Sciencemadness Discussion Board

How do I make permanent glassware markings?

FrankMartin - 28-10-2011 at 15:16

I mean on glass apparatus not normally calibrated. Do I rub the glass with fine emery paper and then write on the roughened surface with a graphite pencil? Would this weaken the glass? Is there some sort of etching fluid available?

Also I want to make marks on a distilling flask to tell how much liquid has boiled away. And I want a permanent tare weight marked on all glassware.

Magpie - 28-10-2011 at 15:32

A glass etching product (contains ammonium hydrogen fluoride IIRC) is available at craft stores. I don't see where a superficial etching would significantly weaken the glass - that's likely the way the pro's do it.

bahamuth - 28-10-2011 at 16:41

A very neat rick on ground glassware is to write with a pencil on the ground part of the glassware, on inside joints if possible, sticks forever

Endimion17 - 28-10-2011 at 16:52

Quote: Originally posted by Magpie  
A glass etching product (contains ammonium hydrogen fluoride IIRC) is available at craft stores. I don't see where a superficial etching would significantly weaken the glass - that's likely the way the pro's do it.


He asked about the emery board scratching. That would weaken the glass. Etching fluids are fine, of course.

DJF90 - 29-10-2011 at 01:54

I can attest graphite use on glass joints lasts forever, as some fool did that in the lab I'm working in and I find it incredibly annoying. I havent however tried very hard to remove it, but I suspect treatment with chromic acid or piranha solution would be effective. It is possible to purchase a glass writing diamond /diamond pen which details to be scratched into the glass - older pieces of quickfit have their model number marked in this way.

Just a note to consider: permanent marking of a tare weight is pointless, as it will never be the same. You should tare glassware as you use it, because you can only tell its exact mass as and when you use it. Variations in mass are observed typically due to moisture residues or silylation of glassware, or loss of material due to treatment with a base bath.

watson.fawkes - 29-10-2011 at 07:22

Quote: Originally posted by FrankMartin  
I mean on glass apparatus not normally calibrated.
If you have access to a kiln with a good temperature controller, you can use ceramic decals and fire them on to your ware. Bonus annealing cycle!

fledarmus - 29-10-2011 at 13:00

Just use a sharpie. Writes just fine on smooth glass, wipes off with acetone or alcohol.

Endimion17 - 30-10-2011 at 01:14

Quote: Originally posted by DJF90  
I can attest graphite use on glass joints lasts forever, as some fool did that in the lab I'm working in and I find it incredibly annoying.


Ditto. :D

unionised - 30-10-2011 at 01:49

"How do I make permanentglassware markings?"

"Just use a sharpie. Writes just fine on smooth glass, wipes off with acetone or alcohol."

Dr.Bob - 3-11-2011 at 08:45

If you buy the Sharpie industrial markers that say "Super Permanent Ink" in red and black text, they will resist nearly every solvent except DCM. We use them all of the time in the lab and they will last for a long time, unless you wipe them with DCM and scrub them. There are also silver and white markers that leave an almost enamel like writing which work well.

If the glass has a white patch, then pencil will last a long time as well. If there is no patch, Sharpie is best. Scratching with a diamond or etching the glass will cause some weakening, plus it is silly to "permenently" mark a tare weight, as DFJ90 said, the tare weight will change as you chip a joint, clean in a base bath or get some residue on the flask. Plus some balances drift, so taring the flask immediately before use is best. That is why we use the industrial sharpies, they last a few uses and then you can wipe it off with DCM if you want to retare it. I have vials that are over 10 years old marked with a Sharpie and they are still legible. Many paper/plastic labels fall of far before then.

The best solution I have seen is to laser etch on the white spot on glass. We got vials and tubes with white patches and had a company use a small laser cutting device set properly and they could barcode the vials with an etched black on white which read perfectly forever, did not wash off under any conditions, and did not change the weight of the vial like a paper label does. (not only when you put it on, but the paper label absorbs enough humidity to change the weight by +- 0.5 mg depending on the weather.)

That was the best label system I have ever seen. For info, see http://www.twdtradewinds.com, they are a great company to work with.

Bob

[Edited on 3-11-2011 by Dr.Bob]

BromicAcid - 3-11-2011 at 14:05

In our lab we routinely use a paint pen which cleans off easily with acetone. IF however we use that paint pen on a flask and heat that flask to, oh... 300°C or so, it no longer comes off the glassware :D Never did this intentionally however.

Endimion17 - 3-11-2011 at 14:38

Quote: Originally posted by BromicAcid  
In our lab we routinely use a paint pen which cleans off easily with acetone. IF however we use that paint pen on a flask and heat that flask to, oh... 300°C or so, it no longer comes off the glassware :D Never did this intentionally however.


