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Ceramic welding: guide and FAQ

How ceramic welding repairs a glass furnace while it is hot, where it is used, and answers to the questions glass makers ask most.

The technique

What is ceramic welding?

Ceramic welding is a hot repair technique for refractory. A dry mixture of refractory oxide powder and fine metallic fuel is carried by a stream of oxygen through a lance and blown onto the hot refractory. The fuel burns in the oxygen and the heat released, above 2,000 °C, melts the surface of the oxide grains: they fuse with one another and with the existing block, forming a new ceramic layer that is bonded to the wall, not simply stuck onto it.

Because the reaction needs a hot surface, the repair is made at operating temperature. The furnace is not cooled or drained and, in most cases, production continues while we work. The powder is chosen to match the refractory being repaired, so the new material behaves like the original block.

Where ceramic welding is used in a glass furnace

  • Crown: eroded areas, open joints and holes
  • Breast walls and sidewalls of the superstructure
  • Ports and burner blocks
  • Tuckstone areas, just above the glass line
  • Regenerators: walls and crowns
  • Expansion joints and minor damage, sealed from the outside

Ceramic welding repairs the superstructure, the refractory above the glass line. The glass-contact zone below is repaired with our patented Hot Tank Repair (HTR®).

Why glass makers choose ceramic welding

  • No cool-down: the furnace stays at temperature, with none of the thermal stress of a shutdown and restart.
  • Production continues in most cases, so the repair does not cost weeks of lost output.
  • A dense, bonded repair, compatible with the original refractory.
  • Precise: material goes only where it is needed, guided by endoscopy.
  • A longer campaign: damage repaired early does not grow into a failure.

How an IRF ceramic welding job works

  1. Inspection. A hot endoscopy and thermal imaging show where the refractory is worn, and how much.
  2. Planning. A site visit or a review of your drawings lets us design the lances and choose the powder for each area.
  3. Repair. Our qualified teams weld with IRF's own machines, in-house cooled lances and high-purity powders, in close contact with your operators.
  4. Check. The repaired areas are inspected again, so you can see the result and plan the next intervention in time.

Ceramic welding: frequently asked questions

Can ceramic welding be done while the furnace is in production?

Yes. Ceramic welding needs a hot surface, so it is carried out at operating temperature and, in most cases, without stopping production. The work is planned together with your production team.

Which parts of a glass furnace can be repaired?

The superstructure: crown, breast walls, ports and burner blocks, tuckstone areas and regenerators. From the outside, ceramic welding also seals expansion joints and repairs minor damage.

Which refractories can be repaired?

The powder is matched to the refractory being repaired. In glass furnaces this is most often silica and AZS, the main materials of the superstructure.

How is ceramic welding different from hot gunning?

Gunning sprays a refractory mix held together by a binder. In ceramic welding the grains are melted and fused to the existing block, which gives a denser repair that is bonded to the original refractory.

Can ceramic welding repair the glass-contact zone?

No: below the glass line the refractory is repaired with our patented Hot Tank Repair (HTR®), which renews the glass line hot without draining the furnace.

How long does a ceramic welding repair last?

It depends on the area, the extent of the damage and the furnace conditions. Regular endoscopies show how the repaired zones are behaving, so further work can be planned before it becomes urgent.

Who carries out the work?

IRF was founded in 2008 as a ceramic welding specialist. Today our own qualified teams work from 10 countries for glass makers all over the world, with ISO 9001 and ISO 45001 certification.

Need ceramic welding? Let's talk.

Wherever your furnace is, our qualified teams respond quickly, for planned work and emergencies alike.

Contact a teamCeramic Welding