How It's Made Opalescent Glass (and more Kokomo)

I visited Kokomo Opalescent Glass a few years back, driving to Indianapolis and a half hour north, and paying my five dollars (it's now up to six dollars per person) to take the tour.

I'm pretty darn sure that the above video is from Kokomo's factory, because the videos that Kokomo posted look identical to the one above.






If ever you want to thank your friendly, neighborhood blogger for all the work that he does, might I recommend either a cast or a water jet cut, red Indiana?

Kokomo Opalescent Glass factory tour - 3-26-14

It's spring break, and what better way is there to celebrate than by taking a trip three hours northwest to Kokomo, Indiana to tour the Kokomo Opalescent Glass (KOG) factory?

We (Becky and Lonnie) had seen the videos of glass being poured at KOG and even shown them in the summer camps - including at the University of Indianapolis on the south side of Indy, but we had never made the trek to the far north side to see KOG, a world-famous maker of art glass.

The trip is about three hours each way from Cincinnati, but it's an easy enough three hours with the factory being about forty-five minutes north of the loop interstate around Indy but forty-five minutes on a four-lane highway most of the way.

The factory tour only runs once a day - at 10am, so we set off early and arrived at 9:30 as the tour was actually about to get underway. They had a pre-arranged tour of local school children coming in at 10am and wanted to get the day's open tour of a dozen adults moving before the school children came through.

The tour guide (David, far right, first row under The OP Shop Team) was highly knowledgeable, having working at KOG for three years but having worked with glass for more than thirty years. David took us through the hot shop with its twelve kilns (each replaced once every four months or so, the entire kiln shut down and rebuilt once every twenty-five years, glass heated to 2600 degrees [Fahrenheit, David thought]). We got to see the workers pour a few smaller sheets using the catspaw rollers, producing a gorgeous and heavy texture on one side of the 1/8"-thick glass sheets. The sheets were pushed into an annealing, conveyor-belt over for a forty-minute cool time (far shorter than either of us expected). We didn't take long enough to see 'our' sheets come out the other end, sadly.

The next stop was to the glass blowing room where we saw two blown rondels being made and saw the finished products of the glass blowing shop including some gorgeous paperweights. Never knew that the bubbles in the paperweights (like this) were created by rolling the hot glass in baking soda (2 NaHCO₃ --> Na₂O_(s) + 2 CO_2(g) + H₂O_(l)).

We headed to see the large, glass sheets trimmed with impressive efficiency. Sadly 'our' sheets that we'd seen poured weren't quite out of the annealing process for us to see. We did get to see into the 'rainbow room' where many of the glass sheets are stored. We watched some glass beads be made and wrapped up our tour back in the OP shop.

Check out our pics and vids...

Broken glass gets collected by color to be reused.

Bullseye Factory Tour

You might've seen the factory tour videos of Kokomo Opalescent Glass that I've posted before

If so, you might also have seen my comments that the lack of PPE used when the glass ingredients are being measured out. I comment on that every year with my students because I make them wear N95 masks when they measure out the silica and other glass batching ingredients. They're doing it once, and I insist on PPE. The Kokomo folks are assumedly doing that every day and - at least as of the time of the videos being filmed - they aren't using any breathing protection at all.

Today's video works as a contrast to that with Kokomo representing an old-school, 'that's how we've always done things' look at manufacturing, and the Bullseye Factory Tour shown above shows how more modern manufacturing should look.

I went looking for more Bullseye factory tour videos to check for PPE again. The above one was posted in 2017, and it shows PPE. The below one was posted in 2016, and it shows PPE. There's another that's dated 1979 that doesn't show the same PPE, but it also doesn't show the ingredients being measured out, and that's where I'm most concerned about the use of PPE masks. It does, however, show smoking on the floor of the glass factory which feels incredibly dated. The second video below, the one from The Oregonian specificially mentions some of the environmental concerns involved in the production of glass. It's more about the use of heavy metals, but it's a valid concern.

KOG Rolling Glass for sheet glass

Kokomo Opalescent Glass in - shockingly - Kokomo, Indiana is one of the country's top art glass manufacturers, and happens to be only three hours from my house. Looks like I have a field trip to make since Caryn Jackson - another of our ASM master teachers - endorses the factory tour so heartily.

Here we get to see the workers/artisans/guys mixing glass from their beehive and rolling the glass into sheets which will then be sold in the factory's shop. Lucky for us the KOG company has posted twenty-two videos from their factory.

Mixing Sand Batches for making glass at KOG Glass Studios in Kokomo

We've begun doing some glass batching in our material science course at Princeton High School, so far doing it as a class activity not yet as an individual student activity.

In our experiments, we use a recipe of sand (silica or flint), sodium carbonate, boric acid, and a metal oxide. Our mix totals 139 grams, enough to half fill a Denver crucible. We don't want to overfill and overflow that crucible because then we're destroying our kiln's liner.

The recipe in the video above makes a little more glass than ours does but is generally the same ingredients: silica, soda (sodium dioxide), lime (calcium dioxide - we don't use this, admittedly), and metal oxides to provide color to the glass.

I'm a little surprised to see the measuring and shoveling being done without any dust masks. Silicosis is no joke.

Lambert Glass (part 2)

Just more mesmerizing glass videos from Lambert Glass today. (Check out more Lambert videos yesterday.)

Above they make rolled table glass, similarly to how they make glass in Kokomo, Indiana.

Below they make traditional rondels and crown bullions.