Furnace Lining Repair and Surface-Preparation Checklist

Entry criteria from diagnosis

Start with a traceable defect map and an approved disposition for each repair zone. Cracks or movement requiring engineering review remain outside the repair release until that review is complete.

Identify the lining and repair boundary

Record the lining or refractory identity where known, previous repair edges, substrate changes, anchors, joints and penetrations. Mark a repair boundary that reaches stable material and can be prepared, placed and inspected without concealing an uncertain edge.

Mark unsound and uncertain zones

Use location IDs and photographs to separate visibly loose, cracked, hollow-sounding, contaminated and inaccessible areas. Do not classify uncertain material as sound merely to keep the planned repair small.

Remove material without enlarging hidden damage

Remove only under the approved repair method, working toward a stable boundary while observing what the exposed interface reveals. Stop and escalate if removal uncovers unexpected depth, movement, anchorage issues or a different substrate.

Prepare sound edges and joints

Clean repair faces and edges while preserving intended joint function. Remove dust and loose debris, then inspect the actual prepared condition before repair material is placed.

Treat transitions and penetrations

Define how the repair terminates at metal, refractory changes, anchors, sleeves, openings and earlier repairs. A transition must accommodate its intended function and remain inspectable rather than being buried beneath a continuous cosmetic finish.

Confirm repair-material compatibility

Use the approved repair specification and verified substrate information to confirm compatibility. Where lining identity, contamination or an earlier repair is uncertain, require evidence or a controlled trial instead of making a proprietary compatibility claim.

Place and finish the repair

Follow the authorized repair procedure, maintain the marked boundary and avoid trapping debris or creating inaccessible voids at edges and details. Record interruptions, deviations and areas that need rework before the surface is accepted.

Cure and heat-up handoff

Transfer the completed repair into the specified curing and return-to-service process with material identity, placement time, environmental record and deviations documented. Do not invent or generalize a heat-up schedule; use the approved repair and operating documents.

Repair acceptance

Accept the repair in a sequence that preserves what was checked and by whom.

Record nonconformities

Keep the original observation, agreed disposition, repair record and reinspection together. Do not erase the history of a rejected edge, contaminated area or interrupted repair by replacing it with a final photograph.

Release for the functional layer

Release only accepted repair zones whose surface condition, joints, compatibility evidence and cure status meet the approved work package. The functional layer should not be used to hide an unstable repair or unresolved lining defect.

Scope limits

This checklist does not diagnose crack causes, certify structural condition, define numerical acceptance limits or select a coating product. Those decisions belong to the preceding investigation and the project-specific engineering and technical documents.

Related technical pathways