This relates to the combustion of burning glaze. There are two ways to coat with glaze ceramic objects. First, the glaze coated on a ceramic objects that have been burned biscuits and burned back to ripen glaze and biscuit. Second, the glaze coated on raw objects (unbaked), which means the ripening glaze once implemented along with the maturation of clay. The second way is called a single combustion (single firing).
Glaze materials used are bahanbahan low temperature glazes or medium temperature. Temperature glaze materials adapted to the temperature of cooked clay lining. In principle, glaze materials for objects that have been burnt biscuit with objects raw (unfired) is the same. Factors that more essence is that the glaze should adhere well to the body of the object without peeling. Pengglasiran first done on the inside of the object, and then the outside.
Pengglasiran done quickly, and be careful when lifting / handling, must be done with caution as the raw power of objects depends on the strength of clay. Often there cracks / broken so pengglasiran process is completed.
a. Single Combustion Process
In principle, a single combustion process similar to the process of burning the biscuits. While the principle of the preparation of raw glazed objects together by arranging objects Glazed biscuits. Initial burning must be done very carefully, and carried out the same as in the combustion tahaptahap biscuits. During combustion required ventilation holes enough to provide an outlet for the hydrocarbon gas from the body object.
Single combustion is a combustion combination of combustion and combustion biscuit glaze, so it takes a long time, compared to just burning the biscuits. The interaction between the body and the glaze will become larger than the object pengglasiran biscuits, because the body will absorb a ceramic glaze.
b. Advantages and Disadvantages
Single combustion advantages are:
1) Efficient in terms of fuel use, either with fuel oil, gas or electricity.
2) Operational costs can be reduced, it is very different when done by burning twice.
3) Furnaces tend to be more durable.
Losses single combustion are:
1) If the object is not burned raw Glazed in accordance with procedures, the gas separated perfectly, these gases can evaporate and penetrate / splitting the glaze. When this happens there will be brindle called crawling.
2) When the initial burning object is broken, and the fragments spread around, then the fraction will be attached to other objects when the glaze has become mature.
3) Damage caused by single firing technique are: the glaze jumping, weight ballooned, and there are air bubbles in the glaze.