Why is Fettling Important in Metalwork?
Fettling serves two main purposes: it improves the aesthetic quality of metal parts, and it ensures proper adhesion for subsequent coatings. For example, if a metal part is going to be powder coated, any rough edges or excess material can interfere with the coating process. The coating may not adhere properly, leading to imperfections that will compromise both the appearance and the durability of the final product.
In the case of structural steel, architectural coatings, and other industrial applications, the aesthetic quality and durability are paramount. No one wants to see rough patches, sharp edges, or discolouration on what should be a sleek, smooth, and protected surface.
Fettling in Different Industries
Fettling plays an essential role in multiple industries, such as:
- Automotive: Fettling ensures that car parts have a smooth, polished surface before being painted or coated.
- Construction: Metal frames and supports need to be fettled to prevent sharp edges and achieve a professional finish.
- Aerospace: In an industry where precision is vital, fettling ensures that components meet the exacting standards required for safety and functionality.
Common Methods and Tools for Fettling
In modern metalworking, fettling can involve a range of techniques and tools, including:
- Hand Tools: Files, chisels, and sandpaper are often used for minor fettling work, especially when precision is required.
- Grinding Wheels: For larger jobs, a grinding wheel can quickly smooth out a surface or remove unwanted material.
- Pneumatic Burrs: High-speed rotary tools can be used to remove rough edges and clean up intricate areas on metal components.
- Shot Blasting: This process uses high-velocity abrasives to clean the surface, effectively “fettling” it before coating.
Fettling vs Grinding: Is There a Difference?
Many people confuse fettling with grinding, but while they are similar, they have distinct purposes. Fettling is typically a finishing process focused on removing imperfections, while grinding often refers to reshaping or resizing a metal part. In essence, fettling is the finer, more detailed cousin of grinding, focusing on surface quality rather than form.
this picture shows the Elcometer reading after fettling and its down from 104 to 76.5, so nearly a quarter of the protective zinc has been taken off.