Pat Fulton of Clarence, NY relates her experiences with crazing

Crazing or crizzling of glass is a glass anomaly which I found rather fascinating several years ago and that led me to actively seek out “sick” pieces of glass so I could study them.
Some pieces flaked and chipped, others simply became more crazed and a few didn’t change at all. The most interesting piece (to me) felt sticky and no amount of washing or cleaning took that sticky feeling away.
Two different explanations of what caused the sickness were given to me, the first was improper annealing caused the sickness and the other was an improper chemical balance in the batch of glass. After many inquiries I still do not know if only one or both of reasons is the cause of the sickness.

If my work schedule allows me to attend the symposium this year I’ll bring a sick, sticky, crazed piece of glass with me to share.
Scott Hansen, Chairman of this year’s Symposium, take note of Pat’s last paragraph. Yes, lots of interesting things and exchanges take place at a Symposium.

Rande Bly’s experiences with crizzling:
Thank You Ed Bush. Finally after 20 years I am satisfied with the crizzling effect. If it was a problem with hard water then how was it showing up on the outside of the foot of these pieces. If it was worse when the piece was stored long times in an area where condensation was higher(close to the lehring ovens) the condensation should not be high in minerals. Things were not adding up. Your explanation explains it all. A reason for it to be on the outside of pieces and worse on the inside like the Bristol Fan vase Marshall spoke of.. Again, once I saw a piece that had the crizzling effect so evenly that it did look intentional and was actually quite pretty. First time I saw it I thought Mr. Carder had invented Microscopic Glue Chip! tee hee
Recall the Ed Bush got his definition from David Whitehouse’s dictionary of glass. Dr. Whitehouse is the director of the Corning Museum. His glass dictionary can be purchased from the Museum gift shop. If you belong to the Carder Steuben Club you get a companion membership in CMoG and from that membership which the Club purchases for you, you are entitled to a discount that I think is 15% at the CMoG gift shop.

Finally, Gail Bardhan at The Rakow Library adds some more information on crizzling.
I thought that the group might be interested in a more on the glass which many call “sick”. It is really called crizzled glass. From the glass dictionary of the Corning Museum of Glass:
Crizzling: The result of chemical instability in glass caused by an imbalance in the ingredients of the batch, particularly an excess of alkali or a deficiency of stabilizer (usually lime). The instability of the glass results in an attack by atmospheric moisture, which produces a network of cracks in the surface that may feel damp or oily. Crizzling can be slowed or perhaps even halted, but it cannot at present be reversed. Crizzled glass is sometimes described as “sick” or “weeping.”
If anyone wishes to pursue this a bit further, our website www.cmog.org, under the section glass resources, has a section on crizzling and the preservation of glass; the library has even more information.

Regarding the comment that glass is a liquid, and that over the years a pane of glass in a window will become thicker at the bottom and thinner at the top is one of those “urban legends”. Once again, go to our website, and section on glass resources, and look at the information “Does Glass Flow?”, compiled by our research scientist Bob Brill.

Gail Bardhan
Reference & Research Librarian
The Corning Museum of Glass
Five Museum Way
Corning, NY 14830
Telephone 607-974-8020
Email bardhangp@cmog.org