Ceramic Glaze Defects

Poor application of the raw glaze to the bisqueware can lead to various glaze defects.

Ceramic glaze defects.

The most reliable way to check glaze thickness is with a thickness gauge which can be purchased through an instrument supply catalogue. Design lead glazed pieces so that they won t be used for food or drink. Read on to get some expert pointers on how to solve five of the most common pottery glaze defects such as crawling shown at above. Hold the gauge on the surface of the glaze.

In both crazing and shivering the eradication of problems relies on matching the. Lead glazes should only be used on non foodware items. If the glaze does not state lead free or leadless on the label assume it contains lead until proven otherwise. A large bubble sometimes present as a fault in ceramic ware.

The surface of the glaze is very unpleasant and looks like a boiled mass of bubbles craters and pinholes. Applying glaze too thinly can result in rough glazes and can affect the glaze s color. Damage damage describes defects made through use handling cleaning or storage. Glaze defects are any flaws in the surface quality of a ceramic glaze its physical structure or its interaction with the body.

Crazing is the most common glaze defect and normally the easiest to correct. Lead glazed pottery should be labeled as lead containing. Applying glaze too thickly can cause the glaze to run off the pot weld lids to pots and pots to kiln shelves and can result in blistering. The thermal expansion of the glaze is too close or higher than the body.

Glaze surface defects blisters. Glazes that are applied too heavily or too lightly are the cause of any number of glaze defects including pitting crawling color variation and rough spots. Crazing consists in the appearance of network of cracks in the glaze. An adjustment of the dilatation of either the body or the glaze is required.

Welcome to understanding pottery chapter 19. 1 body glaze interaction problems 1 1 crazing 1 2 peeling 2 metal release 3 glaze surface defects 3 1 blisters 3 2 crawling 3 3 metal marking 3 4 pin hole 4 references 5 external links glaze defects can be as a result of the incompatibility of the body and the. Defects in fired ceramics can originate with the clay the glaze. Blue ridge pottery for example is well known for glaze pops.

There seem to be so many ways that bad things can happen to good pots. Glaze defects such as blistering are quite common when firing pottery and can be down to many things clay body glaze receipt firing method and cycle. Jennifer poellot harnetty editor.