A robotics manufacturer in Bordeaux, France working in robotics and automation has an aluminium joint housing whose bearing bore, shoulder and dowel holes must survive deburring intact. SurfacePolish supplies finishing machines, media and compounds across borders and runs a free sample trial: representative parts travel to the factory in Xiamen and come back with observations and a proposed media, compound and cycle direction for the buyer's own review. This brief is written for a buyer in Bordeaux working on robotics and automation; it describes equipment, media and a scoped sample review, not a local polishing service.
Which surfaces on the part are functional, such as bearing bores, dowel holes, seal lands, ground mounting faces and threads, and which are only cosmetic?
What is the size and mass spread inside one part family, and does one machine have to cover both a heavy casting and a small gripper jaw?
What is the smallest hole, slot, keyway or cross-drilling the charge must not enter or plug, and how will a lodged medium be detected and removed?
Begin with a marked-up drawing rather than a part family name. On a robot joint housing, an actuator body or a gripper base plate, the surfaces that carry function form a short and severe list: bearing bores and their shoulders, dowel and pin holes that set position, seal grooves, ground mounting lands, clamp faces and threaded holes. Every one of those needs a decision before a medium is chosen, whether it is masked, plugged, finished to a stated limit or deliberately left as machined. The cosmetic list is usually longer, covering external webs, covers, ribs and visible faces that only have to look even. Separating the two lists prevents the most common error in this work, which is selecting a charge by part size and then discovering that it has been working a bearing seat that had to stay round.
Disc finishing machines and centrifugal barrel machines deliver far more energy per unit of time than a bowl. A disc machine works the gap between rotating discs, which suits batches of small robust parts such as gripper jaws, mounting blocks and machined brackets where a consistent edge break is wanted quickly. Centrifugal barrel finishing multiplies the effective gravity acting on the charge, so cycles shorten and contact pressure rises sharply, which suits small precise parts and can round a thin section or deform a soft aluminium wall within a short over-run. Both routes depend on charge weight, speed, fill level and stop time being held to a record. They are a poor match for thin-walled housings, long beams and any part whose functional edge or bore lip must keep a tight radius.
| Machine route | Where it fits | What it will not do |
|---|---|---|
| Dry polishing machine and dryer | Removing residual moisture after a wet cycle and reducing water spotting on aluminium and stainless surfaces with pockets and threads | A finishing step only; a dry part can still carry compound film, fines and media dust, so it is not a cleanliness release |
| Vibratory finishing machine, bowl type | General deburring and refinement of machined housings, plates and brackets that fit and can tumble without racking, with easy mid-cycle inspection | Continuous part-on-part contact and no access to deep internal passages; thin plates and finished mounting faces need separation |
| Tub vibrator | Long parts such as linear-axis beams, manifolds and welded frames that cannot rotate in a bowl | Lower energy per unit area so heavy burrs take longer, and large tubs need floor space and a reliable part support method |
| Grinding finishing machine | Taking off a heavy machining burr, dross or a defined stock layer before a refinement pass on robust steel and stainless work | High removal energy cuts functional edges fast and demands a tighter assessment of what may be removed and how much |
The material family of the media sets how much energy reaches the part. Plastic media is lighter and is the conservative choice for aluminium housings, thin cover plates and machined faces that must not be peened, at the cost of a slower cut and a shorter media life. Ceramic cuts harder and holds its shape longer, which suits removing a machining burr from steel and stainless parts and blending edges, but it marks soft aluminium and rounds functional edges faster. Steel media burnishes to a bright appearance and works well on stainless, and it is the wrong starting point for aluminium because it transfers iron and can leave spotting that appears later. Wear behaviour differs across all three: ceramic shrinks and generates sludge, plastic deforms and floats differently, and steel can fracture into slivers.

| Media | Best fit | Watch out for |
|---|---|---|
| Fine ceramic or porcelain shapes in a small size class | Edge blending and surface refinement after a cutting stage, and reaching tighter external geometry on machined housings and brackets | Small sizes enter and retain in tapped holes and fine slots, and media wear shrinks the charge so the finish drifts over its life |
| Heavy-cut ceramic, angle-cut triangles in a coarse size class | Removing a substantial milled or turned burr from open external edges and pockets on steel and stainless automation parts before a refinement stage | Cuts functional edges and corners aggressively, leaves a coarse surface on aluminium, and lodges in slots whose width approaches the media section |
| Dry media such as walnut shell and corn cob | Drying assistance and light surface polish after a wet cycle, particularly on parts with pockets and threads that must not stay wet | Does not deburr or refine metal significantly, generates dust, and must not be treated as a cleanliness step |
| Magnetic finishing pins and fine magnetic media | Small precise items such as spools, orifice plates, small valve parts and fine slot arrays where tumbling media cannot reach the feature | Limited working envelope, pins lodge in the same fine features they are chosen to reach, and the surface signature differs from tumbling |
Contamination failures are quiet and are often attributed to the wrong operation. Aluminium fines left in a machine, a charge or a sump transfer onto stainless parts as a grey smear in the next batch. Iron from steel media, from a machine that has held carbon steel or from a tool used on both transfers to stainless and shows as pinpoint rust spots that appear hours or days later. Hard or high-chloride rinse water and slow drying leave mineral rings and haze on aluminium. A compound that is too aggressive darkens aluminium or attacks a freshly cut edge. The controls are procedural: segregate or dedicate media by material family, define and record the changeover, control rinse water and drying, and inspect after a defined dwell time rather than immediately. Left unchecked, these defects surface after the parts have moved on.
