All toilets are glazed when they are manufactured, giving them their characteristic shine. This glaze covers the fixture's porcelain exterior. Some manufacturers install a special glaze over the toilet, designed to offer additional protection from dirt and bacteria. Other toilets have trapways that are fully glazed; the trapway is the passageway inside the toilet, through which water and waste travel to reach the drainpipe.
A fully-glazed trapway is often a feature that consumers seek out. This type of trapway allows a smoother exit path for water and waste. This smooth passage is a valuable asset in reducing the amount of dreaded clogs that toilets experience. The trapway's outline is normally noticeable on the base of the toilet bowl, near the rear. It is the curved passage that leads down towards the floor.
Special Glazed Toilets
The glaze over toilets gives the toilet a more radiant appearance, and a smoother feel. Some manufacturers, such as Toto, go one step further with the company's patented SanaGloss protection. The glaze on any toilet basically provides a seal for the toilet's surface against the growth of germs and bacteria. The SanaGloss glaze provides additional protection for the vitreous china of certain Toto toilets, protecting against the buildup of dirt particles and bacteria, that would otherwise occur. The glaze actually repels debris, making cleaning the fixture simpler and faster.
Protecting Toilet Glaze
When normal cleaning duties are performed on a toilet, the glaze should not wear off or dull. To preserve the fixture's full luster, be sure to use the correct materials and cleaners, while avoiding those that are too abrasive. When in doubt, always follow the toilet manufacturer's instructions for what products to use. For daily maintenance, no cleaner is needed. Simply scrub around the water line and rim holes inside the bowl with a toilet brush, or wipe the exterior with a sponge or old rag, where necessary.
Low Flow and Glazed Trapways
More modern toilets are also using fully-glazed trapways because of water usage restrictions. Toilets manufactured since the mid 1990s are required to use less water for each flush. Gravity toilets, the most popular models, combine the volume of water with gravity to fully flush the toilet bowl. A lower volume of water reduces the power of that flush. Older toilets used 7 or 3.5 gallons of water per flush, while today's toilets are required to use a maximum of 1.6 gallons per flush. Some toilets use even less water, such as 0.8 gallons per flush. An early knock against these low-flow models was their tendency to clog. That complaint has since dissipated, as low-flow models have improved. A fully-glazed trapway further aids these low-flow toilets in flushing completely.
Adding Glaze Yourself
Toilets are glazed when they are manufactured. The fixture is heated in a kiln, fusing the glaze to the toilet. The average consumer is unable to duplicate this process, unless they have access to a kiln. If portions of the toilet have lost the original luster, due to chips, cracks or poor maintenance, use a plumbing refinishing kit or plumbing refinish spray. These are designed to restore the finish on toilets, tubs and sinks, and are usually available online or at local home improvement stores.