Buffing

At 2,000 rpm, a 150 mm buff has 15.71 m/s peripheral speed. A worn 120 mm buff at the same rpm gives 12.57 m/s, a 20% decrease. Record diameter with rpm and check wheel, mounting and machine ratings before changing speed.

Process and terminology

A rotating buff can carry applied compound or embedded abrasive. Specify roughness, gloss, size and suitability for later coating separately.

Norton describes conventional buffing with stick or liquid compound and distinguishes cut buffing, which removes preparation scratches, from color buffing, which develops luster. Here “color” means the appearance stage, not applying a colored coating. Its account includes both material removal and redistribution at the surface. Norton process description, July 20, 2023

“Polishing” and “buffing” are not used consistently across suppliers. Foredom's guide, for example, calls coarse buffing the cutting-down stage and polishing the final luster stage. Specify the tooling, sequence and required result rather than relying on a supposedly universal distinction between the two words. Foredom guide, PDF page 3

Wheel and compound selection

A useful process definition combines workpiece material/condition, initial surface, buff construction, compound, equipment and target result. Wheel stiffness, stitching, shape and access affect how the tool contacts the work. Foredom contrasts softer cotton for delicate work with stiffer cotton/hard felt for cutting; these are supplier examples. Foredom wheel selection

Foredom lists Emery A-4001 for cutting hard metals, excluding gold, silver and plated items, and Red Rouge A-4004 for final coloring of specified precious metals. Product identifiers and application restrictions are more reliable than assuming compound colors mean the same thing across brands. Foredom compound descriptions, PDF page 2

For a different process variant, Norton's Fixed Abrasive Buff (FAB) uses pre-adhered abrasive on nonwoven backing. The cited 2023 article positions the introduced products mainly for cut buffing and says they are generally unsuitable for final color buffing. Do not transfer a conventional cotton-wheel recipe or a claimed finish directly to that product family. Norton FAB applicability

Keep stages and media identifiable. Foredom recommends separate wheels for different compounds to avoid contamination and scratches. Preserve wheel identity and workpiece cleaning between stages in a repeatable process. Foredom compound segregation

Preparation, heat and geometry

A final shine does not prove that deep preparation scratches were removed or that geometry remains acceptable. Define the incoming condition and the defects each stage must remove. Qualify the sequence on representative material and geometry before treating a cosmetic sample as evidence for production parts.

MERARD identifies rotation speed, applied pressure and time as interacting variables, alongside compound and mop selection. It warns that surface heating can change the surface condition, including waviness or orange peel. Its examples are application guidance, not a universal speed table for all tools carrying the same process name. MERARD polishing-speed guidance

Preserve critical edges, sealing faces, thin walls, engraving and dimensional datums. Identify regions that must remain untouched and the permissible edge condition. Stock removal needed to eliminate a scratch may conflict with the remaining dimensional allowance. Do not approve further buffing merely because it improves reflection.

For plated parts, consider the coating as well as the substrate: the allowed removal and compatible compound must be established for the actual coating system. A product suitable for bare steel does not automatically suit a thin plated surface. Avoid inferring a universal removal rate from wheel speed or processing time.

Original surface-speed calculation

For an ideal circular wheel, peripheral speed is:

v = π × D × N / 60, with diameter D in metres and speed N in revolutions per minute.

For an illustrative 150 mm wheel at 2,000 rpm:

v = π × 0.150 × 2,000 / 60 ≈ 15.71 m/s.

At the same rpm, a worn 120 mm diameter gives:

v = π × 0.120 × 2,000 / 60 ≈ 12.57 m/s.

The speed change is geometric. Check wheel and machine limits before any rpm adjustment.

A wear-control record should therefore preserve wheel diameter as well as rpm where peripheral speed matters. Pressure, compound delivery and contact geometry remain separate variables, so equal peripheral speed alone does not establish equal finishing behavior.

Inspection and downstream cleanliness

Agree what “bright,” “mirror” or “uniform” means for the job. Use approved appearance references and defined viewing conditions where cosmetic consistency matters. If functional roughness, profile, edge radius or dimensions are required, specify and measure those separately. A reflected image cannot substitute for a specified numerical surface-texture evaluation.

Inspect after the agreed cleaning stage. Norton identifies residual compound as a significant downstream-cleaning issue, particularly in crevices and surface details. Select cleaning compatible with the material and subsequent coating, bonding or service requirements; do not adopt a generic solvent or alkaline wash from a process label. Norton cleaning discussion

Retain representative geometry and the actual incoming finish when qualifying appearance and cleaning. A flat coupon may not represent access, residue retention or edge exposure on a recessed production component.

Equipment and worker controls

Use the manufacturer's instructions for the exact wheel and mounting. Foredom provides mounting-specific speed limits and warns about thrown workpieces, loose clothing and debris; do not generalize its ratings. Foredom safety recommendations, PDF page 1

For US general-industry applications, OSHA 29 CFR 1910.94(b) addresses grinding, polishing and buffing ventilation, including applicability and hood/exhaust requirements. Evaluate the actual material and equipment with the applicable workplace requirements. This article supplies no exhaust-system design, exposure assessment or protective-equipment selection. OSHA ventilation standard

Handoff and source versions

Preserve the part/revision, material/coating, incoming preparation, stage sequence, wheel/compound identifiers, diameter and speed, qualified contact conditions, protected features, cleaning method and separate appearance/dimensional acceptance criteria. Record changes that could alter the qualified result.

Foredom's actual PDF prints F-1234 10/20; Norton's article is dated July 20, 2023. MERARD displays 05.01.22, retained as printed rather than inferring its date convention. The cited OSHA page is the live regulatory text checked on the review date. The speed arithmetic and proposed handoff questions are original guidance.

Surface-finishing processes