Dissolving glass in hydrofluoric acid - GIF

Dissolving glass in hydrofluoric acid.

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Previously:

https://www.homemadetools.net/forum/...328#post188727
https://www.homemadetools.net/forum/...798#post156106
https://www.homemadetools.net/forum/...288#post150284
https://www.homemadetools.net/forum/...538#post170195
https://www.homemadetools.net/forum/...093#post187771

Cody's Lab did a great video on this. He was trying to prove that it was impossible to bore a hole through tempered glass because the internal stresses were too high. So he figured instead of mechanically drilling through the glass, if he used acid to slowly eat through the glass over the timescale of weeks he could eliminate a source of error from the experiment. Very interesting stuff. Spoiler: the glass shattered.

https://www.youtube.com/watch?v=C_c_DP3khtw

HF is seriously dangerous. Intel uses it in their chip making process, so there is piping carrying HF inside their fab buildings. We are warned that HF is odorless and doesn't burn like an acid if it gets on your skin. However, it will work it's way thru your skin and attack the calcium in your bones. Apparently, it's a painful process. If a liquid drips on you, you are supposed to immediately get in a safety shower for 15 minutes unless the liquid is determined to be water before time's up. Oh, and the safety shower water isn't heated. It's room temperature, at first, then it gets really cold.

We each had tubes of Calcium Gluconate antidote gel issued in the past, now it's kept near to the use point, but the whole reason it was issued is you may not realise until you get home you've had a drop on you, though we now have this as well https://www.diphex.com/hexafluorine/...ne-information and it works better than CG.
We have a HF pump process for cleaning glass wear, no-one is allowed near it when it's running. One line operative at Mullards didn't take her rings off as she was running late one morning, the stones on her engagement ring wore through her gloves allowing HF in, only when the bone pain started did she remove the gloves, her ring finger came off with them... A 1% of body area HF burn is enough to kill, often through systemic toxic effects causing a heart attack which requires IV antidotes to prevent, accidental ingestion is not uncommon in poorly managed labs as HF looks like water and depending on dilution no warning odour may not be present.

Traditional Pub windows were made using wax negatived glass sheets dipped by hand into tanks of HF, now they use LP abrasive methods...

Stainless steel pickling gel for cleaning up welding discolouration and removing corrosion promoting oxides (some cleaning solutions for motorcycle exhausts as well) are HF based and commonly available!

(Edited for clarity).

Quote:

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Originally Posted by NeiljohnUK

Stainless steel pickling gel for cleaning up welding discolouration and removing corrosion promoting oxides (some cleaning solutions for motorcycle exhausts as well) are HF based and commonly available!

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I didn't know that. Very interesting.

I worked in a mineralogy lab where we were changing out fume hoods. They would boil mineral sample in little teflon yogurt containers on a large hotplate. We had a lady watching us all the time we were in there being sure that if we get any of the HF on us to notify her immediately. Needless to say we were slightly careful not to bump anything that was capable of dissolving rocks! But I did smell the acid vapours. I guess in low concentrations, or in reaction with some of the minerals. It was an interesting job. We took out a 50 plus year old fume hood made from Birch plywood and installed a sheetmetal one that my guess in that lab would not last more than a few years.

Quote:

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Originally Posted by mwmkravchenko

We took out a 50 plus year old fume hood made from Birch plywood and installed a sheetmetal one that my guess in that lab would not last more than a few years.

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At one of our satellite sites operated by our National Oceanographic outfit they installed a full suite of Stainless Steel fume cupboards in their new building, 6 months in they were ripping them and the extract ducting out to replace it with fibreglass fume cupboards and plastic (Teflon) lined extract ducts, HF and other acid mixtures had turned them red and holey...

-Ah yes - isn't just Fluorine absolutely divine to work with?

Check this post with attached video as to what PPE to use and avoid when handling ClF3:

https://www.homemadetools.net/forum/...110#post145425

In a former job I was working in a facility that used CNC machines to etch quartz with an HF solution. The parts were in a special PVC tray that was fixtures on a stainless steel base. The stainless steel base wouldn’t align properly so I pulled it out and it looked like it had been made from a sintered stainless. Over many years the acid had dissolved part of the SS and made it porous (but it was still very flat). I replaced the SS with PVC and it held up for the remainder of my involvement with the machines.