Sciencemadness Discussion Board

Cleaning glassware...

JohnBee - 28-5-2015 at 06:37

Anyone know what's best for cleaning glassware?

For the past year, I've been using a chlorine dioxide solution which seemed to work well enough in terms of sanitization. Though I'll soon be out as it this was left over from a previous project and I won't be ordering more NaClO2.

For what it's worth, I need something that can break down nickel deposits/residue from glassware.

Zombie - 28-5-2015 at 06:46

Here's Sigma's PDF on the subject.

I've run plumbing into my lab for a wash sink, and the logical next step is a dishwasher for basic duty, and following leads like Sigmas for the stubborn stuff.

https://www.sigmaaldrich.com/content/dam/sigma-aldrich/docs/...

[Edited on 5-28-2015 by Zombie]

JohnBee - 28-5-2015 at 06:50

Awesome thanks!
Any recommendation on a dishwasher?

We currently own a Samsung in our home, but it really sucks at washing glass - lol

The recommendation for Chromic Acid really has be thinking my ClO2 solution was better than I may have first thought. Guess I should look into getting more NaClO2 as this seems like a safer option. :/

[Edited on 28-5-2015 by JohnBee]

Metacelsus - 28-5-2015 at 06:53

Soap, water, and vigorous scrubbing (with a bottlebrush) works for most things.

For the really stubborn stuff, I have used chloric acid/chlorine dioxide (sodium chlorate dissolved in hydrochloric acid).

Acid (hydrochloric, sulfuric, etc.) should dissolve nickel.

greenlight - 28-5-2015 at 08:33

98% sulphuric is good for getting stubborn stains off.
I usually rinse my quick-fit glass pieces (adapters,stillheads, sep/addition funnels) with a wash bottle of acetone after scrubbing with soap/detergent water as it cleans any stains left over and gets rid of any grease from the joints which takes ages to wash off with normal soap-water.
I highly recommend the dishwasher as long as the glass is pre-rinsed and cleaned of chemical residue and nothing on them is toxic...I sometimes rinse my beakers with detergent water well and place them in the Bosch dishwasher I have on the half hour cycle. They come out looking like they are brand new:D
Wouldn't use that method if working with anything dangerous or poisonous though.

[Edited on 28-5-2015 by greenlight]

[Edited on 28-5-2015 by greenlight]

DraconicAcid - 28-5-2015 at 08:46

Depends on what is staining it.

The most stubborn stains I get are carbon deposits from the screaming gummi bear reaction. A bit of nitric acid heated with a Bunsen burner usually takes care of that.

Sulaiman - 28-5-2015 at 09:09

I have a slightly unusual situation,
almost all of my glassware I bought 'used' (cheap)
the more I use my glassware the cleaner it gets !

JohnBee - 28-5-2015 at 09:18

Quote: Originally posted by Sulaiman  
I have a slightly unusual situation,
almost all of my glassware I bought 'used' (cheap)
the more I use my glassware the cleaner it gets !

Some of the reissue on lab glass can be very stubborn to get off. Is it possible it's slowly eroding with use?

quantumcorespacealchemyst - 2-6-2015 at 23:03

sometimes i soak flasks in BORAX for a while (days, weeks) when they have stuck on stuff and i don't want to waste acids and stuff.

Zombie - 2-6-2015 at 23:20

I just figured whatever cheap dishwasher WalMart sells or Home depot... I like the idea it dries everything, and I don't have to sort anything right away.

Just something cheap, and small like an apartment size rig.

Tdep - 3-6-2015 at 00:40

Quote: Originally posted by quantumcorespacealchemyst  
sometimes i soak flasks in BORAX for a while (days, weeks) when they have stuck on stuff and i don't want to waste acids and stuff.


Hey QCSA you're still here! Good to see man, it's always a bit too easy to think the worst for you when you stop posting for a little bit.

/tries to replace thread back onto track

macckone - 3-6-2015 at 19:32

Let's not forget some of the less drastic solvents. Depending on the reaction, isopropyl alcohol, acetone, petroleum distillates, even Colman fuel, toluene. Vinegar is also sometime useful. We really should have a write up stickied because this comes up so often. Insoluble chloride and sulfates can sometimes be loosened up with nitric acid. Last resort solutions are piranha and chromic acid. Some insoluble sulfates are minimally soluble in concentrated sulfuric acid, like lead sulfate.

Dan Vizine - 3-6-2015 at 20:14

My favorite is the lab standard, alcoholic NaOH solution. Actually, KOH is usually used in lab baths, but Red Devil lye is much easier to get and cheaper. I use Home Depot's denatured alcohol, 1 gallon, about 50 - 100 ml H2O and granular NaOH to the saturation point. It also nicely removes silicone greases.

For fritted glass, I use conc. H2SO4 and once it's on the frit, I squit in alcohol with swirling to the boiling point. The base bath weakens frits.

[Edited on 4-6-2015 by Dan Vizine]