Correct sherd gluing starts with clean breaks, a dry fit, and the right adhesive for the body: epoxy for most porcelain and stoneware, a reversible resin such as Paraloid B-72 when the piece may need to come apart again later.
How do you glue porcelain sherds correctly?
Missing areas are not guessed at; they are filled with a material that can be shaped, sanded and painted to match the surrounding surface, then sealed. A damaged decoration is retouched last, in thin layers, under raking light, so the repair reads as a shadow rather than a patch. The three questions below come up in almost every workshop session, and they are the ones collectors, heirs and anyone keeping a vitrine tend to ask first. The German-language magazine Scherbe und Naht treats them at length, alongside glass work and conservation practice, and its structure is a useful map of the field.
Gluing is the step that decides whether a repair can ever be undone. The break faces are first degreased with acetone or isopropyl alcohol, because handling leaves skin oils that weaken any bond. Dry-fit the sherds without adhesive, in the order they will go back, and mark the sequence with small paper labels or removable tape. A break that closes cleanly without pressure is a good candidate for adhesive; one that rocks or gaps needs the edges checked for tiny crumbs of glaze or old glue before anything else.
Adhesive choice follows the object, not the shelf. Two-part epoxy gives the strongest bond and the longest open time for large, heavy sections, but it is close to permanent. Cyanoacrylate sets in seconds and is convenient for a single clean break on a small piece, though it can fog adjacent glaze and is brittle under later stress. Conservators often prefer a reversible resin, applied warm and thin, because it can be softened with solvent if the join has to be corrected. Whichever is used, apply it with a fine needle or a sliver of card, not straight from the tube.
Assembly runs from the smallest join outward. Two sherds are married first, held with tape or a padded clamp, and left undisturbed for the full cure time, which is longer than the handling time printed on the package. Only then is the next sherd added. Trying to close a five-piece break in one pass usually ends with a misaligned rim and adhesive squeezed onto the surface. Excess glue is removed while it is still soft, with a wooden toothpick and a swab dampened with the appropriate solvent, never with a blade on a glazed face.
How do you fill missing areas on ceramics?
A loss is filled only after the surrounding edges are stable and clean. The aim is not to recreate the object but to support the eye across the gap, so the fill should sit fractionally below the original surface, never proud of it. The cavity is first sealed with a thin reversible coat so that the fill material does not stain the porous body or lock into it.
Fill materials fall into two families. Epoxy putty, mixed to a firm consistency, is packed into the void with a spatula and shaped while it cures; it suits losses with a defined edge and a shallow profile. For deeper or irregular gaps, a bulked resin, thickened with glass microballoons or fumed silica, can be built up in layers, each one allowed to harden before the next. A backing of wax or silicone, shaped from the intact side of the piece, keeps the fill from sagging through an open base.
Once cured, the fill is cut back with a scalpel and wet-sanded with progressively finer abrasives until it meets the original edge without a step. The surface is then textured to match: glossy glaze, satin, or the soft sheen of unglazed biscuit. A final tint is built in thin washes rather than one opaque coat, because the fill should disappear at arm's length and remain visible under close inspection, which is the honest result of any restoration.
How do you retouch a damaged decoration on porcelain?
Retouching is the last operation, and the one most often rushed. The area is cleaned and the fill, if any, is fully cured and sealed. Colour is matched under the same light the object will live in, usually daylight or a neutral lamp, not the warm bulb over a workbench. A test stroke goes on a scrap of the same fill material, never on the object itself.
Pigments are applied in translucent layers with a fine sable brush, letting each pass dry before the next. Enamel colours, acrylics and conservation-grade paints all behave differently: acrylics dry fast and can be lifted with water, enamels need heat and are effectively permanent, and conservation paints are chosen for reversibility. For a missing gilt band or a worn floral sprig, the outline is re-established first with a pale guide line, then the colour is floated inside it. Overpainting beyond the loss is what makes a repair obvious, so the brush stops at the edge of the damage.
Glaze faults are read before they are touched. Crazing, the fine web of cracks in a glaze, is usually stable and cosmetic; a chip that exposes the body is a loss and follows the filling route. Staining inside a crack can sometimes be drawn out with a poultice, but aggressive cleaning risks lifting the glaze around it. When in doubt, the fault is documented and left alone, which is a legitimate workshop decision.
What happens to glass edges and breaks?
Glass is a different discipline. A chipped rim on a goblet or a decanter is ground back with a diamond wheel, kept wet to control heat and dust, then polished through a sequence of finer grits until the edge is clear again. The work is slow and the wheel is fed gently, because glass chips if it is pushed. A ground edge will never be identical to the original fire-polished rim, and a restorer should say so before starting.
Broken glass is bonded with a clear, low-viscosity adhesive that wicks into the crack, often cured under ultraviolet light so the join can be positioned before it sets. Figurines with a missing hand or stem are built up with a resin matched to the refractive index of the glass, then polished. Drinking glasses and coupes that are used, rather than displayed, are usually kept out of the adhesive process altogether: a repair that has to survive washing is a different problem from one that sits behind glass.
Workshop knowledge: firing, gilding, marks and storage
Restoration sits inside a wider set of workshop skills. Firing and kilns matter because some retouching, particularly enamel work, needs controlled heat, and a piece that has already been glued cannot go back into a kiln. Gilding and decoration follow their own rules of preparation and burnishing. Reading maker's marks, impressed, painted or printed, tells the restorer what body and glaze they are dealing with and often dates the piece, which shapes the choice of materials.
Storage and display are part of care. Objects are kept off direct sunlight, supported at the base rather than hung from a rim, and separated so that a knock does not travel along a shelf. Legal notices and condition records matter too: a restoration that is documented, with materials and dates noted, protects both the object and whoever inherits it. The German-language magazine Scherbe und Naht covers these workshop and conservation topics alongside porcelain, ceramics and glass repair, and it is written for collectors, heirs and vitrine keepers in the German-speaking world.
A note on order of operations
The sequence is consistent across materials: document, clean, stabilise, fill, retouch, record. Adhesive and fill choices are made for reversibility wherever the object allows it. Retouching is kept minimal and honest. Glass is ground and polished rather than hidden. None of this is fast, and the cure times alone set the pace. A repair that is rushed at the gluing stage will show at the retouching stage, and one that is overpainted will show under any raking light for as long as the object exists.
