The hot-dip galvanizing process is pretty much what it sounds like; fabricated steel is dipped into an appropriately sized vat of molten zinc to create a strong protective coating. Manufacturers in many industries look for galvanization to protect products against corrosion. Benefits of this process include
Hot-dip galvanizing is a time-tested process that creates a strong alloy coating of steel, iron, and zinc. However, in order for the bond to be fully developed, there’s some surface preparation that must be completed.
Adequate Drain Holes
Before products arrive at galvanizing plants, steel and iron surfaces must be prepared. The first step is to inspect the metal products. It must have an appropriate amount of vent and drain holes. Once this has been approved, the steel is ready for the next step.
The next step in surface preparation is to remove all organic contaminants. There are generally two steps in this process. The first is a chemical bath that degreases the steel and removes grease, dirt, and oils. The second step is to bathe the steel in a pickling acid. This removes rust and mill scale from the steel.
Finally, it’s necessary to protect the surface of steel products from oxidation. This can be done by dipping the product into a flux bath. Fluxes are typically used in extractive metallurgy and metal joining. In this case, it is a chemical cleaning and purifying agent that prevents oxidation and has the added benefit of aiding the galvanization reaction at the galvanizing plant.
Additional Cleaning Steps
There are some things the cleaning chemicals can’t remove. These include weld slag and spatter, burrs, heavy layers of mill scale, varnishes, epoxies, sand, oil-based products, vinyl, asphalt, and thick deposits of grease. If these are present on the steel surface, it may be necessary to clean the area by hand, with an abrasive blast cleaner, or power tool.
Galvanization is a straight-forward and valuable source of protection. Be sure to get the best results by preparing your products before taking them to the plant.