Where It Fits
Most of the work that runs through this bath is general hardware: fasteners, brackets, hinges, wire forms, stamped components, garden and construction fittings and small castings that leave the plating line needing a colored, corrosion-resistant surface. In practice it is used by job shops running acid zinc plating chemicals on rack lines, and by in-house finishing departments that plate their own parts and want the color without a separate paint or lacquer operation. It also suits plants moving a part away from a hexavalent chromium passivate and wanting to keep a reddish tone on the shelf. The bath is deliberately narrow in what it does: it decorates and protects an existing zinc layer, it does not deposit anything, and it is not the right chemistry for an alloy deposit. If a part is new to your line, send the substrate, the zinc thickness and the corrosion requirement, and we will advise on the bath and the working conditions for it.
Ordering & Delivery
- Order size. Quantities vary by chemical and are confirmed with our sales team for each order, so tell us the pack you want and the volume you expect to use.
- Payment. 100% T/T in advance.
- Lead time. 2 weeks.
- Packing. 10 kg/box, 25 kg or 50 kg/bag, 20 kg/25 kg/30 kg/200 kg/drum, and 1000 kg/IBC drum. Pick the pack that matches your tank size and how you handle chemicals on site.
- Shipping. Per the terms agreed in the current contract.
- Documentation. An inspection certificate is issued after delivery, stating the batch number and the warranty period.
- Ordering with the rest of the line. Most customers take this passivator alongside the acid zinc plating chemicals they already buy, so it can travel on the same order and the same shipment.
- Tell us what else runs in the shop. If your line also runs zinc-nickel plating, mention it at enquiry; that alloy takes a different passivator and we would rather quote the right one.
- Trial before scale. If you have not run this chemistry before, ask your sales contact about a trial quantity so the bath can be checked on your own parts first.
Chemistry in the Same Range
- Zinc plating brighteners. SZ-30B for sulfate zinc plating, ZN 50 bright alkaline zinc for rack and barrel work, and ZN-500 for cyanide-free alkaline zinc.
- Aluminium anodizing. Phoenix EB 204A-204B divalent tin salt electrolytic coloring additive, plus the Phoenix Seal 149-L middle-temperature sealing agent and the 149-T medium-temperature sealing agent.
- Copper plating. FI-970 bright acid copper process for high deposit brightness.
- Surface protection. FF-4219 nano-protective for wood, stone and concrete, and FF-116 chrome mist inhibitor.
- Bath purification. Nickel Purify P3.
Post-Passivation Sealing
- Seal when the drawing asks for more than the film alone gives. Once the zinc is passivated to the reddish tone, whether it came from acid zinc plating chemicals or an alkaline cyanide-free line, a chrome-free sealer is the usual way to push the neutral salt spray result beyond the more than 96 hours the passivation layer delivers on its own. This is the route shops providing metal plating services take when the end customer specifies a longer test than the passivator can carry, rather than turning the job down.
- Choose the sealer by what the part needs next. PN-6 is a water-soluble chrome-free sealant for immersion or spray and is the general choice for extending salt spray protection. PN-7 is a chrome-free zinc sealing agent that forms a transparent organic film, adds surface hardness and scratch resistance, and is the better fit when the passivated surface will be handled or packed.
- Put sealing after the passivation rinse, before the final dry. The part leaves the passivator, gets its cool-water and hot deionized-water rinse, then goes through the sealer bath and straight to drying. Sealing a part that still carries passivator drag-out, acid or zinc salts gives a patchy film and an unreliable test result.
- Run PN-6 at 15–50% in room-temperature water. The concentration sets the film thickness: stronger baths leave a heavier layer. Keep the make-up water above pH 7 because the sealant flocculates under acidic conditions, dry at about 70 °C, and use a stainless steel, plastic or plastic-lined tank. PN-6 is not intended for barrel-plating automatic lines because it can block the drum perforations.
- Run PN-7 at 5–10% for a short dip. Immersion time is 5–15 seconds at room temperature, pH 8–9, with drying at 60–80 °C. The same pH rule applies to the water used for make-up. In barrel work, use a separator so the parts do not sit in a pool of sealant.
- Check what the sealer does to the reddish tone. PN-7 generally leaves the original passivation color in place because its film is transparent. PN-6 usually leaves the plated surface silver after sealing. If the red appearance is part of the specification, test the sealer on a sample of your own part before the whole batch goes through.
- Treat the salt spray gain as a system result, not a fixed addition. PN-6 is documented to improve the neutral salt spray protection of a passivated surface by 0.2–0.5 times the film's own result. Your hours will still depend on zinc thickness, the plating process behind the deposit, rinse quality and how the test is run, so re-test the sealed part rather than adding hours on paper.
- Do not use sealing to rescue a weak zinc layer. A sealer builds on a sound passivation film; it cannot make a thin, porous or poorly rinsed zinc deposit pass a test it would otherwise fail. If the unsealed part is already marginal, correct the zinc thickness or the passivation bath first, then seal.
Eco-Friendly Composition for Global Compliance
TR-150 is formulated without hexavalent chromium or oxidizers, which places it in line with RoHS and REACH restrictions on those substances. That matters if your customers or export markets ask for documented compliance, and it lets you work toward sustainability targets without changing the finish you already produce. Confirm the exact documentation your market requires with our team before ordering.
Integration into Existing Zinc Plating Lines
TR-150 is built to drop into a standard zinc plating workflow rather than demand a rebuild of the line. The process parameters stay stable from run to run, so bringing it on stream causes minimal disruption to existing operations and results remain highly reproducible across batches. Share your line configuration and current process sequence with us and we will confirm suitability before shipment.
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.
FAQ
Which zinc deposits can be passivated with this bath?
Any zinc layer that has been properly rinsed and is sound. It is used on work coming from alkaline cyanide-free lines and from lines running acid zinc plating chemicals, and it produces the same reddish film on either. What it does not suit is an alloy deposit, because the film forms on zinc metal and alloy layers behave differently.
Does the passivator add a metal layer to the part?
No. It converts the surface of the zinc that is already on the part into a protective film, so dimensions and fit do not change in any measurable way. It is not an electroless plating process and there is no deposit thickness to build; what you control is how much of the zinc surface is converted, through concentration, immersion time and pH.
Will it work over a zinc-nickel alloy layer?
No. Zinc-nickel plating produces an alloy with different surface chemistry, and it needs a passivator formulated for that alloy, which we supply separately. Running a zinc passivator over an alloy layer gives an inconsistent tone and a corrosion result you cannot rely on, so it is worth checking the deposit before the bath goes in.
How clean does the work need to be before it enters the passivator?
Cleaner than most lines assume. Anything carried over from plating reacts with the bath: free cyanide from a cyanide zinc line is the worst of it, but dragged-in acid, zinc and iron all shorten bath life and dull the film. A thorough rinse after plating, a 0.5% nitric acid dip and a second rinse solve almost all of it, and they cost far less than replacing a contaminated bath.
Why does the salt spray result change from batch to batch?
Because the passivator is only one part of the system. Zinc thickness, the plating process that produced the deposit, how well the parts were rinsed, whether a sealer was applied and how the test itself was run all move the hours. When a batch drops below the result you normally get, check the zinc layer and the rinse first, then the bath concentration and pH.
Can the reddish film be sealed for a longer salt spray requirement?
Yes. A chrome-free sealer applied after passivation builds on the passivation film and is the usual route shops providing metal plating services take when a drawing asks for more than the passivate alone delivers. Sealers differ in how much they shift the tone, so check the color after sealing if the red appearance matters to the end customer.
