Properly cleaning lab glassware - is it possible?

Jeff Bannow · Jan 23, 2011

I have a large collection of lab glassware that I was given, all used in a high school lab. It is physically in great condition and should work wonderfully in my darkroom.

My concern is getting the glass chemically clean. I don't have access to an autoclave, so what are my options? Any chemical cleaners that work well enough?

Is it a real concern - can I contaminate my chemistry through trace amounts of things that won't wash out?

I plan to use some of this glassware for wet plate work, and don't want to ruin expensive chemicals due to contamination. I also don't want to junk this stuff and buy new if I can avoid it.

Photo Engineer · Jan 23, 2011

Jeff;

If I tell you the secrets of absolute glassware cleaning, it will be "out there". And, no one will be willing to use it!.

Method 1. Make a saturated solution of Potassium Dichromate in concentrated Sulfuric Acid. Soak your glassware in this for a few days and then rinse with copious running water.

Method 2. Add Potassium Hydroxide to iso-Propyl Alcohol until there is solid KOH left over. This is a saturated solution of Potassium Iso-Proponalate, IPA and KOH. Soak your glassware in that for a few days and then rinse with copious amounts of running water.

Barring that, use soap, hot water and elbow grease!

PE

131802 · Jan 23, 2011

A loooooong time ago I worked in a lab where we cleaned our glassware in sulfuric acid, followed by a distilled water rinse. Probably not a great idea for a home darkroom.

Hops · Jan 23, 2011

How about Hydrochloric acid? Cheap at the hardware store, sold as muriatic acid.

Jeff Bannow · Jan 23, 2011

Lots of scary chemicals! Sounds like fun.

So, soaking in strong acid should take care of it, without eating through the glass and consuming my whole house?

Photo Engineer · Jan 23, 2011

Hops said:
How about Hydrochloric acid? Cheap at the hardware store, sold as muriatic acid.

Did I mention HCl? No, I did not.

It is not used due to the extreme odor.

PE

Jeff Bannow · Jan 23, 2011

Photo Engineer said:
Jeff;

If I tell you the secrets of absolute glassware cleaning, it will be "out there". And, no one will be willing to use it!.

Method 1. Make a saturated solution of Potassium Dichromate in concentrated Sulfuric Acid. Soak your glassware in this for a few days and then rinse with copious running water.

Method 2. Add Potassium Hydroxide to iso-Propyl Alcohol until there is solid KOH left over. This is a saturated solution of Potassium Iso-Proponalate, IPA and KOH. Soak your glassware in that for a few days and then rinse with copious amounts of running water.

Barring that, use soap, hot water and elbow grease!

PE

How did I know you would have an answer?

I take it Method 3 is my best bet then? Are the other 2 reasonable for a home darkroom user?

Photo Engineer · Jan 23, 2011

I use methods 1 and 2. I use method 1 for my 4x5 glass plates!

But then I am a chemist.

I tend to do things many others are not trained to do.

PE

Jeff Bannow · Jan 23, 2011

Photo Engineer said:
I use methods 1 and 2. I use method 1 for my 4x5 glass plates!

But then I am a chemist.

I tend to do things many others are not trained to do.

PE

Indeed, I'm no chemist, though I am smart, meticulous and can follow directions. Are there dangers in this method? I assume that skin contact and breathing the vapors would be bad news?

Photo Engineer · Jan 23, 2011

I use rubber gloves and a lab coat along with old clothes. I use safety glasses with shields and I work slowly with no rushing around. I use every precaution I can in my lab and have a neutralizing solution there (Carbonate) in case of an acid spill.

PE

winger · Jan 23, 2011

#1 can remove fingerprints - don't ask how I know. They do come back.
At the lab, we tended to use the same bottle for the same thing so didn't put a huge effort into cleaning them. We scrubbed with a commercial glassware cleaner then rinsed with alcohol.

An autoclave just melts stuff that can't take the temp and kills organisms. It wouldn't get rid of chemical leftovers.

Barry S · Jan 23, 2011

Jeff-- There's no need to get crazy here. The rigorous cleaning methods outlined above aren't necessary for general photographic purposes. Even in my career as a research scientist--there were only certain circumstances that required intensive glassware cleaning. I suggest a mild residue-free detergent like LIQUI-NOX. These kinds of detergents generally do a great job for most uses. I (and most wet plate practitioners) use a motley assortment of glassware for wet plate with no ill consequences. If you have any glassware with visible mineral deposits, you could do a mild acid wash before the detergent rinse.

john_s · Jan 23, 2011

We used to use a product called Decon 90. It was extremely alkaline. It cleaned well, but there are probably residues that it would not work on. For example, a deposit of calcium compounds can be better removed with acid.

