Whether for industrial orders, design lacquer finishes or vintage car restorations, wood and glass plastics and aluminum – those who can create effect lacquers such as chrome effects or give chrome parts new, reflective sheen have a great potential. However, this only applies if the shine is also permanent.
A recurring problem in the production of chromium-like surfaces is that long-lasting protection against yellowing, matting or undermining of the very thin mirror layer was difficult to guarantee – especially when the surfaces are exposed to sunlight, weather and mechanical influences. This makes it all the more surprising that a chromium spray system for chemical spray metallization, in short CSM, which was presented by Verchromen24 S.L, now apparently meets extensive quality tests. “Chemical spray metallization was originally developed as a cost-effective alternative to real chromium plating,” explains Verchromen24 S.L Managing Director Ulrich Kuitkowski. “In the meantime, this process of effect coating by the development of fully automatic coating systems on an industrial scale represents a technically mature solution.”
The CSM system of chrome lacquer proves its resistance by passing climate change tests such as the so-called Florida and Arizona tests and by easily completing a 1000-hour salt spray test. “By adding UV inhibitors, among other things, we have optimized the clearcoat material belonging to the CSM system in such a way that we also guarantee UV resistance,” adds Kuitkowski. “The Chrome system thus meets the DIN EN-9227 standard, which is crucial for the automotive industry.”
Best practice
The processing of the robust Chrome system basically corresponds to the procedure customary for spray metallization: A transparent primer (basecod) is first applied to the surfaces to be metallized. It is extremely important that the parts on the surface are clean and free of grease. Painting should be carried out in rooms that are as dust-free as possible. An important point is the attachment of the parts to be finished to holding devices. The type of holding device which is suitable for the respective part depends primarily on the size and shape of the objects. On the one hand, the primer provides the immaculately smooth substrate for the subsequent metal layer, and on the other hand it is distinguished by good wettability and absorbency for water. The primer (basecod) must be dried very carefully – optionally 60 to 150 minutes in a dryer at 60 to 90 degrees or 48 to 60 hours at room temperature.
The next steps follow one another immediately. First, a so-called activation solution is sprayed onto the parts to be processed. The activation process takes place until a closed film of water forms on the surface, which is thus made receptive for the subsequent chemical metal precipitation. Immediately after activation, a washing operation with ionized water takes place.
The excess activation solution is thus thoroughly washed out. Metallization is then carried out using a special two-component gun. In this case, silver salt solution is injected from one gun nozzle and reduction solution is injected from the other nozzle. Both jets mix outside the gun at a certain angle. When the two beams meet, the chemical reaction begins and, consequently, the metal precipitation begins.
The metal film builds up extremely evenly and quickly. The spraying time is 30 to 60 seconds. Thereafter, the mixture is rinsed thoroughly with water again, so that the chemical residues are removed from the objects.
Clear lacquer (Topcoat) gives protection
The freshly metallized parts must then be dried with hot air if possible, in order to avoid water stains. The chemical metallization is thus completed. Finally, the sensitive metal layer must be protected against chemical and physical influences with the CSM clear lacquer (topcoat). “With the CSM technology we can metallize parts of any size and shape,” summarizes Ulrich Kuitkowski. “Suitable substrates are plastic and metal, but also wood or glass.”
It is thus clear for which markets the procedure is applicable: From trade fair construction and advertising to vehicle tuning and refinement to the classic car scene.
The advantage: Due to the stability and robustness of the coating, it is no longer necessary to distinguish between indoor and outdoor applications. Ulrich Kuitkowski: “The DIN EN 9227 standard gives us little room for maneuver: a five-year guarantee for the preservation of the surface must apply in the case of professional application – at least.”