Blue Chromate Conversion Coating – Chromium(III) Blue Passivation for Zinc & Zinc-Plated Parts
€19.00
Available, delivery time: 1-2 days
Product information "Blue Chromate Conversion Coating – Chromium(III) Blue Passivation for Zinc & Zinc-Plated Parts"
Blue Chromating / Blue Passivation for Zinc – Corrosion Protection and Decorative Finish
Protect and enhance the appearance of zinc-plated surfaces
This Blue Chromating Solution for zinc surfaces is designed for the post-treatment of electroplated zinc coatings. It helps protect zinc surfaces against premature oxidation and tarnishing while improving their decorative appearance. Depending on the immersion time, the treatment can produce a glossy, bluish-iridescent or increasingly matte finish.
Blue passivation is particularly suitable for components that have been electroplated with zinc. It helps reduce the tendency of zinc surfaces to tarnish and provides a more uniform, attractive finish.
Another advantage is its ability to reduce or remove slight yellowish discoloration that may occur after zinc plating due to certain brightening additives, provided the surface and process are suitable.
The treatment is carried out without an external electrical current at room temperature. No electroplating power supply or additional heating is required.
Key Benefits
Blue chromating and blue passivation for suitable zinc surfaces
Post-treatment for electroplated zinc coatings
Helps protect against zinc oxidation and premature tarnishing
Creates an attractive bluish-iridescent finish
Can reduce slight yellowish discoloration after zinc plating
Adjustable surface appearance through different immersion times
Electroless application without an external power supply
Suitable for room-temperature processing
Glossy to matte finishes, depending on treatment duration
Designed for decorative post-treatment of suitable metal surfaces
Applications
Blue chromating is primarily used for the post-treatment of electroplated zinc components, including:
Screws, nuts and fasteners
Steel components with electroplated zinc coatings
Metal fittings and small components
Zinc-plated parts requiring an improved decorative finish
Zinc-plated components with slight yellowish discoloration caused by brightening additives
Chromating and passivation processes are also used for certain aluminium surfaces. However, suitability of this specific product for aluminium must be confirmed against the manufacturer's technical specifications.
Technical Specifications
| Property | Specification |
|---|---|
| Product | Blue Chromating / Blue Passivation |
| Application | Electroless post-treatment |
| pH value | 2–3 |
| Operating temperature | Room temperature, approx. 20–30 °C |
| Recommended immersion time | 15 seconds to 2 minutes |
| Surface finish | Glossy, bluish-iridescent to matte |
| Main application | Post-treatment of electroplated zinc components |
Surface Finish Depending on Immersion Time
The immersion time influences both the appearance and the achievable corrosion protection. The following times are guidelines and may vary depending on the condition of the zinc coating, temperature and plating process.
| Immersion time | Typical effect |
|---|---|
| 5–15 seconds | Yellowish discoloration caused by brightening additives may disappear |
| 15–45 seconds | Glossy, bluish-iridescent surface |
| 45–120 seconds | Increasingly matte finish; corrosion protection may increase |
For a glossier result, a shorter immersion time is recommended. If a more matte appearance is desired, the immersion time can be increased gradually.
Inspect the surface regularly and adjust the treatment time to achieve the desired finish.
How to Use Blue Chromating Solution
1. Prepare the workpiece
The workpiece should be freshly zinc-plated, clean and free from grease, dirt and residues. Appropriate surface preparation is essential for achieving a uniform result.
2. Treat the workpiece promptly after zinc plating
The blue chromating treatment should be carried out as soon as possible after zinc plating. If too much time passes, a passivation or oxide layer may form on the zinc surface, potentially interfering with or preventing uniform treatment.
3. Immerse the workpiece
Pour the solution into a suitable, chemically resistant container. Fully immerse the zinc-plated workpiece for the desired period. The recommended immersion time is 15 seconds to 2 minutes.
4. Monitor the surface
Observe the colour development during treatment. A short immersion may reduce yellowish discoloration, while a somewhat longer treatment can produce a bluish-iridescent finish. Longer immersion times generally result in a progressively more matte appearance.
5. Post-treatment
Remove the workpiece once the desired result has been achieved and continue with the post-treatment specified by the manufacturer. In particular, follow the manufacturer's instructions regarding rinsing and drying.
Important: The Zinc Coating Is Partially Attacked
Blue chromating partially removes the existing zinc coating. According to the supplied product information, the zinc loss may reach up to 2 µm after an immersion time of four minutes.
Avoid excessive treatment times, particularly when working with thin zinc coatings or components with tight dimensional tolerances. Follow the recommended treatment times and inspect the surface regularly.
The achievable protective effect depends on the quality and thickness of the original zinc coating, surface preparation and actual process conditions. Blue chromating cannot reliably remove existing oxidation or corrosion damage.
Electroless Processing at Room Temperature
The treatment requires no external electrical current. At an operating temperature of approximately 20–30 °C, additional heating is normally unnecessary. This makes the process straightforward and convenient, particularly for post-treating small and medium-sized zinc-plated components.
Blue Chromating / Blue Passivation from Betzmann Galvanik
Give electroplated zinc components an attractive finish while helping protect the zinc surface against premature tarnishing. By adjusting the immersion time, the surface appearance can be influenced from glossy and bluish-iridescent to matte.
Betzmann Galvanik – products for electroplating, post-treatment and professional surface finishing.