Corelle, melamine, or something else?

[Adelie]

You are correct, it is a tempered glass. But it is also more than that.

In tempered glass air is blown over both surfaces of a piece so the outer zones of the piece are cooler than the interior. Once the piece has solidified all the way thru the interior is still significantly warmer than the surface so it will shrink more coming to an even temp and the interior will be in tension and the surface in compression making it stronger than regular glass the same thickness.

The Corelle process uses 2 types of glass in 3 layers. The middle layer has a higher coefficient of thermal expansion/contraction. As a piece cools the middle layer tries to shrink even more than the outer layers do in normal tempering. Consequently there is more latent potential energy in Corelle as well as it being stronger than regular tempered glass.

[Gadagirl]

Bamboo? It also can't go into a microwave but it's nontoxic, unbreakable and comes in a variety of colors and paterns.

[BCCLover]

We've got regular old ceramic plates from Crate and Barrel, and real glass stemless wine glasses. Underway in general we use the bowls and not the plates; we have a couple of Tervis tumblers for general drinking (water) use. I really dislike the lightweight feel of Corelle and the plastic feeling of melamine. We do have grippy mats to use under them. In almost 30 years of on and off living aboard, some of that time with children, we have yet to lose a plate or a glass.

[JPA Cate]

We have some stoneware from Crate and Barrel, that was given to us 35 yrs ago or so. Some has broken (the handles on the mugs were fragile). I have 8 Corelle plates, but we use pottery bowls, and also have some plastic, that we use under way. After many years experimenting with the least expensive of stemware, I have shifted to using juice glasses, like the Basques, for wine. People don't knock them over waving their hands.

Just get what you prefer to eat off of; life's too short to use materials you don't like.

Ann

[Adelie]

Originally Posted by JPA Cate

We have some stoneware from Crate and Barrel, that was given to us 35 yrs ago or so. Some has broken (the handles on the mugs were fragile). I have 8 Corelle plates, but we use pottery bowls, and also have some plastic, that we use under way. After many years experimenting with the least expensive of stemware, I have shifted to using juice glasses, like the Basques, for wine. People don't knock them over waving their hands.

Just get what you prefer to eat off of; life's too short to use materials you don't like.

Ann

Something like these Ann?
https://www.potterybarn.com/m/produc...-_-productfeed
OR
https://www.potterybarn.com/m/produc...-_-productfeed

[Lodesman]

Originally Posted by Adelie

You are correct, it is a tempered glass. But it is also more than that.

In tempered glass air is blown over both surfaces of a piece so the outer zones of the piece are cooler than the interior. Once the piece has solidified all the way thru the interior is still significantly warmer than the surface so it will shrink more coming to an even temp and the interior will be in tension and the surface in compression making it stronger than regular glass the same thickness.

The Corelle process uses 2 types of glass in 3 layers. The middle layer has a higher coefficient of thermal expansion/contraction. As a piece cools the middle layer tries to shrink even more than the outer layers do in normal tempering. Consequently there is more latent potential energy in Corelle as well as it being stronger than regular tempered glass.

Do you know this for a fact? I was always under the impression the middle layer was more like annealed glass, to resist the tendency for it to shatter into a billion pieces like normal tempered glass. I don't believe the company advertises much of their trades secret. I've seen Corelle break, and it certainly does not explode. It shatters into random-shaped pieces of various sizes, that I would call sharp, but not as much as normal glass (imo). We've used it for camping, on the boat, and for everyday use at home for the past 20 years.

[boatpoker]

Originally Posted by Lodesman

I've seen Corelle break, and it certainly does not explode. It shatters into random-shaped pieces of various sizes,

I dropped a Corelle plate on our teak galley sole. It exploded and there was no piece bigger than a grain of sugar. I even found some in my hair. It was off the boat that same day.

[clockwork orange]

I use Correlle at home and on the boat, i broke my first piece last week ( at home ) and it sure does shatter as everyone says. It still seems like the best option for the boat to me as while it has a very quality feel it is nice and light in weight which to those of us with light boats this is very important. No interest in stoneware or cast iron skillets.

