended, the foam was allowed into the condenser. As the foam cooled in the condenser, the K₂SO₄ and any KNO₃ crystallized out, first forming large chunks in the recieving flask, the stalactite, and then clogging the condenser. The pressure buildup behind the clogged condenser then blew out the stopper, and the suddenly reduced pressure violently increased the rate of boiling, causing the foamy "volcano". The *thwack* noise was the sudden pressure release by the stopper leaving the apparatus and possibly striking the ceiling/table.

The crack might just be because this was a cheap Chinese RBF. The flask was cooling in the mantle, nice and slowly.

[Edited on 11-11-2013 by Praxichys]

zenosx - 11-11-2013 at 17:25

Ouch Prax, reminder for me to never leave the lab unattended (again, I have had my days, none that bad however). Luckily the worst for me lately was picking up a beaker of re-crystallizing AgNO3 which somehow had found its way all over the outside of the beaker. I didn't notice until washing up a few minutes later that I noticed a long streak of black starting at my first finger and running down both sides of my hand. People at school for some reason thought it was some horrible cut or something

It took about 2 weeks to finally remove the last traces of the stain.

What a shame...

*FWOOSH* - 12-11-2013 at 20:34

Had some awful glassware luck yesterday. Along with some other glassware, transporting a brand new Chemglass Schlenk-Line with 24/40 ground joints and stopcocks and a 4-neck 12L RBF and I got into a car accident. Both are toast. That 12L flask was beautiful....

@prax
I did something similar a few months back, left my HNO3 distillation running while I walked to the corner store to get a soda. 'Bout halfway there I started getting a bad feeling about the whole thing so I turned around and started sprinting back. As I was running back I see two fire trucks race past me sirens blaring towards the house. They ended up going past it, but I didn't stop running anyway.
I got back and found that my distillation had indeed popped a stopper and flooded the surroundings with nitric acid vapors, thankfully it had been under vacuum so it wasn't hot enough to produce much NOx decomp.

[Edited on 13-11-2013 by *FWOOSH*]

[Edited on 13-11-2013 by *FWOOSH*]

ruined magnets

quantumchromodynamics - 12-11-2013 at 23:21

I just discovered a very unexpected and stupid thing that I did. I managed to spill a significant amount of ferromagnetic fluid onto an N50 magnet. As you can imagine the fluid is super stuck onto the poles. An N50 magnet is just ridiculously strong. It seems impossible to get the fluid off the magnet. You can't exactly grab onto the fluid and pull it off. You also can't heat up the magnet or it ruins the magnet. I was extremely angry when I first noticed my situation, but after a few minutes I started to cry.

How fast can a person ruin a very expensive magnet? When I get a good photo I will attach it. Other folks may find a photo of this particular stupidity entertaining.

confused - 12-11-2013 at 23:42

just throwing out an idea, maybe soak up the fluid with an absorbant material? or stick it in a vacuum desicator and see what happens?

UnintentionalChaos - 13-11-2013 at 00:40

Depending if the ferrofluid or aqueous, you could try washing it with kerosene/hexanes/etc or hot water to remove the fluid component. I suspect you will still have magnetite particles stuck to it. Perhaps warm oxalic acid solution will reduce and dissolve the extremely high surface area material. while probably not (or only minimally) doing any damage to the (probably) nickel plating on the outside.

watson.fawkes - 13-11-2013 at 06:36

Quote: Originally posted by quantumchromodynamics

You also can't heat up the magnet or it ruins the magnet.

If it cools down through its Curie point in the presence of a reasonably strong magnetic field, the (microscopic) magnetic domains will lock in alignment and you'll get a functional (macroscopic) magnet back.

confused - 13-11-2013 at 08:12

wouldn't that require a very strong electromagnetic field, aslo, would that get the magnet back to its original strength?

watson.fawkes - 13-11-2013 at 11:58

Quote: Originally posted by confused

wouldn't that require a very strong electromagnetic field, aslo, would that get the magnet back to its original strength?

The minimum energy configuration for a magnet in an external magnetic field is to be aligned with it. Opposing alignment is thermal motion. If the external magnetic field is to weak, it has little effect over thermal motion. Once the external magnetic field is strong enough to push most of the magnetic domains into alignment, further field strength has ever diminishing returns.

