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.
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There are a number of methods by which steel is protected from corrosion. One of the most effective methods of effectively protecting steel from corrosion is galvanic protection. This protection simply works by covering the surface of the steel with a metal which will preferentially corrode and protect the steel at the time when it comes with contact with any electrolyte such as water.
All of the metals and their alloys have a characteristic called the electrochemical potential. Now, when the metals that have a high electrochemical potential comes in contact with a metal having low electrochemical potential tend to corrode. This is the reason as to why galvanic coatings are applied to steel since these galvanic coatings have a higher electrochemical potential as compared to steel and as a result the base metal is saved from corrosion whereas the coating is corroded.
Methods of Galvanic Protection
- There are a number of ways by which galvanic protection is offered to steel for preventing it from corrosion. The most common methods used in this regard are as follows.
Hot Dip Galvanisation –
- Galvanising refers to the method of application of a continuous layer of zinc to the surface of steel. In the method of hot dip galvanisation, the steel is dipped into a bath of molten zinc which allows zinc to adhere to the surface of steel.
- This process involves a lot preparation of the surface of the steel and a number of other steps for the process to be effectively completed.
Zinc Rich Primers –
- Zinc rich primer is basically a liquid applied coating on the steel that has a microscopic spheres of solid zinc metal that are held together with a resin.
- There are a number of options for the types of resins to be used. The most commonly used resin for the zinc rich primer is epoxy resin. The coating so formed over the steel help in the prevention of corrosion.
- Now, it can be clearly understood that both of these methods offer galvanic protection of the base metal steel from being affected by corrosion so as to keep them functional for a longer duration of time.
A Comparison Between the Two Methods
A comparison between the two methods that is hot dip galvanisation and zinc rich primers would prove which of the process is a better one.
- The service life of hot dip galvanisation is more as compared to the inorganic zinc rich primer which means when subjected to the same conditions, hot dip galvanisation offers a longer protection as compared to the inorganic zinc rich primer.
- Thus, it is clear that hot dip galvanisation offers more galvanic protection as compared to the zinc rich primers in the same environment.
- Both hot dip galvanising as well as zinc rich primers can be used with a top coating but many times there is a top coating used for additional protection for the preservation of the galvanic layer and for aesthetics along with the protection of the zinc layer at the time when the service conditions are acidic or alkaline in nature.
- Now, zinc being amphoteric in nature does well in the pH neutral environments but quickly deteriorates in case of extremely low or high pH levels.
- This is exactly where surface preparation comes into play. Here, hot dip galvanisation has a better prepared surface without any gaps.
- But in case of top coating of the zinc rich primers, it needs to be carefully done to release the air in the gaps for properly
- sealing the surface which is not needed in hot dip galvanisation. Thus, hot dip galvanisation is a better option as compared to the zinc rich primer.
Since, hot dip galvanisation offers a better solution, it is readily used in the crash barriers, cable trays, earthing material and a number of others. But at any point of time, you are looking for hot dip galvanizing services in Gujarat, make sure you choose a trusted and a reputed one for the best solutions. Tanya Galvanisers would undoubtedly be a very good choice in this regard. With its several years of experience in the field of hot dip galvanisation, you can be assured of getting best of the services.
Get in touch with us call: +91 8000842648