Fengfan Aluminum Alloys / Aluminum Anodizing Chemicals Polishing Additive Liquid 126 ADD

Product Overview

A liquid additive for the sulfuric–phosphoric chemical polishing bath, dosed into the acid to govern how the bath cuts. The acids do the work of dissolving metal; the additive evens that attack out, so micro-peaks on the surface are smoothed away and the workpiece leaves the tank with a bright, mirror-like reflectivity instead of a flat grey etch. Its real value on the line is gloss uniformity — parts from the front and the back of a rack come out looking the same, which is what makes the finish usable as a base for aluminum anodizing.

The bath is not limited to aluminum. Pure aluminum and aluminum alloys are the main substrates, and stainless steel can be run in the same chemistry where a bright finish is wanted there too. Shops running an aluminum anodizing service use it ahead of dyeing and sealing; machining shops polish parts before sending them on; electrical and electronics manufacturers run housings and heat sinks through it.

Handling is straightforward. The additive is weighed into the acid bath, the bath is brought to its working temperature, and parts are immersed for the time the job needs. From there the line carries on as normal: rinse, then anodizing or a conversion coating.

Operating Data

Materials & Alloy Compatibility

• Pure aluminum — the easiest substrate to read: gloss comes up quickly and evenly, so it is the sensible starting point when a new bath is being set or an operator is being trained.
• Aluminum alloys — alloying elements change how the acid attack behaves from grade to grade, so the same bath can give a slightly different colour depth on two alloys. Run a panel from the actual lot before the production run.
• Stainless steel — the same dual-acid chemistry brightens stainless parts as well; treat the first run as a trial, because the base finish differs from aluminum.
• Before anodizing, not after — this is a pretreatment for anodized aluminum. Once the oxide has grown, the surface can no longer be levelled this way.
• Before conversion coatings — where parts go on to an alodine-type pretreatment, polishing first improves the smoothness the coating is applied to.
• Other metals — copper, steel and plated parts sit outside the intended scope; check with us before running them through a bath built for aluminum.

Polishing Step in the Anodizing Line

1. Strip the oils and polishing wax first — a bright polish over a contaminated surface simply locks the contamination under a smooth skin.
2. Rinse thoroughly. Carry-over water dilutes the acid bath and drags surfactant residues into it.
3. Charge the tank with sulfuric and phosphoric acid at the working ratio, then add the polishing additive at its dose. Bring the bath up to temperature before the first part goes in.
4. Immerse the work on racks or in a basket. Keep the immersion time identical for every load; that single discipline does more for batch-to-batch consistency than any other adjustment.
5. Rinse twice after the polish. The first rinse knocks down the bulk acid, the second stops the reaction before it can dull the surface.
6. Inspect under reflected light, then pass the parts to the next stage of the aluminum anodizing process — anodizing, dyeing, electrolytic colouring, sealing, or a conversion coating.

Decorative & Architectural Finishing

Architectural panels, façade elements, decorative hardware and interior trim are judged on appearance, and that judgement starts well before the aluminum anodizing tank. A part polished in this bath reflects light as a true surface rather than a scatter of small defects, so the finished panel reads as bright and even across its whole face instead of showing swirls and dull patches under a window.

Colour work benefits too. Dyed and electrolytically coloured parts take colour more evenly from a well-polished surface, and hairline scratches that would read as dark lines after colouring are gone before the dye goes on. That matters most on visible faces — handrails, window frames, appliance trims, nameplates, light fittings.

Clear finishes gain for a different reason. Where no dye is used the oxide itself is the finish, and everything the eye sees is the condition of the aluminum underneath, which is why bright clear work on anodized aluminum depends on what happens at the polishing stage.

Small shops working from an aluminum anodizing kit get the same result at bench scale: the bath behaves the same way in a small tank, and a handful of panels is enough to judge whether the finish suits the job.

High-Volume & Automatic Line Production

• Built for continuous operation — gloss stays uniform across a shift, which is what a line running automotive trim, electronic enclosure shells or heat sink components needs.
• Steady bath behaviour — the additive is consumed predictably, so the bath is topped up on a schedule instead of being corrected after parts start failing inspection.
• Fewer rejects downstream — a consistent polish takes one variable out of the aluminum anodizing service you are running, so colour and sealing problems can be traced to their real cause.
• Fits existing dosing arrangements — as with any plating chemicals line, the additive is fed by weight against bath volume, so it can be added by hand or through automated feed without changing the tank layout.
• Throughput without rework — stable gloss means parts do not go back through the polisher a second time, which is where most of the real cost of a polishing stage sits.
• Scales with the tank — the same working ratio applies whether the bath is a few hundred litres or a full production tank.

