Repairing pottery and china can be surprisingly easy once you know a simple trick or two. You will need a small brush, adhesive, some rice or sand, a plastic food-storage container, and a razor blade or two.
The best adhesive for pottery repairs is white glue (PVA or polyvinyl acetate). Use a small throwaway brush to apply a thin, even coat to both of the cracked edges; then quickly join the pieces together. Be careful not to shift them as they are joined. Doing so could chip fine edges and cause small particles to break loose. Excess glue should be removed, but not during the first hour following the repair. Create a positioning box to balance the piece so that its own weight will assist in the mending process. Such a box can be made by placing dry rice, beans or sand into a container large enough to stabilize the object being repaired. After the joint dries for an hour, use a razor blade to carefully scrape away the excess glue. Then, use a cotton swab dipped in hot water to get rid of any residual glue. The piece being repaired should remain in the positioning box for a minimum of 24 hours.
REMEMBER: Too much glue will prevent a tight joint and not enough will result in a poor bond. There is a delicate balance required here. Crystal is repaired in the same manner as pottery except that the adhesive should be a clear, slow-drying, two-part epoxy. Lacquer thinner on a cotton swab should be used to remove the excess epoxy from around the mended joint. Lacquer thinner is not the same as turpentine or paint thinner; and, they are not interchangeable.
We have some good news, and some bad. By using our process a family heirloom can be saved, but it will require special attention after the repair has been made. Temperatures above 200ºF will soften most glues. Therefore it is important not to place repaired pieces in an oven. And, although a dishwasher does not get up to 200ºF, repeated exposure to hot water and harsh detergents will soften the adhesive. Hand-washing is the safer alternative. By the way, even though it may be safe to use repaired items with food it is not recommended.
To repair shallow chips (a quarter of an inch or less in depth), mix a small amount of clear, slow-drying epoxy with an oil-base hobby enamel to create a shade that closely matches the color of the area to be fixed. Use a toothpick or a small stick to blend the concoction. Again use a very small stick or a toothpick to dab the liquid into the chip. Smooth it until it's even with the surrounding surface, and let it dry for 48 hours.
If an object has broken into more than two pieces it will be necessary to determine the order of assembly sort of like a puzzle. This should be done by gathering the pieces to determine which two should be assembled first and so on so that each piece will fit easily into place. Only two pieces should be reassembled at a time. Make sure that glue is immediately removed from other break edges. Dried glue in these locations could prevent the remaining pieces from fitting together tightly.
WARNING: Wear thick, sturdy gloves when handling broken pieces of pottery, ironstone, porcelain, china or glass; their sharp edges can cause extremely serious cuts. When we were kids our father was making a window repair without gloves. He cut his wrist and had to have six stitches.
When using adhesives, lacquer thinner, paint thinner, enamel paints or any other compound that contains toxic chemicals, it is wise to work outside where there is plenty of ventilation. And, keep such products away from an open flame.