2F/2F · Jan 23, 2011

Photo Engineer said:
Did I mention HCl? No, I did not.

It is not used due to the extreme odor.

PE

No, you did not mention it. But will it work? When I did construction, I used that stuff outdoors all the time to etch concrete, and the odor was certainly manageable if handled properly. If the chemical will do the trick, perhaps soaking the glassware in a covered container outside would work for Jeff.

Ross Chambers · Jan 24, 2011

Must not be flippant, must not be flippant...

Why do I think of "Breaking Bad" when I read this thread? I'm sloppy, hot water and detergent, but that's from ignorance, not knowledge and experience. Interesting information.

jfdupuis · Jan 24, 2011

I would say that the appropriate method is to identify what you have to clean and then use the appropriate solvent. Diluted sulfuric acid works great for me in the darkroom for the annual cleaning.

Photo Engineer · Jan 24, 2011

HCl will work, but since it is about 0F here right now, it does tend to escape my mind due to the need for outdoors work.

It is also not commonly used in labs for cleaning. The potency changes with time.

The cleaning methods I mentioned are designed to remove encrusted residues of all types and to oxidize (with dichromate) anything that might be there that might be "harmful". I use the dichromate/sulfuric acid method as one step in cleaning glass plates.

PE

Rick A · Jan 24, 2011

I used to use "Polident to clean my slot processor between batches of chems. It may take a couple of doses, but if you follow the package instructions, it works well. And, NO, I dont have false teeth, my BFF used to clean his labware with the stuff, and it would sparkle. Oh, and it smells minty fresh.

jeffreyg · Jan 24, 2011

I suggest using eye protection when handling the above mentioned chemicals.

http://www.jeffreyglasser.com/

Photo Engineer · Jan 24, 2011

Gloves, eye protection, lab smock and old clothes and shoes!

PE

Jeff Bannow · Jan 24, 2011

Photo Engineer said:
Method 1. Make a saturated solution of Potassium Dichromate in concentrated Sulfuric Acid. Soak your glassware in this for a few days and then rinse with copious running water.

How much of each? I assume I can reuse this solution (pour it from one container to another?)

Photo Engineer · Jan 24, 2011

It can be reused.

I use battery acid, which is about 35% H2SO4. I use enough Dichromate to make a saturated solution with some Dichromate on the bottom. Then I use the liquid and as I use up the liquid, I pour in more acid gradually using up the solid in the bottom, so I keep my original mix fresh and "going" and re use the used material stored in another bottle. When it appears grungy, I pour it out or better still, add some fresh thereby replenishing it.

PE

mwdake · Jan 24, 2011

and shoes!

That rules me out.

dwross · Jan 24, 2011

Barry S said:
Jeff-- There's no need to get crazy here. The rigorous cleaning methods outlined above aren't necessary for general photographic purposes. Even in my career as a research scientist--there were only certain circumstances that required intensive glassware cleaning. I suggest a mild residue-free detergent like LIQUI-NOX. These kinds of detergents generally do a great job for most uses. I (and most wet plate practitioners) use a motley assortment of glassware for wet plate with no ill consequences. If you have any glassware with visible mineral deposits, you could do a mild acid wash before the detergent rinse.

Listen to this man! . No need for craziness, indeed. For the very dirtiest of labware: Hot water and dish detergent, followed by a thorough scrub with 'Bar Keepers Friend' (contains oxalic acid), followed by a good rinse with hot tap water. Sometimes I'll follow with a last rinse in distilled water with a splash of Everclear, but then I just feel foolish about the overkill!

d

Photo Engineer · Jan 24, 2011

As asked in the OP "can I contaminate my chemistry through trace amounts of things that won't wash out?" and the answer is "YES" and I have given the best remedies for this. It will clean out all unknowns.

Under normal conditions in my lab, I KNOW what is there and based on that I use detergent, a rough sponge and hot water. This is a different situation than described in the quote from the OP.

And, there are all levels in between.

PE

Properly cleaning lab glassware - is it possible?

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