[wsmurdoch]

Originally Posted by Lodesman

Do you know this for a fact? I was always under the impression the middle layer was more like annealed glass, to resist the tendency for it to shatter into a billion pieces like normal tempered glass. I don't believe the company advertises much of their trades secret. I've seen Corelle break, and it certainly does not explode. It shatters into random-shaped pieces of various sizes, that I would call sharp, but not as much as normal glass (imo). We've used it for camping, on the boat, and for everyday use at home for the past 20 years.

https://ceramics.org/ceramic-tech-to...glass%20layers.

https://www.youtube.com/watch?v=eW8egUCzw-k

Bill
who uses Corelle plates and bowls on his boat along with Titan plastic wine glasses and Tervis tumblers for glasses.

[Adelie]

Originally Posted by Lodesman

Do you know this for a fact? I was always under the impression the middle layer was more like annealed glass, to resist the tendency for it to shatter into a billion pieces like normal tempered glass. I don't believe the company advertises much of their trades secret. I've seen Corelle break, and it certainly does not explode. It shatters into random-shaped pieces of various sizes, that I would call sharp, but not as much as normal glass (imo). We've used it for camping, on the boat, and for everyday use at home for the past 20 years.

I very clearly recall the explanation by my prof after the demo plate exploded, it made a big impression on me and the explanation was neat.

The 2 materials/3 layer bit can be confirmed in WikiPedia. https://en.wikipedia.org/wiki/Corelle

The different thermal coefficients I only recall from my prof.

How It's Made has a video on YT about Corelle, they explain the 3 layers, that some of the ingredients are a trade secrete but do not say anything about the differing thermal coefficients.

https://www.youtube.com/watch?v=0GFGXrf5r5c

https://www.youtube.com/watch?v=vsE-0059kjI

Wikipedia will confirm how tempered glass is manufactured. https://en.wikipedia.org/wiki/Temper...#Manufacturing

[mvweebles]

Stoneware. We purchased high quality from Heath Ceramics in Sausalito. 25 years have yet to break anything.

Porcelain made in Italy and Portugal are usually high quality and very durable.

I don't understand the affection with Corelle. It's thin and feels cheap. First apartment cheap. If anyone wonders why their wife won't cruise with them, start with Corelle and follow the thread of similar compromise decisions guys think are the right thing to do.

Peter

[mvweebles]

Originally Posted by Adelie

Something like these Ann?
https://www.potterybarn.com/m/produc...-_-productfeed
OR
https://www.potterybarn.com/m/produc...-_-productfeed

Guessing more like these. We have been using "Rooster" glasses for years for table wine. Also a juice glass. Both are sturdy

https://www.williams-sonoma.com/m/pr...king%20Glasses

[Bruce K]

Stainless dog bowls, with a non skid rubber ring around the botton. Very stable, unbreakable, can be cleaned by putting over the side in a fish keeper net! Stainless mugs. Fro my days ocean racing in the 70's

[mvweebles]

Originally Posted by Bruce K

Stainless dog bowls, with a non skid rubber ring around the botton. Very stable, unbreakable, can be cleaned by putting over the side in a fish keeper net! Stainless mugs. Fro my days ocean racing in the 70's

Charming!

[Lodesman]

Originally Posted by Adelie

The 2 materials/3 layer bit can be confirmed in WikiPedia. https://en.wikipedia.org/wiki/Corelle

The different thermal coefficients I only recall from my prof.

Corelle confirms the 3 layer laminate:

Corelle® products are created using a special glass lamination process that thermally bonds two clear "skin" layers of glass to a white or beige "core" layer. This proprietary technique is unique to Corelle® - in fact, we invented it!

Nothing about differing thermal coefficients. Any tempered glass is internally-stressed, and this is why tempered panes shatter into glass pebbles. Corelle dishes do not shatter into uniform "pebbles"; they shatter much as any glass piece would into non-uniform pieces. The claim that a piece shattered into sand is, in a word - unbelievable.

We really didn't need the same youtube video posted 3 times, did we? I'm sure if you look around on youtube you'll find some of corelle being broken. If you can find one of a piece "exploding" or turning into pieces no bigger than a grain of sugar, please post it.