Dissolving old glue
Often, the old adhesive will darken over a long period of time. The only advice for this kind of discoloration, for crookedly glued fragments or for remnants of hardened glue left on the surface, disassemble the entire object, cleaning of the old glue and gluing it again.
Dissolving in water
Animal-based brown glue can be dissolved by immersing the entire object in hot water. The same can be done with polyvinylacetate glue. In order not to damage the fragile ceramics, wrap the vessel in a piece of cloth or a sponge mat and place it in a plastic basin with warm water, then gradually add hot water.
As the glue softens, remove it with the little one, with a stiff brush or toothbrush. Check it out, that all the pieces fit together perfectly. if not, check it out, that there are no residual glue on the edges. Brush them off with a brush or pry them off with the tip of a knife.
Dissolving in denatured alcohol
Winds, also brown in color, often dissolves in water. However, if this does not happen, place denatured cotton swabs along both sides of the joint. Change the swabs, until the spirit soaks deeply and the edges come apart. If this method also fails, use paint solvent.
Dissolving in acetone
Acetone-soaked swabs placed on both sides of the joint will dissolve cellulose glue and polyvinylacetate glue. Acetone evaporates fairly quickly, so you have to wrap the whole thing in plastic wrap, so that the swabs do not dry out.
Dissolving with a paint solvent
Solvents soften modern epoxy resin and rubber adhesives, however, they can destroy the patterns painted on the ceramics. If the previous restoration was sloppy, be happy about it; generally, however, we want to keep the old paint. So, if it's possible, apply solvent only from the inside. The solvent must be washed off immediately after the adhesive softens, so that it does not get to the outside.
Before using the solvent, soak the dish in water.
Warning: protect hands with gloves when using chemical solvent, strictly follow the manufacturer's recommendations and avoid contact of the liquid with the skin. Move the brush away from you, so that the solvent does not splash into the eye. Never wash off the solvent with hot water, to avoid the formation of toxic fumes.