As for "original" strength, you know that these materials are first manufactured as chemicals, then formed, and then finally magnetized, right? How do you suppose they become magnetic otherwise?

heating neo magents

quantumchromodynamics - 13-11-2013 at 18:08

Thanks for suggestions. Good thoughts...

Heating a neodymium magnet is a bit different from heating a regular iron magnet. A neodymium magnet has a powder core inside with only a thin metallic coating on the outside. They are easily ruined even by mild heating.

If one "scientifically" tosses two neodymium magnets into the air (preferably with the lights out) they collide and smash emitting brilliant sparks. This experiment is interesting because each of the fragments remains magnetic and so the system stays clumped together even after many energetic collisions. If one recursively performs this experiment using fragments as input, eventually one is left with an entertaining glob of pulverized magnetic dust. Pressing the dust into a shape and gently heating on a hotplate yields ... non-magnetic detritus.

watson.fawkes - 13-11-2013 at 19:58

Quote: Originally posted by quantumchromodynamics

neodymium magnet has a powder core inside with only a thin metallic coating on the outside. They are easily ruined even by mild heating.

That very much depends on how they're manufactured. Are you referring to a sintered or bonded magnet? Cheap magnets manufactured with barely acceptable practices would act this way, but it's not a property of Nd magents as such.

cheap neody

quantumchromodynamics - 13-11-2013 at 23:16

Mine are N50 from K&J Magnetics on this spec sheet

http://www.kjmagnetics.com/specs.asp

To my knowledge and experience neodymium magnets all have the property where they loose their magnetization if they are even mildly heated. What really happens is the magnets become useless if heated over about 80C, not even near Curie temperatures. The "hi temperature" magnets don't work much better.

From the K&J site FAQ:

21. Do I have to worry about temperature with neodymium magnets?

Yes. Neodymium Iron Boron magnets are sensitive to heat. If a magnet heated above its maximum operating temperature (176°F (80°C) for standard N grades) the magnet will permanently lose a fraction of its magnetic strength. If they are heated above their Curie temperature (590°F (310°C) for standard N grades), they will lose all of their magnetic properties. Different grades of neodymium different maximum operating and Curie temperatures. See our Neodymium Magnet Specifications Page for more details. We do stock a range of high temperature magnets, which you can see here.

Does anyone know of better neodymium magnets that can survive a bit of heat?

DJF90 - 13-11-2013 at 23:38

Samarium-cobalt (SmCo) magnets are designed for high temperature operation. They're supposed to be not quite as strong as "neodymium" magnets but retain their magnetism even at elevated temperatures.

blargish - 30-11-2013 at 16:19

Dropped my 500 mL 24/40 ground glass RBF today

. It was the only one that I had... I'm not in the greatest of moods

[Edited on 1-12-2013 by blargish]

subsecret - 14-12-2013 at 09:17

I dropped a 500 mL RBF on the concrete floor of my lab a while ago from about waist height. It bounced a few times, but luckily it was recovered without a chip. It shows no abnormal nucleation points during boiling (no lines of bubbles indicating invisible cracks). Not something I would expect from Bomex.

Pyro - 14-12-2013 at 11:28

lucky! I had something similar with a hollow 29/32 stopper.
It was greased and on the top of my Cl2 generator, the pressure built up and it shot out of the funnel and bounced waist height off the brick floor. It was intact but the lab smelt a little poolish after that

Cracked condenser

NexusDNA - 26-12-2013 at 15:14

I made the stupid mistake of discontinuing the cooling while there was still boiling in the distilling flask. Consequence: a crack in the first turn of my beloved 600mm graham condenser.

The worst part? It was distilling water. :mad:

Pyro - 26-12-2013 at 16:42

Ouch, take it to i know a good one... Werner Vitt in Bruges

Gooferking Science - 27-12-2013 at 09:39

Here is a series of stories. One day I was making nitric acid from potassium nitrate and sulfuric acid distillation. My mom came out to my lab to see what I was doing, and she accidentally undid my clamp, which made the boiling flask smash in my fume hood, distributing nitric acid on the table.

The next week I had ordered a new flask (A two neck) I distilled some ethanol in it, and the yeast burnt because I forgot it was distilling. The flask was ruined with carbon stains.

