A porcelain repair or restoration is something you may face earlier or later if you are handling lots of antique porcelain or pottery.
Unless you are always extremely careful a piece may knock a hard object or another porcelain item, and crack or break. It happens to all of us...
If your porcelain item is valuable or rare, then you may want to repair it. However, a do-it-yourself porcelain repair is not advisable in general,unless you are of a more adventurous nature and risk a botched job, or if you are seriously learning the trade.
Special glues required for prefessional porcelain repair, and worldwide there may only exist a handful or so different glues suitable for this specialized purpose. They are very expensive. The glue at your hardware store that says it can be used for gluing porcelain or ceramics is not one of these!
Avoid repairing porcelain with porcelain glue sold at your local hardware store, it may not be suitable. These glues often will turn yellow after some time even if they are transparent at the beginning, and they may not be thin enough for the job.
Some glues used by restorers have a viscosity and consistency that is more like water. They need several days to cure completely, but also allow repositiong of shards within a reasonable amount of time. The special tools required for handling such repairs may also not be in the range of a DIY job.
If you decide leaving the task to a professional porcelain restoration service or restorer, it may cost more, but in many cases the repair will be almost or completely invisible afterwards. Restorers will fill in missing pieces and repaint the decoration.
Soiled surfaces need to be cleaned first before any restoration or repair can be done. Shards need also cleaning if the restorer needs to disassemble an old repair.
The broken lid of the 19th century medicine jar shown on the right is the result of careless handling. Lids and loose parts drop most easily. The fact that many antique tea pots and jars have their lids missing says it all.
The cleaning process may take quite some time as the pieces may have to be immersed in cleaning water for some time, and after cleaning they need to be left to completely dry for many days. In case of pottery the drying time is even longer. A repair can only beginn after all pieces are dry.
A restoration complete with cleaning, repair, filling, and re-painting will usually take a couple of weeks, at least, often a month or two to complete.
What to do after breaking something
After breaking any ceramic item the first thing to do is to pick up all broken pieces, even the small ones, and wrap them up. This not only ensures that none are lost, but it also prevents soiling of the breakage surfaces.
Restoration
There are three types of restoration.
Commercial restoration
Museum restoration
Research restoration
Of the above three a commercial restoration is the most demanding. The purpose of this is to restore the look of a piece as nearly as possible to its original state. Such a restoration may be hardly or not at all visible. Aesthetic value is the most important. The decoration and glaze will be restored and sometimes a low temperature firing performed. Porcelain restored this way will usually be for sale, or for a private collection.
A museum restoration is for the purpose of display. Usually, any mended places remain visible and there is a requirement of reversibility of the restoration.
Restorations for research have the least requirements due to their purpose, which is mainly to establish the look, shape or use of an item.
Some glues used by restorers have a viscosity and consistency that is more like water. They need several days to cure completely, but also allow repositiong of shards within a reasonable amount of time.
