Every part that leaves our shop passes through the same disciplined sequence: inspection, mechanical preparation, graded abrasive refinement, mirror polishing, passivation, and final QA. No shortcuts, no surprises — just repeatable results our clients can spec into their assemblies.
A typical job takes between 36 and 96 hours depending on alloy, geometry, and target finish. Each stage is documented on the traveller that accompanies the part from receiving to shipping.
Every part is photographed, measured, and tagged with a unique job number on arrival. We verify alloy with a portable XRF analyzer, check critical dimensions against the customer's print, and flag any existing defects before work begins — so there's no ambiguity about baseline condition.
Parts are ultrasonically cleaned in an alkaline bath at 60°C to remove cutting oils, shop soils, and oxidation. We then mask threads, bores, and datum features with custom-fit plugs and high-temperature tape so finishes stay exactly where they're supposed to.
For cast or fabricated parts, we start with coated abrasive belts to remove mill scale, weld discoloration, and deep scratches. Operators follow a documented scratch pattern sequence — typically 60 → 120 → 180 — until the surface is uniform and ready for refinement.
Sanding discs and surface conditioning belts refine the scratch pattern in stages: 240, 320, 400, 600. This is where most of the visible "depth" of the finish is established. We inspect under a 4× lighted magnifier between each stage to confirm scratch uniformity before moving forward.
For mirror finishes, we transition to sisal and stitched cotton buffs charged with tripoli compound, working the part in overlapping passes to eliminate all visible scratch lines. This stage is where experienced operators earn their keep — hand contact, pressure, and buff speed all matter.
The cut-and-color stage. Loose cotton buffs loaded with fine green rouge produce the deep, distortion-free reflectivity our customers specify. We polish in multiple directions and verify the result with a gloss meter reading before moving the part to cleaning.
Stainless parts get a nitric or citric acid passivation bath to restore the chromium oxide layer. Everything — stainless, aluminum, brass — is ultrasonically cleaned, hot-air dried, and protected with a light oil or VCI film. A final QA pass closes the traveller.
We invest in production-grade equipment because repeatable finishes are impossible with under-spec tooling. Here's what's in our shop today.
| Equipment | Use | Capacity |
|---|---|---|
| Timesaver 1350WD-HD Wet/Dry Belt Sander | Pre-finishing, scale removal, weld cleanup | 52″ wide · 1350 series |
| Acme Flatmaster 80 Belt Polisher | Flat sheet, plate, and panel finishing | 80″ wide · 4 heads |
| Bullard Abrasive Tumbling Vats | Bulk finishing of small parts, deburring | 3 × 8 cu ft |
| Industrial Buffing Lathes (5 HP) | Cut & color, mirror polish, intricate geometry | 12 stations |
| Ultrasonic Cleaning Tanks | Degreasing, post-polish cleaning, passivation | 4 × 60-gallon |
| Byko-Spectra Gloss Meter | QA verification of specular finish (GU @ 60°) | 0–2000 GU |
| Handheld XRF Analyzer (Niton XL5) | Alloy verification, PMI on incoming stock | Mg–U elemental range |
Our QA system is built to be auditable. Every traveller records time stamps, operator initials, materials used, and inspection notes — so if a customer asks how a part was finished, we can produce the answer in seconds.
Before work starts, we confirm finish callouts in writing — Ra values, gloss units, sample approvals, or visual standards. No job moves forward without a documented "done looks like this" reference the customer has signed off on.
We work to ASTM A967 (passivation), ASTM B912 (passivation of stainless), ASTM A380 (cleaning/descaling), and SPI #1–#5 molding finishes for plastic polishing. If your print calls it out, we already know how to measure it.
Gloss meter readings, surface profile measurements, and visual comparison panels are recorded at QA. We don't ship a mirror finish that hasn't been verified with an instrument — a 200 GU reading is the typical floor for our mirror-grade work.
Every lot of abrasive, buffing compound, and chemistry is logged with manufacturer, batch, and date. If a customer ever needs a Certificate of Conformance covering finishing consumables, we can produce it from the same traveller that tracked the part.
First-article parts for new geometries, alloys, or finish callouts are always run as a paid sample. We finish, photograph, gloss-meter, and ship the sample for approval before committing to production quantities — no surprises at 80% completion.
If a defect is found at any stage, the part is tagged, photographed, and quarantined. We notify the customer before any rework begins, with a written disposition: rework, scrap-with-credit, or customer-call. Nothing is hidden, nothing is buried.
Send us your drawing, a sample, or just a description of what you need. We'll review the geometry, recommend a finish sequence, and quote a realistic lead time — usually within one business day.