I ordered another two neck RB, and I accidentally dropped it when I had 500 ml of bleach in it, making a huge mess in my lab. I have not had an accident with an RB since, because I am much more careful.

Pyro - 27-12-2013 at 17:56

Gooferking, to get rid of that C mess put a bit of chromic acid in the flask (how much depends on how much mess there is) then gently heat the flask on a yellow sooty bunsen flame until the acid starts to fume. the stain should be gone after that. I did this just today with some black organic gunk that nothing would remove.

Today I removed some organic crap from my 1l sep. funnel with MeOH, then I drained and stoppered it and put it in the washing up sink, forgetting that it was full of hot water. after a few mins the stopper suddenly shot out and smashed into the wall, nearly hittIng my face!

HeYBrO - 27-12-2013 at 19:37

I was cleaning up after an experiment and i dropped my thermometer into my 100 ml measuring cylinder from about 3 inches and it smashed the bulb ( lucky it wasn't mercury ). One time after purifying sodium carbonate in a 400 ml beaker i dried it on my hotplate which caked really badly onto the beaker. I got spatula to chip it away and i poked the spatula right through the beaker... luckily all my mishaps were relatively cheap.

Lambda-Eyde - 27-12-2013 at 23:22

Quote: Originally posted by NexusDNA

I made the stupid mistake of discontinuing the cooling while there was still boiling in the distilling flask. Consequence: a crack in the first turn of my beloved 600mm graham condenser.

The worst part? It was distilling water. :mad:

This doesn't make any sense at all. A condenser shouldn't crack from boiling water without cooling, the temperature difference is only 70-80 degrees, which is nothing. It should handle at least 200 degrees without cooling. When using cooling water the distillate shouldn't be coming over at a temperature exceeding 150 C or so, the thermal shock might crack it. But boiling water, without cooling? Be very glad you weren't distilling nitric acid and that the condenser broke without turning into a disaster. Claim your money back, never buy from them again, and buy a liebig from a reputed manufacturer.

HeYBrO - 29-12-2013 at 16:50

Quote: Originally posted by Pyro

put a bit of chromic acid

there are better ways of cleaning glass than chromic acid. that stuff is horrible for you and the environment! plus there are better ways of cleaning carbon gunk see Cleaning of various "materials"

[Edited on 30-12-2013 by HeYBrO]

[Edited on 30-12-2013 by HeYBrO]

blargish - 30-12-2013 at 08:18

Quote: Originally posted by Gooferking Science

The next week I had ordered a new flask (A two neck) I distilled some ethanol in it, and the yeast burnt because I forgot it was distilling. The flask was ruined with carbon stains.

I came across a really effective way on Youtube of getting rid of organic residues and carbon stains. Place the flask/beaker/whatever inside of a larger beaker to collect foam (the cleaning reaction foams over very violently). Add concentrated (~35%) hydrogen peroxide to the flask and follow it up with the addition of Iron (II) chloride solution. After the reaction, most of the residue, if not all, should be gone. Repeat if necessary. This has worked well for me in the past.

DJF90 - 30-12-2013 at 09:12

@Blargish - This is Fenton's reagent and relies on the formation of Fe4+ and OH radicals, both actively oxidising species. Even dilute peroxide should work well.

Mailinmypocket - 9-1-2014 at 08:27

A few minutes ago I smashed a bottle containing a little under 2.5 litres of pentane on the floor... Thanks to my ID card which is on a lanyard around my neck getting snagged on the handle of the bottle on a shelf when I was unpacking an order Now I'm going to complain about how we need clips instead of the standard issue lanyards. Thank god it wasn't something more dangerous than being very flammable.

DJF90 - 9-1-2014 at 13:39

My access card is on a lanyard also but I just tuck it in my shirt pocket.

*FWOOSH* - 12-1-2014 at 12:35

I just broke ANOTHER thermometer. That's three mercury thermometers and two spirit thermometers (one of which had a ground joint...) in the past three months. Also ran out of vacuum distillation adapters after I broke the barb off my last one.

[Edited on 12-1-2014 by *FWOOSH*]

zenosx - 15-1-2014 at 15:16

Smashed one of my last two Hg thermometers from stupidity with it just measuring a water bath. Arrgg. Used sulfur to clean up the bit of Hg I didn't recover...

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