Hot dip galvanizing is the process of application of a zinc coating to steel and iron. The process involves dipping of both unfabricated as well as fabricated pieces of steel, or iron into a bath of molten zinc at about 840 degrees Fahrenheit. Galvanization is done to enhance the ability of the base metal that is iron or steel to last for a longer duration of time without getting corroded or rusted. It is precisely where the importance of galvanizing lies.
Now, before the hot dipped galvanizing process a lot of steps are carried out to make sure that the entire process is carried out in a smooth and uninterrupted manner. In addition to this, utmost care is taken during the entire process to ensure that the intended results are obtained. The final step in the process of galvanization is inspection. Inspection of hot dipped galvanizing process refers to process of checking of the end product after the completion of the galvanizing process. The inspection of hot dip galvanizing process primarily focuses on the following two points.
The thickness of zinc coating on the base metal
The thickness of the coating determines the time frame of protection. Usually, the thicker is the coating of zinc, the longer is the expected life span of the base metal. Here are a few important things to consider.
- Local coating thickness – It is the mean value of the zinc coating that is obtained from the specified number of measurements within an area of reference
- Mean coating thickness – It refers to the average value of the local thicknesses on the different base metal pieces in the control sample
The appearance of the zinc coating on the base metal
The appearance after the hot dipped galvanization process refers to the visual inspection that checks for any sharp drops or points or any kind of irregularities. Here are the essential points to consider while inspecting the appearance of the zinc coating.
- While inspecting visually, the coating of zinc must be free from any sharp points or drops
- There should not be any irregularities
- No areas should be uncoated
- Presence of any kinds of lighter or darker grey spots
All the points mentioned above should be carefully inspected to make sure that the end product of hot dipped galvanization process are perfect in all aspects and are ideally suited for the intended purpose of use.
Powder coating on hot dip, as can be understood from the name, is a procedure to apply a coating of a special powder on steel that is hot dip galvanized. This particular coating of powder applied on the hot dip galvanizing process provides a significant amount of flexibility as well as a long life. It is precisely the reason as to why powder coating on hot dip galvanized steek has become so popular in recent times. Now, there are three of the major problems that are usually associated with the powder coating on hot dip galvanizing.
- Pin holing of the coating – It is caused by the formation of small air bubbles in the coating at the time of curing or stoving cycle. These bubbles give rise to small craters, and are unsightly. At the same time, it reduces the life and durability of the product.
- Poor adhesion – In the final step of hot dip galvanizing process, water quenching is involved usually in a weak dichromate solution. If it is not done appropriately, the adhesion of the powder coating tends to be quite poor, and hence ineffective.
- Incomplete curing – The powder coatings are thermosetting resins that cross link to their ultimate organic form when they are maintained at a temperature of 180 degrees Celsius for approximately ten minutes. The curing overs are designed to do the task efficiently. But if the curing is incomplete, the coating would not be perfect.
To get rid of these problems, it is of immense importance to follow a few of the most essential tips in this regard for perfect powder coating on hot dip galvanized steel.
- Carry out the hot dip galvanizing process but do not chromate or water quench
- All the drainage spikes as well as the surface defects should be mandatorily removed
- Powder coating should be done within a maximum of twelve hours after galvanization
- Precautions need to be taken to make sure that the surfaces do not get wet, and ensure that the item is not left outside
- It is essential to keep the surface clean without any kind of contamination before the application coating
- In case any contamination, the surface should be necessarily cleaned with compatible detergent or solvent before the application of powder coating
- It is ideal to pre treat the hot dip galvanized steel with zinc phosphate to make sure that the highest adhesion is obtained, and most importantly the surface should be perfectly clean before the treatment
- Before the application of powder coating, the work should be pre heated
- Finally, it is to be made sure that curing is perfect and the correct curing should be checked by solvent testing
Keeping all these tips in mind would make sure that the intended results are obtained. So, at any point of time, you are search of the best hot dip galvanizing services in Vadodara, Prashant Galvanizers would undoubtedly be the best option. We are a leading hot dip galvanizing service provider to make sure to provide the users with premium quality services. Moreover, it is recommended to choose a trusted, reputed, and reliable service provider like Prashant Galvanizers if you wish to get the best solutions in this regard.
For more information on hot dip galvanizing by Galvanizers, click the link: