Is lab glassware still made by glassblowers?

I have an older colleague who knows a glassblower. We send our chipped and cracked glassware out to him and he fixes them and sends them back looking like new.

Ive been told as long as it isnt a star crack he can fix it. How is he repairing these? With some flux agent?

After talking to this coworker some more he claimed that most volumetric glassware (pipets, flasks, U-tubes) are still made by glassblowers the old fashioned way of using molds equivalent to the volume of water to reach the proper diameter/shape.

Is this true because some of the tolerances are pretty remarkable? This seems like a perfect task for a pneumatic robot.

It’s not quite what you asked, but when I was in grad school an awful lot of lab glassware – especially custom pieces – were handmade by glassblowers.

I can’t believe that the vast majority of glassware is hand-blown. All those Erlenmeyer Flasks and Florence Flasks and the like are too numerous and their production could easily be automated.

As far as volumetric flasks go, the reason there’s that long tubular section is because you account for variations in the manufacturing by using the position of the scribed line to show the volume – and there’s no reason the flask can’t be machine-made, then calibrated. I would be more inclined to make a machine-made pipette than one made by hand, myself.

In high school, we visited the school of science at a local university. One of the people who gave a presentation was a glassblower for the chemistry department. He made novelties like glass flowers for us, but my understanding was that his full-time job was building those complex assemblies used in experiments. I think a lot of this stuff is really custom, so it’s not possible to automate the production.

A lot of things are made by machine. Test tubes, pipettes, flasks, beakers, etc. are usually made by machine these days.

This video shows how they make test tubes and pipettes, for example.

There are a lot of things that machines don’t do a very good job with though, and for those there are specialized scientific glass blowers who make them by hand.

Here are some things being made by hand:

You can see that they have machines to semi-automate some parts of it. The latter half of the video also shows test tubes and flasks of various shapes being machine-made.

Thanks for the video
engineer_comp_geek “how its made” is a great show, its a shame comcast removed the science channel from the base package. Cant believe those workers aren’t wearing puncture resistant gloves though! I had a pipet tip stuck in the tip of my finger for over a year, it was a N2 sparge gone bad…

CalMeacham I suppose your right regarding the scribe line. I know they have different class pipets (a,b,c) if i recall and now I assume they just use a smaller I.D. Tube to get more precise measurements.

Anybody have any insight into glass repair? I can only think of some fluxing agent or re-annealing the glass to fill in the crack/void. It must be similar to a windscreen crack Ill have to read up on that later

A lot of glass making is done just like it has been done for thousands of years, but using better equipment. My wife and I went on a tour of Bullseye Glass here in Portland. It’s one of the premiere glass making companies in the world. In the bowels of the plant, it all boils down to a bunch of big, sweaty guys pulling melted material out of a blast furnace using big ladles, humping it over to another station where other big sweaty guys spread it out and run it through large rollers, either smooth or textured. It pops out the other side, cools a bit, then another large sweaty guy slides a giant spatula under it and humps it over to the annealing station.

My company buys glass from Schott (the company whose names are on the boxes in the video). I always have to suppress a chuckle when someone mentions “Scott glass”…:smiley:

Like the OP, all of our glassware repair is done by hand - a local guy who does a pretty good job. As far as what we purchase, I can’t believe it’s done by hand - we use a lot of three-neck flasks and condensers and they are all identical…OK, I don’t inspect each one with a microscope, but they are all interchangeable. I have to think ground glass joints are made by machine - in 35 years, I don’t ever remember seeing one not fit another (within the proper size)…

The chemist I worked for always salvaged the ground glass joints. Everything else can be re-attached, he always assured me. It’s basically plumbing.

Turns out they do just flame anneal the crack and then by pulsing air into the vessel work the crack out. Afterwards they condition it in an kiln to relieve any aquired stress.

Windscreen cracks are different and are simply filled with an epoxy resin.

I found an interesting post on the topic here by Zan Divine

Approach the star crack with a soft, medium warm oxy-fuel gas flame so as not to cause it to propagate. Move in circles around the star slowly closing in on it.

Increase the flame temperature until you have a well-defined inner cone about 1/2 to 3/4" long.

Focus on the star now. Heat it until the glass begins to sag inward about a mm or so. Don’t let the glass become too fluid to control. Easy does it. By gently puffing on a rubber tube connected to the flask joint, push the glass outward by a mm or two. The idea is to make the star look like a slowly pulsing lump. This works the glass and causes the crack to fuse. This cycle is done 10 or 12 times and then the shape is adjusted by final puffs as you cool the glass just enough so it stay put.

Slightly, and in gradual degrees, cut down on the oxygen while playing the flame in circles around the repair. Over 3-5 min gradually cut off the oxygen. Eventually, play the yellow gas flame over the area laying down a thick sooty layer. This is called flame annealing and, for small repairs not near strained areas, it is quite good.

Let it cool, wipe it off, good to go. You will almost always see a very very slight mark where the glass fused. Microbubbles. Not a real concern.”

In my final year studying physics we were expected to make any equipment we needed for our research projects. So they gave us a weeks course in using engineering equipment, including a couple of days in the glassblowing lab in the chemistry department. So I know how to make my own test tubes and how to weld two pieces of glass together without leaving a join. Skills that I have never needed in the 25 years since!

That glass blowing lab was mainly used for creating strange bespoke devices for chemistry and biology. Test tubes and beakers were commercially made by machines.

[quote=“Osano, post:10, topic:819292”]

Approach the star crack with a soft, medium warm oxy-fuel gas flame <snip>/QUOTE]

medium warm oxygen-fuel flame isn’t a phrase I am used to reading…
To me, all flames are hot to much much hotter!

One of my prize possessions is a small, delicate sculpture of two cranes, blown by the famed artist Mitsugi Ohno.

For many years he did specialty glass blowing for Kansas State University. He also did a wide variety of artistic pieces. When the Emperor of Japan visited the United States for the first time, the gift given to him by the government was a glass scupture of a famous Japanese castle, made by Ohno.

Read the article, and other stuff about him. My sister, who bought me the cranes as a gift, purchased one of his Klein bottles for herself. He was in Topeka unexpectedly and decided to deliver it to her in person, but she wasn’t home. Sis was devestated when she found out she’d missed a visit by this guy.