HARD
MASKING.

What hard masking actually means

Hard masking refers to physical, reusable, rigid or semi-rigid protective components — silicone plugs, custom fixtures, and heavy-duty die-cuts — used to isolate critical surfaces during aggressive coating preparation and high-temperature finishing. Unlike tape or paper, these components are engineered to withstand extreme heat, harsh chemicals, and physical abrasion without degrading, lifting, or leaving adhesive residue behind. The right masking is what makes precision coating possible — it defines the boundary between protected and coated surface with zero tolerance for drift.

1. Molded silicone caps and plugs

Molded silicone is the industry standard for protecting fasteners, cylindrical ports, and smooth shafts. Its high-temperature threshold — up to 600°F / 315°C — and excellent chemical resistance make it the go-to choice where tape and foam would fail on first contact with the blast cabinet or oven.

• Tapered plugs — Used to seal threaded holes, blind holes, and pipe ends. Pull-plugs with an elongated tail handle allow fast installation and clean extraction through through-holes without marring threads.
• Masking caps — Designed to stretch tightly over exposed studs, bolts, and pins, holding position under abrasive blast pressure without shifting or deforming.
• Multi-flange and ribbed designs — Engineered for variable hole diameters or operations requiring a structural grip strong enough to resist high-pressure abrasive blasting. The ribbed profile locks against the bore wall rather than relying on friction alone.

2. Custom engineered fixtures and hard tooling

For complex geometries or high-volume production lines, off-the-shelf plugs don't provide adequate coverage or process efficiency. Custom hard tooling eliminates per-cycle setup time and ensures repeatable masking geometry run after run.

• CNC-machined shrouds — Mating components machined from Delrin or aluminum that completely isolate complex external dimensions, flanges, and precision-machined surfaces from prep work. Toleranced to the part drawing, not approximated.
• Threaded metal plugs with rubber overmolds — A rigid metal thread provides precise, torque-able engagement while a silicone rubber perimeter seals the boundary, ensuring complete exclusion of blast media, chemicals, and powder overspray regardless of port condition.

Why it matters to your coating result

A coating is only as precise as the masking behind it. Overspray onto bearing surfaces, thread flanks, or mating faces causes fit failures, rework, and rejected parts. Hard masking components sharply reduce that risk by holding a defined, repeatable boundary through every stage — media blast, chemical conversion, spray application, and thermal cure. When your engineering drawing calls out specific keep-out zones, we take that seriously at the masking stage, not as an afterthought at inspection.