| Failure mode | Likely cause | How to catch it |
|---|---|---|
| Compound film, smut or tenacious residue left on a face or in a bore | A film-forming or silicate-bearing compound, insufficient rinse volume, or drying a part before it is genuinely clean | Magnify the suspect surface, wipe a defined area with solvent against a clean reference, and confirm with the buyer's own cleanliness method |
| Grey aluminium smear transferred onto stainless parts in a shared batch | Aluminium fines retained in media, compound or the machine sump after an aluminium lot, with no purge before the stainless lot | Check stainless surfaces under angled light for a dull grey film, review the changeover record, and inspect the charge and sump for retained fines |
| Impact marks, dents or a peened, rippled appearance on a visible aluminium face | Charge mass or load ratio too high, light parts left loose among heavy neighbours, or a soft alloy run on a route chosen for steel parts | Look for repeating mark patterns under angled light, compare a part run loose with the same part compartmentalised, and review the batch mix and load recorded for the lot |
| Colour change or darkening on an aluminium face after the cycle | Compound chemistry unsuitable for aluminium, no effective corrosion inhibitor, or a delay between finishing and drying | Compare the finished face with an unprocessed coupon of the same alloy under the agreed light, and review the compound product, dose and rinse sequence for the lot |
Bordeaux combines an Atlantic port economy with an aerospace and defence industrial base: the Port de Bordeaux operates seven specialised terminals along the Gironde estuary and Garonne, receives close to a thousand vessels a year, and states that the industrial-port complex accounts for 8 620 jobs, with a stated strategic aim of building a new industrial-port model around energy transition. INSEE counted 14 432 establishments in the commune at the end of 2024, 3,2 % in industry, and 211 556 jobs at the place of work in 2023. The wider Gironde industrial base includes aeronautics and defence (Dassault Aviation, Thales and ArianeGroup sites around Merignac, Saint-Medard-en-Jalles and Le Haillan), naval and yacht refit activity in the port, and food and wine-related manufacturing.
The nearest part of that base to this brief is marine: The Port de Bordeaux runs a dedicated maintenance and ship-repair line covering refit, retrofit, maintenance and wintering, supported by its own port workshops and quays.
Aerostructures, space hardware and defence equipment built in the Bordeaux area need controlled edge quality on machined and formed parts, deburring of fluid and pneumatic components, and surface preparation for bonding and coating, all with the traceability that EN 9100 work demands. The port's naval refit and yacht activity adds a second, very different requirement - large-surface preparation, weld dressing and finish on hulls and superstructures in a marine corrosion environment. Food and wine equipment in the region adds stainless fabrication where surface roughness and residue-free cleaning matter hygienically.
A Bordeaux buyer should settle whether the finishing operation supports a bonded or coated surface, because in that case surface chemistry and cleanliness, not just roughness, decide whether the process is acceptable - and those parameters must be specified before a machine or media is selected.
Freight context: Port de Bordeaux (7 terminals: Bassens, Bacalan, Le Verdon, Blaye, Pauillac, Ambares, Bordeaux), Bordeaux-Merignac Airport. The port operates 24 hours a day, 365 days a year and states that its seven specialised terminals along the Gironde and Garonne receive close to a thousand vessels a year, with the industrial-port complex supporting 8 620 jobs. For equipment imports this means the machine can be landed directly on the estuary at Bassens or Verdon and moved by road, with Bordeaux-Merignac handling urgent parts and media samples.
The working language of French industrial procurement is French: tenders, drawings, inspection plans and technical dossiers are normally issued and answered in French, and quotations that omit French documentation slow down qualification. Buyers qualify a machine against a written specification and expect traceable material certificates, machine safety documentation and, where applicable, a CE declaration of conformity and a risk assessment; acceptance is often staged (documentary review, factory acceptance test, then commissioning). Payment and documentation norms are conventional EU practice: euro invoicing, SEPA or SWIFT bank transfer, Incoterms agreed in writing, and customs paperwork (commercial invoice, packing list, transport document, proof of origin where a preference is claimed) prepared for the declarant or customs representative. Because customs and tax authorisations are handled jointly through SOPRANO, non-EU sellers are normally advised to sell to an established French/EU importing entity rather than to act as importer of record themselves.
