DSS-Th.01.02 — Grinder Spark Embed (ferrous peppering)

Grinder spark embed presents as a fine “peppered” field of ferrous particles ejected from metal grinding/cutting that impact, fuse, and/or oxidize on the glass. Some particles remain proud/fused; others detach leaving micro-pits. Classification is appearance-only per VIS; methodology is out of scope. Inspect under VIS lighting/geometry after Non-Invasive Reveal; record surface numbering and worked-surface status on Forms:

Broad fine peppering oriented toward the grinding work area; individual particles appear dark/rust-colored specks; where detached, bright micro-craters show in raking light.

Often more uniform and finer than welding slag spatter; can extend across panels aligned with airflow or gravity.

May include light rust halos around retained ferrous specks.

Surface-catch class (MSRT)

On retained specks and micro-pits, a single, light, non-marring pass typically yields SC-1 (slight) to SC-2 (clear) on representative features. Do not abrade; one pass only. Use a polymer stylus if a coating is suspected. MSRT supports classification only.

Visual signature

High-density field of minute, discrete points; many with tiny bright pit rims in raking light; lacks long continuous tracks of linear scoring.

Some specks show oxidized (brown) tonality; pits read as sparkly rims under oblique.

Viewing / lighting

Evaluate clean & dry at 12 / 36 / 72 in, normal incidence and oblique sweep (~60°-120°) with raking light per VIS.

Location / access

Record pane ID and surface numbering (#1-#4; laminate-internal). If fixed parallax indicates between-pane, record CAT-5 by location (out of in-place scope).

Mechanism cue (context)

Frequently associated with construction grinding/cutting near exposed glass (rebar, studs, railings), producing nearly molten shards that embed in the surface.

Assign CAT by appearance + MSRT + morphology (three-part cueing). Depth bands below are indicative only-numeric measurement not required for field classification.

CAT-2 (Light): Sparse to light peppering, mostly SC-1 on select points; visible mainly at raking and close/standard view; limited field impact. Indicative pit depth: ~10-40 μm; pit diameter commonly ≤0.2 mm.

CAT-3 (Moderate): Noticeable cluster fields with frequent SC-2 micro-pits and bright rims; clearly visible at standard distance; occasional retained specks. Indicative pit depth: ~40-120 μm.

CAT-4 (Severe): Dense, widespread peppering; many clear-catch pits and intermittent fused nodules; readily apparent at standard and wide-field views. Indicative pit depth: ~120-300 μm+.

CAT-5 (by location/condition): Between-pane cues, active cracks/pane instability, or confirmed functional-coating loss on the surface to be worked → CAT-5 (non-repairable/out of in-place scope).

CAT is appearance-based; acceptance is separate and governed by VIS §6 at 12/36/72 in under defined conditions.

vs. Welding slag spatter (Th.01.01): Slag fields tend to include larger fused nodules and rougher craters; grinder pepper is finer, more uniform and more “dust-like.”

vs. Linear scoring (M.01): Scoring forms continuous lines with abrasive chip-flank sparkle; peppering is discrete points without run-length.

vs. Sand abrasion (E.02.01): Eolian abrasion appears as directional matte fields (non-discrete) and may show modeled micro-texture rather than discrete pits.

vs. Coating anomalies (Co.01/Co.03): Coating rub/patchiness shows sheen/color shift without pit rims; coating anomalies on the worked coated surface are not permitted at acceptance.

Photo set (VIS): 12 / 36 / 72 in; normal + oblique; include raking macros that resolve pit rims/retained specks and at least one context frame showing proximity to grinding operations. Record distance/angle in-frame.

MSRT result: One light, non-marring pass on a representative spot; record SC class (SC-1/SC-2 as observed). Prefer polymer stylus if a coating is suspected.

Forms: Pane ID; product family & surface numbering; worked surface Y/N; functional coating present on worked surface? (Y/N/Unknown); reveal status; lighting/time; geometry checklist; photos attached.

Acceptance split: Post-restoration acceptance per VIS §6 at 12/36/72 in; classification ≠ acceptance. Coated-face appearance rules apply per VIS §6.2.e.

Th.01.02 Grinder Spark Embed (Ferrous Peppering) - Fine discrete pepper field with retained specks / micro-pits on surface #___ documented at 12/36/72 in, normal + oblique with raking; MSRT = SC-[1/2] on representative points. Morphology shows discrete pits with bright rims; no continuous scoring. Classification: CAT-[2/3/4] by density and relief; CAT-5 if between-pane, integrity cues, or coating-side loss on the surface to be worked. Forms + photo set completed; acceptance per VIS §6 (separate).