The investment casting of stainless steel components for the leisure boating sector is a key part of the offering from the Genoa-based specialist EDR Fittings, specifically aimed at suppliers of accessories and manufacturers of technical components.
EDR Fittings’ proposition takes shape and remains at the highest levels of excellence thanks to the collaboration with a network of selected Asian manufacturing partners capable of offering products and treatments of the highest quality in terms of aesthetics, technical specifications, and material purity.
Polishing technologies
“We specialize in the investment casting of articles with special surface finishes, including mirror polishing,” said Ugo Borelli, senior manager of EDR Fittings, and Edoardo Della Rocca, the company’s CEO, in an interview with Nautech.
“We therefore present our clients with a finished product, complete with precision mechanical processing and treatments, ready for assembly on the most prestigious yachts.”
Regarding mirror polishing in particular, the technologies used vary in complexity. Borelli and Della Rocca explained the differences: “The simplest and most cost-effective method involves direct brushing on the raw surface, which may still leave some shadowing.
However, by adding precision mechanical processing before the polishing phase, to smooth out surface roughness, we can achieve perfectly smooth, mirror-polished surfaces, free from image distortions and reflective deformations.”
From simple shapes to complex geometries
This high-end approach, starting from investment casting and followed by surface smoothing through machining and manual brushing, is most suitable for regular, less intricate surfaces that can be reached with specific brushes.
However, EDR Fittings and its trusted network of manufacturing partners, located in Thailand, Vietnam, India and China (where the company operates a facility in Wenzhou), are equipped to handle increasingly complex component shapes.
“For more intricate, hard-to-reach geometries, tumbling is the recommended method. This polishing operation is typically used for rounded shapes like cleats.
The piece is attached to special supports and rotates rapidly within a medium that performs surface abrasion.
By using finer media, high-precision polishing can be achieved, regardless of the piece’s morphology. This type of surface finish is especially effective on complex, non-flat components such as steering wheels, cleats, and locks.”
Increased brilliance with electropolishing
The last but certainly not least important treatment offered by EDR Fittings is electropolishing. This process isn’t performed on raw components but is used to enhance both the brilliance and the corrosion resistance of the part.
It is an electrochemical process that smooths and homogenizes the microscopic ridges on the surface, including those that are hard to reach by brushing, ensuring superior resistance to atmospheric agents. This electrolytic procedure makes the castings more resistant when subjected to salt spray tests.
Each component offered by EDR Fittings receives a specific treatment based on its intended use and the client’s requirements.
“Mechanical processing and mirror polishing are typically applied to deck hardware like fairleads, cleats, gangway accessories, or handles.
These treatments immediately highlight the quality of the product, especially on larger surfaces exceeding 8-10 cm. The goal is always to combine the functionality of the parts with their aesthetic performance.”
It’s important to emphasize that while polishing is certainly very important, the initial quality of the investment casting, free from visible porosity, makes the real difference, as it prevents any potential risk of oxidation.
The rigorous controls that our investment castings undergo regularly ensure excellent quality.”
