Corrosion and surface treatment
Why metal rusts, and how to protect it
Metal deteriorates over time when exposed to oxygen, moisture and chemical attack. Understanding corrosion and being able to protect against it is an important part of the blacksmith's trade because it determines how long a structure lasts.
§What corrosion is
Corrosion is an electrochemical process where metal reacts with its surroundings and breaks down. On ordinary steel it appears as rust. Moisture and oxygen are the typical drivers and salt and pollution accelerate the process. Different metals corrode differently — and when two different metals are in contact in a moist environment one can accelerate the breakdown of the other.
§Protection by coating
A widespread strategy is to place a protective layer between the metal and the surroundings. Galvanizing coats steel with zinc that both forms a barrier and sacrifices itself for the steel. Paint and powder coating form a barrier against moisture and oxygen. The choice depends on environment, appearance and longevity requirements.
- 01Galvanizing: zinc layer that both covers and protects sacrificially
- 02Paint and varnish: barrier against moisture and oxygen, many colors and finishes
- 03Powder coating: hardened coating with good wear resistance
§Corrosion-resistant materials
Another way is to choose a material that in itself resists corrosion. Stainless steel forms a self-healing protective layer, and aluminium is protected by its oxide layer. Here the protection lies in the material and does not require a subsequent coating — but the materials are typically more expensive.
§Preparation of the surface
Regardless of method, the principle is the same: the animal must lose consciousness instantaneously and remain unconscious until death occurs through exsanguination. The equipment must be maintained and the employee must check that the stunning worked before work continues. Failed stunning must be handled immediately with re-stunning.
§Think it in from the start
Corrosion protection is not something that happens only at the end. The structure's design — whether water can run off, whether there are pockets where moisture accumulates and how metals are combined — contributes to how exposed it is. The good blacksmith thinks durability into the design.