Thanks to all the readers who gave advice about the disintegrating art pottery we wrote about in last week's tip. They suggested the cause was mice, hatching insect eggs, termites, pressboard or Chinese drywall fumes, or an old chlorine bleach cleaning. Other suggested causes include a change in humidity or altitude or temperature. Or possibly the pottery froze while being shipped; then when it defrosted, it chipped. And don't ignore the possibility of old repairs. Here are a few of the most interesting suggestions in the blog. We haven't tried any of these, so be careful. For more, go to (Tip, March 3).
Petercdale, in two posts, said:
It sounds like the pottery was washed in a bleach-like liquid. You must cut off the air around that. A first good step must be to spray a clear lacquer glaze in matte and/or gloss over the whole piece inside and outside. This seals the item from air that is probably causing crystals to form through the normally unseen craze lines and under the outer layer of glaze. The crystals form from the digestion of the middle layer of clay. Pottery and similar items are formed in 3 layers--outside glazing, than clay, and then by inner glazing.
This also may have contributed to the problem: The difference in expansion/contraction characteristics which has the inner layer of clay expanding and contracting at a different rate than the inner/outer glaze does. This forms the craze lines you now see. So it could be the combination of craze lines absorbing cleaning liquids that force the outer glaze to crumble. Again, wipe it carefully to knock off any loose stuff, then spray them. The lacquer glaze easily comes off later by dipping in acetone, lacquer thinner or MEK. Lacquer thinner of the three is my choice. Observe the warnings on the chemical cans and lacquer spray glaze can and wear rubber gloves and approved mask. These may all be available in an auto supply store (Pep Boys or Auto Zone or a pro paint store). Good Luck.
John wrote: One of my customers had the same thing happening. She found out that her grandchildren were throwing darts at the wall!!
Anonymous said: Could this be related to the corrosive effects of Chinese-manufactured drywall? See links below.