DSS-Co.05.02 — Pinholes / Voids (Ceramic Frit)

Frit pinholes/voids are discrete, point-like clearings or ultra-thin spots occurring within a fired ceramic frit pattern (dots/lines/solid fields). From the viewing face they appear as tiny bright/clear points in transmission or sparkle points in reflection. The defect is planar within the frit layer (commonly on #2 or #4) and non-tactile at the viewing surface. Classification is appearance-only per VIS (method-agnostic). Inspect after Non-Invasive Reveal at the viewing face under VIS lighting/geometry; record surface numbering and worked-surface status.

System ID is critical. Verify frit location (surface #), pattern specification (dot size/spacing/coverage), vision vs. non-vision zones, and intended tolerances (shop drawings/submittals).

• Isolated or clustered clear points typically 0.1-2.0 mm diameter, occasionally larger where solvent pop or trapped air discharged.
• Constellations may align along application direction, screen edges, or contamination trails.
• Under back-lighting pinholes present as bright windows; under broad specular they sparkle against the frit field.

Surface-catch class (MSRT)

• At the viewing (glass) surface: SC-0 (defect is behind the viewing face in the frit layer).
• Do not MSRT the frit face in situ. MSRT supports classification only on the viewing face.

Visual signature

• Sharp-edged clear points inside the frit region; no chip-flank sparkle, no grooves/pits on the viewing surface.
• Size distribution within a cluster is often narrow; repeatability across lites suggests process origin (screen/ink/wet-film/cure).

Viewing / lighting

• Evaluate clean & dry at 12 / 36 / 72 in, normal and oblique sweep (~60°-120°); capture back-lit frames (ambient interior lighting) and raking macros to verify smooth viewing face. Record distances/angles in-frame.

Location / access

• Record pane ID and surface numbering (#1-#4; laminate-internal). If the frit is on #2/#3 (IGU interior) or otherwise non-exposed, in-place correction is out of scope → CAT-5 by location (classification remains Co.05.02).

Mechanism cue (context)

• Particulate contamination on glass or screen, insufficient wet film, air entrapment/solvent pop, screen mesh anomalies, edge draw-down, or local adhesion loss at point seeds post-fire.

Assign CAT by visibility at acceptance geometry and count/density within critical sightlines. Depth values are apparent optical, not substrate relief.

• CAT-1 (Benign / non-relief): Few, very fine pinholes legible mainly at oblique/back-lit; SC-0 viewing face; cumulative affected area negligible.
• CAT-2 (Light): Scattered pinholes visible at standard distance in common lighting; SC-0; cumulative area ≤0.5% of the frit field.
• CAT-3 (Moderate): Clusters/bands or repeatable rows visible at standard distance affecting perceived uniformity >0.5% area or along critical sightlines/margins; SC-0.
• Reclassify when:
• Points accompanied by front-face pits/fused nodules → consider Th.01 Hot particle impingement.
• Loose paint on viewing face lifts on reveal → R.02.01 Paint overspray film (not frit voids).
• Opacity mottle without discrete points → Co.04.01 Mottle/Cloudiness.
• CAT-5 (by condition/location): Between-pane/inaccessible frit face or system constraints preclude in-place work → CAT-5.

CAT is appearance-based; acceptance is separate under VIS-A at 12/36/72 in. When on non-exposed faces, frit pinholes are typically producer/system-governed and outside in-place restoration scope.

• vs. Back-paint pinholes (Co.04.02): Both read as bright points, but system and location differ; confirm ceramic frit vs. organic back-paint and face.
• vs. Mineral peppering (Ch.03): Mineral systems show ring/run wetting geometry and may yield SC-1/2; Co.05.02 is ringless and SC-0 at the viewing face.
• vs. Surface abrasion pitting (M/Th): True surface pits exhibit SC-1/2 and micro-crater morphology at the viewing face; frit pinholes remain planar behind glass.
• vs. AR/low-E pinholes (Co.01.03): Functional low-E/AR pinholes alter interference color on vision coatings; frit pinholes occur within opaque/semi-opaque ceramic artwork.

• Photo set (VIS): 12 / 36 / 72 in, normal + oblique; back-lit frames to reveal points; macro/raking frames confirming smooth viewing surface.
• System ID. Confirm frit face, pattern spec, lot/date; obtain shop drawings/submittals if available.
• MSRT (viewing face). Record SC-0.
• Lot/replication check. Survey adjacent units for coordinate repetition (supports producer-intrinsic origin).
• Forms: Pane ID; surface numbering & worked-surface status; reveal status; lighting/time; geometry checklist; photos attached.
• Acceptance split: Post-restoration acceptance per VIS-A §6; classification ≠ acceptance.

• Co.05.02 Pinholes / Voids (Ceramic Frit) - Discrete clear points within fired frit on surface #___ (frit face confirmed); MSRT (viewing face): SC-0; visible at [12/36/72 in] under VIS geometry (back-lit/specular). Morphology: point voids, no chip-flank grooves/pits at viewing face. Classification: CAT-[1/2/3] by visibility/density; CAT-5 if between-pane/inaccessible. Forms + photo set attached; acceptance per VIS-A §6.