Thanks for the question. Ceramics like porcelain and vitreous china are typically quite receptive to adhesive bonding, but there are a few things to consider.
One of the most important considerations is the substrates to be bonded. If you were attaching a non-ceramic material to the ceramic, a flexible adhesive or high strength tape could be used to isolate the stresses on each component. This is a common design choice for outdoor applications where temperature changes cause the materials to expand differently. For ceramic to ceramic bonding (such as crack repairs), a rigid adhesive is typically a good option.
Two common options for ceramic crack repair are epoxies and cyanoacrylates (instant adhesives). Cyanoacrylates are convenient, but they tend to have low moisture resistance. So, for a wet environment like this, you’ll probably want to try an epoxy instead. 3M™ Scotch-Weld™ Epoxy Adhesive DP100 Clear is one example of a rigid epoxy with low viscosity that might work in a ceramic repair application. I’ve attached a datasheet below for your consideration.
Some important notes: First, 3M™ Scotch-Weld™ Epoxy Adhesive DP100 Clear (like many adhesives sold by the 3M Industrial Adhesives and Tapes Division) is for industrial/occupational use only. It is not for consumer sale or use. It is also not intended for either direct or indirect food contact applications, which may be relevant to certain ceramics. Second, ceramic repair can be quite tricky to do well, particularly with fragile and/or aged ceramic. Depending on what the fracture and substrate looks like you may need to do something to widen the crack before applying an adhesive so it has good contact between the surfaces.
We’d be interested to hear if anyone has suggestions on this type of process.