Cleaning glassware

[Martijn]

I would like to know how do members clean their glassware?

Sometimes I wash beakers and flasks in dishwater, but most of the time I just wipe it off with a damp toiletpaper and spray the inside clean. Most digestions I do are dirty, so I use the beaker that had hot AR in it for the precipitation with SMB.
This way the gold does not stick to chemical stains on the glass.
And you have an AR-cleaned beaker or flask.

Another thing I wonder is can dish soaps and such cause harmfull fumes in the dish water even after rinsing?

The use of Bon Ami is common here amongst members. The info I can find says its a combination of soda ash, baking soda, calcium carbonate and feldspar powder. And a surfactant.
Is this better than regular dish soap?

Is pre-rinsing enough to avoid fume problems?

Can the dishwater go down the drain(as I do) or does it need some treatment?

Interesting things to have discussed in one thread. ?

Martijn.

 

[4metals]

I always rinsed glassware well and used a commercial dishwasher with alconox detergent. I never let dirty glassware dry out, that makes it worse. And for really bad stains and stubborn crust I used this.

 

[haveagojoe]

never let dirty glassware dry out

Definitely. I have just spent over an hour scrubbing out some secondhand glassware- I've no idea what was on them but even wire wool wouldn't touch it, I was starting to think something had etched into the glass. In the end I resorted to a razorblade which got rid of it eventually! 2 beakers done, 6 more to go with the same crusty ring... I think they can wait for another day.

 

[4metals]

I was spoiled with a dishwasher in the lab but the Alconox detergent works well to just soak glassware in. I know a good number of refiners who have a cut down drum full of water with alconox detergent dissolved in it. They simply rinse their glassware first and let it soak in the soapy tank for some time. It is still very effective.

Nothing is as nice as having your precipitated gold slide smoothly out of a beaker. Or conversely, nothing is as frustrating as having your precipitated gold stick to the walls of your "not so clean" beaker.

 

[haveagojoe]

Alconox detergent

It seems to be rather expensive stuff... perhaps whoever had these beakers before me decided it was cheaper to buy a new one each time

 

[4metals]

The chromerge I posted a link for above is a very aggressive cleaner of glass. It is made by dumping one of the bottles of chromium trioxide into a bottle of concentrated sulfuric acid. It is used concentrated and can be re-used quite a few times until it turns green. Not exactly friendly to waste treatment either.

 

[haveagojoe]

very aggressive

Yes I was reluctant to use any kind of acid on them since I don't know what was on there, it could have been anything, so I opted for good old elbow grease. When I got them visibly pretty clean I put some old dilute Copper Chloride solution in them to soak which I'm hoping will gently remove any remaining traces.

 

[Shark]

Some of the nastiest beakers I have had came from a cosmetic school where they taught makeup design. I never did get a couple of them clean enough to feel comfortable using them.

 

[Thomas M Joseph]

In the old days we used a warm solution of potassium permanganate to soak, followed by a soak in dilute HCl to remove any permanganate stains, rinsed in distilled water to remove the acid. Came out very clean.

 

[Elemental]

I used to use acid/base baths to ultraclean glassware for analytical research (polar strength of mixed organic solvents - for super-critical carbon dioxide separations). Works great for organic stuff. Probably not as applicable for refining, but if you get your hands on some used glassware it may be worth looking at for that initial cleaning. Just need some potassium hydroxide pellets and isopropyl alcohol for the base bath.

NileRed Video on Acid/Base Baths:
Harvard Lab Safety Guide for Acid/Base Baths: https://www.ehs.harvard.edu/sites/default/files/lab_safety_guideline_base_bath.pdf