What's the Difference Between Electro Galvanized and Hot Dip Galvanized?
Often, in the fence world, the word "galvanized" is used to describe fence materials. However, not all galvanizing is quite the same. Let's take a closer look at the difference between electro galvanized and hot dip galvanized fence materials, so you can see what the similarities and differences are.
What Is Galvanizing?
Before we get into the details of what electrogalvanizing is, what hot dip galvanizing is, and which one might be better, it's important to know what galvanizing is and what it's designed to do.
Galvanizing is a thin coating of zinc that is deposited on the surface of steel to provide an anti-corrosive coating. It is a "sacrificial" coating, which means it exists to take damage, so that the steel below does not. It is also somewhat self healing, so if there is minor damage to the zinc coating on the surface, the surrounding zinc will "move into" the damaged area to repair it.
What Is Hot Dip Galvanizing?
Hot dip galvanizing is a type of galvanizing where a steel item is immersed in a bath of molten zinc.
This deposits a layer of zinc on the surface, and also creates a thin layer of a steel / zinc alloy at the place where the two metals meet.
Hot dip galvanizing is usually a lot thicker than electrogalvanizing, and it doesn't look as smooth. However, it does provide better corrosion resistance.
It's important to remember that the size of the galvanizing bath will determine what size items can be galvanized, so there are some limitations on what can be galvanized this way.
What Is Electrogalvanizing?
Electrogalvanizing is a type of galvanizing where the steel object is immersed in a zinc salt solution. Electricity is then applied, and this causes the zinc to "electroplate" the surface of the steel.
The coating applied by electroplating or electrogalvanizing is thinner, and therefore less corrosion resistant, but it does usally look better.
Electrogalvanizing is not suitable for very corrosive environments, and it's usually a good idea to "duplex" coat fences that are electrogalvanized, by applying another layer of corrosion resistance like paint or powder coating.
What Else Do You Need to Know About Electrogalvanized vs Hot Dip Galvanized Fences?
Hot dip galvanized materials usually cost more than electrogalvanized, because there is more zinc used in the process.
However, hot dip galvanizing also provides superior corrosion resistance, which is a factor you should consider. A better protected fence will last longer, which might make the added expense worthwhile.
When you are shopping for a fence, be sure to specify if you want hot dip galvanized materials. If you just say "galvanized" you never know what you might be getting!