... unless you use acid piranha. :)

semiconductive - 30-1-2018 at 20:23

Quote: Originally posted by Dr.Bob  
If you buy the Sharpie industrial markers that say "Super Permanent Ink" in red and black text, they will resist nearly every solvent except DCM. We use them all of the time in the lab and they will last for a long time, unless you wipe them with DCM and scrub them. There are also silver and white markers that leave an almost enamel like writing which work well.


Perhaps times have changed ... this is so frustrating.
I went to the construction supplies store and shopped online, bought every sharpie ... super fine point, super this super that... almost every stinking pen and re-brand was advertizied with disclaimer they no longer use "xylene"; All markers came off with isopropyl alcohol except the one called "Sharpie pro industrial super permanent markers"; The label on the side of the pen is in red instead of black, otherwise the pen looks like a normal sharpie.

That one seemed to work, until I tried an experiment that needed methanol and I used denatured alchohol hot as a substitute ... the tare weight faded off the glass even when the alcohol was cold. Hot denatured alcohol could take it all the way off... since I'm boiling crystalline solutions and using alcohol to precipitate, it's inevitable that it would hit the ink.

This is a good marker, resists acetone, etc. But on very smooth glass, hot denatured alcohol appears to make newer (2018) pens come off :(

I did a search online, and someone else noted a similar clean wash off problem when marking several materials except metal.
https://artsupplycritic.com/2016/02/22/review-sharpie-indust...

[Edited on 31-1-2018 by semiconductive]

semiconductive - 30-1-2018 at 20:37

Quote: Originally posted by BromicAcid  
In our lab we routinely use a paint pen which cleans off easily with acetone. IF however we use that paint pen on a flask and heat that flask to, oh... 300°C or so, it no longer comes off the glassware :D Never did this intentionally however.


I bought milwaukee brand inkzall, and paint pens (jobsite markers and paint pens).
The inkzall just washed off with alcohol, and I hit it with a butane torch until glass started showing slight red... but those still washed off.

Then I marked it with the paint pen (white color), and hit it with a torch after waiting ten seconds. All of the white was turned to a bright yellow, except the last number of the tare which hadn't quite dried before being torched and became brownish. After cooling, the yellow turned back to white; so the pigment is probably zinc oxide in some kind of hydrocarbon binder that burns and reduces some of the ZnO.

It still ran on the glass when hit with IPA. Some of the residue still stuck to the glass, but it was smeared the point of being unreadable. The only part which didn't run down the glass was the burnt digit that wasn't dry when torched; That at least took the alcohol without disfiguing; but once wet with alcohol, touching it caused it to flake and smear immediately.

I'd love to know which brand of pen you originally used to get that permanent result. I'm not sure if there's a way to chemically treat the ZN-O pigment to make it more permanent....

The vials I am using are mostly disposable at 50cents each, so that if the tare weight is significantly off ... I'll just throw it away. But I've never seen a tare weight change by even 1 milligram in the experiments I've been doing. Besides which, I've figured out that I can add weight to an existing glass by putting water-glass and borax on it and hitting it with a torch, followed by sulfuric acid, and a second brief torching. The only kind of weight change that doesn't require throwing the glass out due to a contaminant, is a weight loss. So, the only compensation that is needed should be to add extra borosilicate to restore a tare in case of chipping or etching. It's actually pretty easy.

semiconductive - 30-1-2018 at 21:05

As an additional question, on the OP.
Has anyone tried the "Azer-Ink" chemically resistant pens? I'd buy it and try it, but they only sell them by the dozen ... and $53.30 is the cheapest price I've found. That's a bit steep for a pen that I've no review on it good/bad points.

https://www.thomassci.com/Laboratory-Supplies/Pens-and-Penci...

RogueRose - 31-1-2018 at 01:11

marking off with masking tape and then light sand/bead blasting? or maybe there is a caustic or acidic paste that could be spread on to dissolve the glass but not effect the taped areas.

hyfalcon - 31-1-2018 at 05:53

Quote: Originally posted by RogueRose  
marking off with masking tape and then light sand/bead blasting? or maybe there is a caustic or acidic paste that could be spread on to dissolve the glass but not effect the taped areas.


Ammonium Fluoride or ammonium bi-fluoride will act as an etch-ant.

Sulaiman - 31-1-2018 at 08:15

I am changing from marking tare weights on vessels to just putting an identification mark and keeping track of tare weights in the back of my lab notebook, easy.
(my scales resolution is 10mg and accuracy about +/- 20 mg so tare weights do not noticeably change - if clean and dry.)

Due to the varied nature of my glassware collection (different brands and ages) often no marks are required.