Calling all Etchers PCB & Enclosures: share your horror stories!

[Sensei Tim]

seeing as halloween is right around the corner, i thought it'd be good to share our etching horror stories..

picture this... you're relegated to doing kitchen sink chemistry. you just got your kitchen remodeled with a nice new white quartz counter top.  you make sure that you lay out towels and newspaper to cover the counter in case the ferric decides to splash. Everything is going well and you get your best etches EVER. you're pouring your ferric into the waste bottle (right?) when the funnel slips and you pour 1/2 a liter of used ferric chloride all over your brand new white counter top right as your wife walks in...

not enclosure related, but two other stories from when i was in school:

First one,  It was summer and the other grad student in my group was wearing open toed sandals in the lab. he splashed some concentrated nitric acid and a few drops landed on top of his toes.... he ran to the bathroom and i found him in there with his foot in the sink.

Second one, a new grad student didn't read the MSDS sheets and she decided it would be ok to etch silicon dioxide in hot hydrofluoric acid in a glass beaker on the counter in the middle of the lab without any PPE whatsoever.  Darwin will have a chat with her very soon, i think..

post yours....

[Chris60601]

LOL. Tim, its a wonder yer still alive to tell the tale of the countertops (assuming its your story that is) 😊

[Sensei Tim]

hah. not that's not a real story

my story is that i was etching in the bathroom and had the counter covered. i had finished and was pouring the spent etchant into a 2L pop bottle using a funnel. just as i finished pouring the funnel fell out and tumbled onto the floor and as it was spinning it was spraying small drops of ferric all over the mirror, wall, and tiles.

*heart attack*

 i think i managed to clean up everything with wet paper towels before it stained anything... and fortunately the tiles have some veins in them that have a similar colour to ferric ;)

[rocket88]

God damn, just reading the words HF gave me chills. That shit still just bothers the hell out of me after seeing it in it's special container, and containment in the chemical storage room when I was in collage.

No etching horror stories, but thought I'd just share an acid horror story. Back when I was in grad school and working in a chem lab my professor, who was amazing and now head of the chem department, had just explained the test we were going to run. We were supposed to make a dilute of sulfuric acid from a full strength concentrated stock bottle in order to run a titration on some samples to ensure they contained the amount of certain chemicals. Now, the professor and I used to joke around in the lab together. And I would always ask for clarification when diluting an acid if you added the water to the acid or acid to the water. For those that don't know you always add the acid to the water, as the deprotination is highly ectothermic the water essentially boils instantly and can shoot up out of the container. So anyways, this girl in the class added her sulfuric acid to her beaker, then fills another with the right amount of water for the dilution. She then adds the water to the beaker with the sulfuric. Now not only does the water shoot up at her from the opening in the beaker, but she didn't check her glassware first and it had a crack in it. Now what's worse then boiling sulfuric acid shooting at your face? Broken glassware flying as well. The beaker exploded and shot boiling sulfuric acid and shards of the beaker across the lab. The professor and I were across from her doing our usual bs, and we just stood there for a second in shock, and ran to help. Not only was she injured, but needless to say she was not allowed to work in the lab without someone directing her.

[Sensei Tim]

hah. we might have had the same grad student in the lab.  the one who was using the HF set fire to something in one of the fume hoods and the whole building was evacuated.

I always got the chills when i had to use HF. I'm so glad that I don't work in a wet chem lab anymore. piranha etch also always freaked me out when i had to use it to clean and prep samples.

The other stuff that gave me the willies were some of the gasses that we used in the CVD reactors.. phosphine, arsine, and silane.... any one on their own is bad enough, but all three in gas cyninders in blast proof cabinets that were backfilled with argon gas and... ugh...

[Silver Blues]

Yeah I'm in the middle of a chemistry degree myself, and thankfully no one has had a major accident in the time I've been there (I guess people around me are smart ) although my phys chem lab instructor was saying that an improperly sealed bomb calorimeter exploded in her lab one year... no one was near it when it happened but that's a scary thought. The thing is a massive steel cylinder under 20atm of pressure filled with pure oxygen.

[rocket88]

Mine said the same thing. Everyone in the class was freaking out when we used it because of the story.

[Silver Blues]

The question I have is what did they do wrong to cause it to explode?? The thing is solid as they come and I feel like if an explosion were to happen it would happen when charging it and not after it's been placed in the water bath and is running a reaction.

[rocket88]

Thermodynamics man, fucking thermodynamics. Lol

[Sensei Tim]

guys, in this forum we obey the laws of thermodynamics!

[rocket88]

rule one, you can't avoid entropy no matter how much you try, so just sit back and roll with it.