How to Remove Powder Coating Methods and Tips

In this post, we’ll know about, How to Remove Powder Coating and why it is necessary.

For its tensile strength and adhesion, powder coating is recognized. The same qualities that make the coating so appealing also pose substantial challenges if you need to remove the coating.

Let’s know the reasons of remove powder coating

Renovation: to keep it looking new and shiny

Repairing errors: made during the powder coating process, particularly by beginners who are prone to doing so

Cleaning: It is necessary to clean after each powder coat application to prevent unnecessary accumulation while you work on the job.

Remember the Factors When Choosing a Powder Removal Method

• the preferred surface texture
• laws governing the environment and public health
• The budget for a project
• Section size and construction materials
• Speed of stripping

Powder Removing Method

There are four major ways to remove powder coating:

• Chemical Stripping
• Mechanical disassembly and media blasting
• Cooling and heating
• The use of lasers

1. Chemical Stripping

Using hot or cold stripping chemicals, chemical stripping processes dissolve, melt, and swell the powder coating as they work. The coating then separates naturally or occasionally needs to be washed off. Powder coating is entirely and uniformly eliminated using this method. Handle cold chemical strippers cautiously since they contain potentially harmful solvents.

Given the volume of production and frequency of powder removal, the numerous chemical strippers that are widely available are developed for a variety of applications. You might need to brush off any remaining powder coating if it is present on the surface. Make sure you have a chemical disposal plan in place as well as an appropriate respirator on available.

It is essential to make sure both the person and the surroundings are safe when using this process.

Advantages

• Completely removes the powder coating from a surface, leaving you with a smooth, clean surface after the process is over.
• Chemical strippers work well for both regular and irregular little output. The cost of chemical strippers and the necessary tools is affordable.

Disadvantages

• Poisonous compounds included in chemical strippers could be dangerous to handle because they easily burn the user’s eyes and skin. Users must always wear the proper personal protective equipment (PPE), such as a face mask.
• Chemical degreasers remove oil from surfaces without leaving any residue behind. An anchor profile, a tiny surface feature, provides a surface to which a new coating can adhere. This is essential as it ensures the durability of the recently placed coating.
• Used stripper and water must be disposed of in line with the relevant health and safety requirements because they are typically recognized as hazardous waste. This leads to a costly and carefully monitored disposal process.
• Chemical strippers need an extra step because you have to leave behind an immaculately smooth surface; as a result, you might need to scrape off the surface because it is usually too smooth.
• There are usually very tight requirements for the environment, safety, and health that apply to chemical strippers.

2. Mechanical stripping and media blasting

Mechanical cleaning systems can be batch-operated or automated. Sand, water, glass beads, steel shot, plastic media, slag, oxides, and garnet are some of the blasting materials used by mechanical paint strippers. These are thrust in the direction of the covered substance at high speeds and pressures, abrading the coating.

Dustless blasting doesn’t require a blast cabinet or other forms of confinement, whereas dry blasting can be done in either a blast cabinet or a blast room.

The surface profile and coating removal speed are influenced by the abrasive media selection. The metal surface is left with an extremely uneven and rough texture, even if harsh abrasive particles remove the coating more quickly. Cleaning takes longer even if soft blasting media, like soda or plastic, ensures a smooth metal surface.

If you intend to remove powder coating by sandblasting, choose an aggressive blast media, such as steel grit or aluminum oxide. The time needed to remove the powder coating is shortened with the help of these strong media. Additionally, it’s important to keep in mind that sandblasting manufacturing requires compressed air; as a result, before starting the job procedure, make sure to buy a sizable air compressor.

Tips for Effective Sandblasting

Wet Vs. Dry Powder Coating Blasting

This technique is uncommon because it takes so long to remove powder coating with conventional sandblasting. It is advised to utilize dustless blasting rather than dry blasting because it is faster. This is due to the fact that the water it produces boosts the machine’s output of mass and energy, which significantly improves speed.

Wet Abrasive Blasting

Wet abrasive blasting includes wetting the blast media prior to impacting the surface, just as traditional sandblasting. The benefit of this technique is that it creates less dust, allowing users to work in a variety of locations with less setup and cleanup expenses. The end result is always a smoother and more level surface.