Trials, Labs & Small Workshop Baths

1. Cut three or four panels from the production lot — same alloy, same thickness. A trial only means something if the sample matches what will run later.
2. Prepare a small bath at the working acid ratio and add the polishing additive at its stated dose; a beaker on a hotplate is enough to see how the chemistry behaves.
3. Hold the temperature steady and vary only the immersion time between panels — time is the most useful variable to master in the aluminum anodizing process.
4. Compare the panels side by side under the same light and note where the surface starts to lose definition. That point is the ceiling of your working window.
5. Write the chosen time and temperature into the work instruction, then run it once more to confirm the result repeats.
6. Scale up: the same ratios apply whether the next step is an aluminum anodizing kit, a pilot bath or a full production line.

Packing & Storage

• Supply pack — 25 kg or 30 kg containers, sized so a mid-volume bath can be charged without splitting a drum.
• Storage temperature — keep the container between 5 °C and 35 °C.
• Storage humidity — 25% to 85%.
• Reseal after every draw — the additive is dosed by weight, and an open container takes up moisture between batches.
• Rotate stock — use the oldest container first, and check the batch label against the delivery note before charging a bath.
• Handle as a bath chemical — it goes into a hot acid bath, so normal chemical handling and protective equipment apply at the tank.

Ordering & Delivery

Gloss Control & Surface Condition

Keeping gloss even

Gloss in a dual-acid bath comes from three settings held together — acid ratio, temperature and immersion time — and a bath that drifts on any one of them sends out a rack of parts that do not match each other. Titrate on a fixed schedule and top the sulfuric and phosphoric acids back to 35%–45% and 50%–70%. Dissolved aluminum builds up as the bath works and quietly changes how the acid attacks the surface; extra additive will not put gloss back once the acid balance has moved, it only leaves an excess sitting in the tank. Read the finish on a coupon polished with every load, under the same light each time, because the eye adapts to a bright surface within seconds and will call a dull part bright. Immersion time is the lever with the narrowest safe band: brightness climbs fast in the first tens of seconds, then levels off, and past that plateau the acid starts dissolving the surface it has just smoothed and takes the shine back down to a matte etch. Find your own plateau by pulling panels at 20 seconds, 1 minute and 3 minutes. Temperature behaves the same way near the top of its range — at 100–110 °C the attack runs faster and the plateau arrives sooner, so a hot bath leaves less margin for a slow transfer between tank and rinse. Over-polishing shows up as shape rather than colour: edges rounded off, stamped lettering softened, punched holes opened up, thin sections dished. That is metal leaving the part and it cannot be polished back, so rack fine-detail work for the short end of the time range and inspect it first. Give parts room as well; two faces pressed together come out with a dull shadow that only appears after aluminum anodizing, and a water break left to dry on the surface reads as uneven gloss when the fault is in the rinse rather than the polish.

Surface condition limits

This bath levels at a microscopic scale. It removes the fine peaks left by turning, milling, fine grinding and brushing, and the directional lines of a grained finish soften as the surface comes down — the finer and more uniform those marks are, the closer the result comes to a mirror. It does not replace mechanical preparation. Chatter, step-over ridges, deep tool marks, weld beads and cast skin sit far below the reach of a bath meant to remove microns, and leaving a part in longer to chase them costs edge definition and dimensional tolerance long before the marks disappear. Brushed stock deserves its own note: the texture is deliberate, polishing reduces its contrast, and where the brush pass itself was uneven the grain can finish looking patchy. Where a brushed appearance is the specification, either set the finish after polishing or keep the polish cycle short and judge the outcome on an anodized panel rather than a bare one, since the oxide film changes how the grain reads. The practical test is one panel per surface condition — as-machined, as-brushed, as-received from the previous step — run through the same cycle together and compared on the finished part, which is the only point at which the difference becomes visible.

Use Scenarios

Where and how you plan to use this product should guide the specification you choose. Buyers usually tell us they are furnishing a home, fitting out a shop or studio, or preparing repeat orders for their own customers, and each of those situations puts different demands on materials, finish and packing. Let us know the setting, how often the item will be used, and whether it will be handled by staff or by end users, and we can point you to the configuration that meets those requirements most closely. If your scenario is less common — regular outdoor exposure, heavy daily handling, or a tight installation space — share the details before ordering so suitability is confirmed rather than assumed.

Technical Support & Model Matching

Choosing the right match is where most sourcing decisions stall. As a trading supplier, we keep one point of contact from first enquiry to after-sales: tell us what you are making and the conditions you work under, and we shortlist the closest matches from our supplier network, compare specifications and arrange samples before you commit to a bulk order. If something does not behave as expected, we work with the supplying partner on the cause and a practical fix, and stay with the case until it is settled. Email, WeChat or WhatsApp enquiries get a reply within 24 hours.

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