IGU Low-E Edge Deletion Verification Inspection

Inspection template for verifying low-E coating edge deletion on insulated glass units (IGUs) so the secondary sealant bonds to bare glass and seal adhesion failures are prevented.

Inspection Setup and Unit Identification

• IGU job, lite count, and coating specification match the traveler or work order
  Verify the unit identification, glass make-up, coating side, and edge deletion requirement against the production traveler or specification.
• Inspection performed at the correct process stage before secondary sealant application
  Confirm the unit is being checked after edge deletion and before the secondary seal is applied.
• Inspection tools available and suitable for verification
  Confirm the inspector has the required tools such as a light source, ruler or caliper, and magnification if used by the site SOP.
• Glass surface is clean enough to evaluate the edge deletion band
  Verify dust, oil, water, or debris are not obscuring the perimeter area being inspected.

Edge Deletion Width and Continuity

• Edge deletion width meets specification around the full perimeter
  Measure the exposed bare-glass band at representative points on all sides and confirm it meets the required width per product specification.
• Edge deletion is continuous with no unremoved coating bridges
  Inspect the perimeter for any remaining low-E coating that crosses into the seal area or interrupts the bare-glass band.
• Corner areas are fully cleared to bare glass
  Check all corners for coating remnants, narrow spots, or incomplete deletion where sealant adhesion could be compromised.
• Deletion band is uniform and does not vary beyond site tolerance
  Assess whether the edge deletion width remains consistent enough to support reliable sealant bonding across the perimeter.

Surface Condition and Seal Bond Readiness

• Bare-glass deletion area is free of coating residue and visible contamination
  Verify the exposed glass band is clean and does not show smeared coating, dust, fingerprints, or other contamination that could affect bond performance.
• No scratches, chips, or edge damage are present in the seal area
  Inspect the deletion band and adjacent edge for damage that could interfere with secondary seal adhesion or unit durability.
• No visible coating haze or partial removal remains in the seal area
  Confirm the seal zone is fully exposed bare glass and does not contain haze, ghosting, or partially removed low-E coating.
• Surface condition supports secondary sealant adhesion
  Rate the overall readiness of the deletion area for sealant application based on cleanliness, continuity, and exposed bare-glass condition.

Documentation and Corrective Action

• Measured deletion width and inspection results recorded
  Document the measured width, pass/fail result, and any observed non-conformance for the inspected unit.
• Any non-conformance is clearly described with location on the lite
  If a deficiency is found, record the exact side, corner, or area affected so rework can be targeted.
• Corrective action assigned for any edge deletion deficiency
  Document whether the unit requires rework, re-cleaning, re-deletion, hold for review, or scrap disposition per site procedure.
• Inspector name and completion time recorded
  Capture who completed the inspection and when it was performed for traceability.