Portability Advantage

Since water is used to eliminate dust, dustless blasting is environmentally friendly. It also has the advantage of not needing heavy confinement, which makes it portable and simple to use at the locations of your clients or any other suitable site.

Better reapplying paint or coating

Different anchor profiles can be made using various abrasives. Given that a strong anchor profile serves as the foundation for an excellent coating reapplication, this is a desirable quality.

Rust Potential

Please rinse the metal that has been shot in it with the available rust inhibitor. For 72 hours, rust will not occur.

Advantages

• Its application benefits both small parts and large batch operations.
• It is handy because it is portable.
• It eliminates the need to scratch the surface and leaves behind an anchor profile that ensures proper reapplication.

Disadvantages

• Comparing it to heat and chemical procedures for powder coating removal, it is too slow for high production levels.
• It is expensive and may go up in price if a blast room is required.
• It requires compressed air, which may only be available in specific working settings.

3. Thermal cleaning

The thermal cleaning process is sometimes referred to as “burn-off,” “bake-off,” and “fluidized bed.”

Thermal cleaning involves burning the coating off at extremely high temperatures. After treatment, chemicals and ash residue are usually eliminated by water rinsing or blasting. For optimal results, make sure the parts are robust or temperature-resistant to 650°C.

This procedure is preferable because it eliminates the dangers, risks, and challenges involved in the chemical stripping method of coating removal.

One option is to use a fluidized bed system, bake-off method, or burn-off method to remove powder coating. The different methods of operation are demonstrated by the quantity of heat applied, the different temperatures, and the speed at which the powder coating is removed.

Bake-off cleaning system: cleans in 3 to 6 hours at 640 to 750 degrees Fahrenheit. Wash off the burnt-off powder coating to stop it from sticking to the surface. The water-misting systems integrated into oven parts increase the burning rate, which reduces damage.

To burn off the system, temperatures between 1000 and 1200 degrees Fahrenheit are required. They are typically configured as inline processes. cleaner since it takes less time to clean. It is suitable for high production facilities because of its purifying qualities and extreme temperatures. After the burning is finished, the fire is put out with water, and any ash that remains is cleared away.

At 800 degrees Fahrenheit, fluidized bed stripping systems are in operation. Heat is used to dissolve the coating on the pieces, and the medium’s abrasiveness removes any leftover material. uses inert elements like sand and oxides as a heat transfer medium. The medium fluidizes when heated and under pressure from air or gas. There is no need for additional cleaning after the treatment.

Advantages

• It does not have the tight environmental constraints associated with chemical stripping.
• One of the quickest ways to complete the process, even for huge productions, is to use heat to remove powder coating. Operators highly favor it as a result.
• Thermal cleaning is not only rapid, but it is also risk-free, efficient, and presents little danger to the environment, public health, or safety.

Disadvantages

• High power requirements – It takes a lot of power, which is also expensive, to maintain such a high temperature. As a result, there is a significantly smaller area where such a high amount of power is available.
• High likelihood of warping or damaging goods – The necessity for extraordinarily high temperatures to remove powder coating is the reason for this. This approach also leaves behind the anchor profile needed for coating reapplication.
• Processes that take longer: This method requires additional cleaning or wash steps to remove any burnt-on powder residue before moving on to the next stage.

4. Laser

Learning that lasers were developed specifically to remove coatings from a product surface excites most operators. It is essential to ensure that the background is properly prepared and that the technique will work with the thickness of the powder coating you want to remove because it is pricey.

Advantages

• works on many different surfaces, both big and little.
• free from any environmental restrictions, and safe.
• The surface is just slightly changed because no heating is applied.

Disadvantages

• The fact that it is an expensive endeavor limits its utilization.
• The user may slightly regress because laser surface removal does not profile the surface.

Conclusion

You can compare notes and choose the best alternative using the aforementioned options depending on the project’s magnitude, how frequently powder needs to be removed, and its financial repercussions. However, the general recommendation is as follows:

Sandblasting is economical and necessitates fewer preparation processes.

A chemical stripper is the best tool for sporadically removing powder coatings.

Batch burn-off ovens are best suited for high production instances. Even though it is the most costly strategy, it is also one of the fastest and most efficient ones.