For imports from outside the EU the declarant must file a customs declaration whose form and content are fixed by the Union Customs Code and its implementing provisions; French Customs identifies classification, origin and value as the three fundamental notions and makes the common/national tariff consultable via RITA. The customs authority is the Direction generale des douanes et droits indirects (DGDDI), which also runs the Info Douane Service for formalities questions. Buyers should expect to need an EORI number and an EU VAT treatment, because customs and tax authorisations are handled together (SOPRANO). For machinery, the CE marking and the applicable EU product-safety directives are the compliance gate items to settle before shipment, and the French market surveillance authority is the DGCCRF; the tariff rate itself must be confirmed per HS code in RITA or the EU Access2Markets tariff tool, since it varies by machine type.
SurfacePolish supplies from Xiamen, China. The buyer's own destination rules, conformity marking, tariff classification and documentation responsibilities stay with the buyer; confirm them against the authorities named above before ordering.
Roughness is only comparable when the measurement conditions are fixed. State the location by distance from a reference feature, the traverse direction relative to the machining or media marks, the cut-off and the evaluation length, then use the same conditions for the first article and for production checks. A reading taken along a bore axis and one taken around its circumference describe different surfaces. Curvature limits how a skid or shoe sits on the work, particularly in a small bore or on a narrow land, and a poorly seated pickup is not evidence. Take readings at several stations, because the ends of a part and the middle of a part often differ. Where visual appearance is what the customer sees, pair the number with a physical reference viewed at an agreed distance, since a surface can measure inside a band and still look wrong.
A trial can only be read against a documented starting point, so record the incoming condition before shipping. Photograph each critical feature at a fixed scale, measure roughness at marked locations with the instrument, cut-off and direction noted, check edge condition with a radius gauge or comparator, and record mass and critical dimensions. Note the as-received burr, existing scratches, cutting oil or coolant and the condition of any tapped hole. Keep one piece unprocessed as the baseline. When the parts come back, compare them against those records rather than against memory or photographs taken on a different day under different light. That pairing is also how the buyer distinguishes a change produced by the process from a feature the material already carried.



Size the medium well below the smallest opening the charge could enter, and treat every passage as a retrieval point rather than assuming it stays clear. Map the tightest tapped hole, keyway or cross-drilling first, then choose a size class against that geometry instead of an average part. Add a defined check such as a pin or thread gauge on holes, a borescope at an agreed angle and a rinse collected through a filter. For a trial, send the part with the smallest opening so the media choice is tested on the real feature. SurfacePolish reports what was observed on the tested parts; the release decision remains with your own quality function in France.
Change one variable at a time. Hold the machine, load, compound, cycle time and part mix constant and change only the medium. Use parts from the same production lot so the only difference is the variable under test. Label the pieces before they run and have the returned parts judged in one session, under the same light and at the same marked measurement points, rather than one at a time. Where several people judge appearance, ask each to rank the pieces before discussion. Where a cut stage is followed by a refinement stage, score the stages separately, because a good final result can hide an unremoved burr or an over-coarse first stage.
A trial shows what a given machine, charge and setting did to the parts tested, which is useful evidence but not a sizing study. Machine size depends on the largest envelope and mass in the family, the smallest part that must meet the same appearance, the load ratio you intend to run, and how many stages the part needs. Those are planning questions that belong in a line-concept discussion alongside the trial result. A part tested on a small machine may behave differently in a larger chamber, and a part run in a full production load may come out differently from one run in a light trial batch. Record both the settings and the load.
Use Bordeaux, France as the destination on the enquiry and state whether the deliverable is equipment, media and compound, a representative sample review or a line concept. A destination does not imply local stock, a local service point or a local delivery time.
A Bordeaux buyer would reference ISO/NF EN surface-texture standards for finish and EN 9100 for aerospace and defence work, plus customer specifications for bonding, sealing and cleanliness; ISO 9001 is the general baseline and marine work is governed by classification-society and owner requirements on top. Material conformity certificates and process traceability are standard expectations in the aerospace and naval supply chains here.
Sources were retrieved on 2026-09-29 and describe the local industrial and trade context only. They do not evidence any SurfacePolish project, shipment, installation or service in Bordeaux.
The buyer needs the milled edges broken and the external faces evened out without touching the bearing bore or closing a dowel hole.
Send the material, dimensions, approximate weight, batch quantity, the incoming condition and photographs of the difficult features. Mark which features must not be contacted by media and state how the result will be inspected. This form carries source reference PSEO-0580; quote it if you prefer an additional manual reference.
Open the SurfacePolish enquiry form Email a prepared enquiry
No price, lead time, certification or result is promised here. Confirm whether a sample trial is available for the specific part and what the trial can and cannot show.
Page PSEO-0580 · revised 2026-09-29 · cross-border equipment, media and scoped sample review. City context is sourced and cited above.
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