The key difference between galvanizing and tinning is that galvanizing is the application of a thin coat of zinc on a surface, whereas tinning is the application of a thin tin layer on a surface.
Galvanizing and tinning are industrial processes that are important in preventing the rust formation on metal surfaces. Galvanizing is the industrial process of applying a zinc layer on a metal surface for the protection from corrosion, while tinning is the process of applying a thin layer of tin on a metal surface.
CONTENTS
1. Overview and Key Difference
2. What is Galvanizing
3. What is Tinning
4. Side by Side Comparison – Galvanizing vs Tinning in Tabular Form
5. Summary
What is Galvanizing?
Galvanizing is the industrial process of applying a zinc layer on a metal surface for the protection from corrosion. We call the process of applying this zinc layer “galvanization”. Particularly, this application is made on steel or iron surfaces.
There are different types of galvanization, such as:
- Hot dip galvanization – immersion of the item in molten zinc
- Continuous galvanizing – a form of hot dip galvanization, but this method forms a thinner zinc layer; thus, the corrosion resistance is comparatively less
- Thermal spray – spraying semi-molten zinc on to the item
- Electroplating– using the item and zinc metal as electrodes in an electrochemical cell
- Mechanical plating – electroless method to deposit the coating using mechanical energy and heat
Among these five types, hot dip galvanization is the most common method. It is the process of coating a zinc layer on a metal in order to protect that metal from corrosion. We can denote it as HDG. This process has three major steps: surface preparation, galvanizing, and inspection.
During the surface preparation step, we have to hang the steel item using wires or place in an appropriate rack. Then the steel goes through three cleaning steps: degreasing, pickling and fluxing. The degreasing step removes the dirt on the steel surface. Pickling step removes mill scale and iron oxide. Later in fluxing step, it removes any other oxides present on the steel surface and forms a protective layer which can avoid any further oxide formations.
During the galvanizing process, we need to dip the steel in a molten bath of zinc, which has at least 98% zinc. Here, the iron in the steel surface tends to form a series of zinc-iron intermetallic layers and an outer layer of pure zinc. In the step of inspection, we need to inspect the coating. Moreover, we need to determine the quality of the surface zinc layer.
What is Tinning?
Tinning is the process of applying a thin layer of tin on a metal surface. Mostly, this type of coating is done with wrought iron sheets or steel. The resultant product of the tinning process is called a tinplate. Also, this term is widely used for the coating process of a metal with solder before soldering.
Most often, this process is useful in preventing rust formation on the metal surface. However, it is also commonly used to the ends of stranded wires that are useful as electrical conductors to prevent the oxidation and in keeping them from fraying or unravelling when the conductors are used in various wire connectors such as twist-ons. Nowadays, the most common use of tinplate is to manufacture tin cans.
What is the Difference Between Galvanizing and Tinning?
Galvanizing and tinning are industrial processes that are important in preventing the rust formation on metal surfaces. The key difference between galvanizing and tinning is that galvanizing is the application of a thin coat of zinc on a surface, whereas tinning is the application of a thin tin layer on a surface. Moreover, galvanization involves coating steel or iron surfaces while tinning usually involves sheets of wrought iron or steel.
Below info-graphic tabulates side by side the differences between galvanizing and tinning.
Summary – Galvanizing vs Tinning
Galvanizing and tinning are industrial processes that are important in preventing the rust formation on metal surfaces. The key difference between galvanizing and tinning is that galvanizing is the application of a thin coat of zinc on a surface, whereas tinning is the application of a thin tin layer on a surface.
Reference:
1. “Galvanizing.” Galvanizing – an Overview | ScienceDirect Topics, Available here.
Image Courtesy:
1. “Galvanizing skimming” By Babalon246 – Own work (CC BY-SA 4.0) via Commons Wikimedia
2. “Inside of a tin platted can” By Schtone – Own work (Public Domain) via Commons Wikimedia