How do I repair a broken ceramic or glass item?

Most ceramic repairs go wrong before any adhesive is opened, in the order the pieces get assembled. Ten minutes of dry-fitting is the difference between an invisible line and a piece that no longer goes together.

Safety

What you'll need

• Superglue gel, or a two-part epoxy for multi-piece breaks
• Masking tape, or a box of dry rice or sand to hold the piece
• Cocktail sticks or a scrap of card for spreading
• Gloves, a craft knife and acetone for cleanup

Step by step

1. Collect every fragment before starting.Including the dust and chips. Vacuum the area carefully into a bag and sort it on a light surface. A missing sliver becomes a permanent visible gap.
2. Clean the broken edges and let them dry completely.Warm water and washing-up liquid, then dry thoroughly — porous earthenware needs a day. Adhesive will not bond to a greasy or damp edge and moisture trapped inside pushes it apart.
3. Dry-fit everything and work out the order.This is the important step. Assemble it with no adhesive, numbering pieces in pencil as you go. Get the order wrong and a middle piece will not fit once its neighbours are set.
4. Choose the adhesive for the break.A clean break into two pieces takes superglue gel, which gives a very thin line. Several pieces, a load-bearing repair, or anything needing gap-filling wants a slow-set two-part epoxy, which gives working time.
5. Use a slow epoxy, not a five-minute one.Five-minute epoxy sets while you are still aligning things. A 30-minute or slower grade gives time to position and adjust, and generally cures stronger.
6. Apply as little as possible.A thin film on one face only, spread with a cocktail stick. Excess squeezes out and dries as a visible ridge, and a thick glue line holds the pieces apart so nothing else aligns.
7. Rig a support before you commit.A box of dry rice or sand holds an awkward shape at any angle, and masking tape pulls pieces together. Set this up while the adhesive is still in the tube.
8. Assemble in the order you worked out.Largest and most stable first, working outwards. Let each joint reach handling strength before adding the piece that depends on it.
9. Remove squeeze-out at the right moment.Epoxy is easiest to trim with a knife when it is rubbery — usually an hour or two in. Superglue squeeze-out is best left until hard and then pared carefully with a fresh blade.
10. Leave the full cure.24 hours at minimum, longer for epoxy, before handling properly. The joint feels solid long before it is strong.
11. Fill any remaining gaps.Epoxy putty or a ceramic filler, sanded flush when hard, then touched in with acrylic paint and a fine brush. Match the sheen with a matt or gloss varnish over the top.
12. Accept the item is now decorative.Not food-safe, not dishwasher-safe, not for hot liquid, unless the adhesive is explicitly rated and it rarely is. Displaying it is the honest outcome.
13. Consider a professional for anything valuable.A ceramics conservator can do reversible, invisible work on something with real value or sentiment. A DIY repair with epoxy is permanent and can reduce what a conservator can achieve.
14. Or make a feature of it.Kintsugi-style repairs deliberately highlight the join with a metallic line. A legitimate choice, and easier to do well than an invisible repair.

Tips

• Dry-fit and number the pieces in pencil first. Nearly every failed multi-piece repair is an assembly-order problem.
• A box of dry rice holds an awkward shape at any angle while it cures, and costs nothing.
• Use slow epoxy rather than five-minute. The extra working time is worth more than the wait.

Common mistakes

• Gluing pieces as you pick them up — Without dry-fitting, a middle piece is left over that no longer fits once its neighbours have set. The repair then has to be broken apart.
• Using too much adhesive — Excess squeezes out into a visible ridge and holds the pieces apart, so nothing else lines up. A thin film on one face is enough.

If it doesn't work

Questions people ask