When it comes to popular finishes, powder coating is rated one of the most used. This is because it can be used in anything from outdoor products to appliances to heavy equipment to electronics. This is because powder coating has a lot of advantages over other options that are in the business. In comparison to liquid coatings, workplaces are more solvent-free, they’re easier to clean up, and they have lower line costs. And because powder coatings last cuh a long time, they’re value is much higher to the customer who doesn’t want to replace the coating year after year due to wear and tear.
However, that isn’t to say that powder coatings aren’t without their issues which can halt productivity or result in an inferior product finish. Here are 9 of the most common issues you’re likely to run into and should keep an eye out for.
1. Having Good Grounding
When using powder coating, a lot of science is used to keep everything where it’s supposed to be. The item being covered is grounded while the coating is given a negative charge while it’s in the powder gun. While grounded, the item is given a positive charge so that the powder is attracted to it so that it will adhere to the surface properly. This minimizes any waste or fallout from occurring, which can be dangerous if the proper precautions aren’t taken.
One problem many people face is that there is insufficient grounding in the item being coated. This poor grounding is usually the result of buildup over time on the hooks. It’s important that these hooks be kept clean on a regular basis to prevent this from happening.
Another source of poor grounding is the contacts, such as the conveyor line that the parts are hanging from. By separately grounding these contacts and keeping them clean on a regular basis, the powder will only land on the parts themselves.
2. Keeping the Air Clean
When it comes to applying powder coating properly, air quality is also an important element that needs to be taken into account. The majority of problems that arise can all be traced back to poo air quality. These problems can be the result of dirt and dust, moisture in the air, or the presence of oil. Basically, any contaminants present are going to affect the quality of the powder coating.
To avoid these problems, it’s best to employ a desiccant air filter and dry into the delivery system to remove any particulates that may be present. These filters should be checked on a regular basis to ensure that they are cleaned and or replaced to maintain good air quality.
If you have other concerns about safety and maintaining equipment, you may want to check out the Safety and Regulatory Guidelines for Powder Recovery Systems & Application Equipment.
3. Not All the Same
It would be a fallacy to believe that all powder coatings are exactly the same. So going for the cheapest stuff you can get per pound is not really going to save you any money if it’s not giving you the finish you’re looking for. What you should be looking at is the price per square foot covered to determine which product is going to save you the most on costs.
By going for the cheap stuff, you’re ignoring a lot of the important aspects of the process, such as the resistance to UV light, how durable the coating is, and how uniform the look is. A cheaper product may also not have uniform particles, which is also going to completely ruin the finish. Take the time to do some research into the different powders in the market so that you can save yourself from this hassle in the future.
4. More Amounts to Less
What you want to aim for is getting the right amount of powder applied with the least amount of air necessary. Any more than that, and you’re wasting money and product. Using an air gun that is more powerful isn’t going to get you faster results, and the gun can actually be damaged in the process.
Because the powder is being charged when it’s sprayed through an ion cloud, if the particles are moving too fast, then they’re not going to gain enough charge to cling to the product. This results in having to use more powder to cover the same surface area than you would with the right instrument.
Always ensure that your gun is clean after each use and that the supply lines are free of any kinks. Check the pressure on a regular basis so that everything is in working order. If you’d like to learn more, visit the Custom Wytelyne website.
5. Size is Important
The great thing about powder coating is that any spray that hasn’t adhered can be gathered up and used again. The downside to this is that using only reclaimed material for coatings is very expensive and isn’t time-efficient.
This is due to the way the powders work. They’re usually manufactured in particular size ranges for various jobs. They’re usually uniform throughout to produce an even coating, but the particles become smaller and smaller every time they’re sprayed and reclaimed again. This can result in an uneven coat that isn’t going to adhere as well as it should. The only way to combat this problem is to constantly add fresh material and worry about reclaiming material after the job is done.
6. Stick to the Recipe
During the curing process, there are only three results that can take place: getting a proper cure, under-curing, or over-curing. So how do you prevent over-curing or under-curing from occurring?
Firstly, the temperature of the part being coated must remain at a constant for a set period of time. Any changes can result in a poor cure that won’t last very long. However, under-curing is preferable to over-curing, as it means the process just needs to be applied again for a full cure. An under-curing results in poor adhesion of the powder, less flexibility, and a less glossy finish.
Over-curing, on the other hand, results in discoloration. This negates the possibility of applying another coat on top to cover it up. That’s why it’s important to check the time and temperature for each powder so that you’re not wasting any product.
7. Preparing the Surface
The look of the coating is only going to be as good as the quality of the surface it’s being applied to. If you ignore the pre-treatment steps, then you’re going to end up with a lot of problems, such as less adhesion and resistance to corrosion. Preparing the surface of your product properly beforehand will always yield the best results.
It’s also important to note that different items require different pre-treatments. A desk doesn’t follow the same steps as a bicycle. Doing some research beforehand will help you to achieve the best end result.
8. Proper Storage
Where you store your coatings is very important. They require a cool and dry place, in anything below 80 degrees Fahrenheit with humidity levels less than 50%. Powder coatings that are low-cure may even require colder temperatures for storage. The reason for these requirements is that the powder naturally absorbs moisture from the air, causing it to cake up. And excessive heat can result in the powder curing and fusing together while in storage, resulting in a finish that’s like sandpaper when the powder if applied. That makes the finish extremely brittle and unpleasant to look at. If this happens, the only solution is to get rid of the powder altogether, as the entire batch is unusable.
9. Avoiding Cross Contamination
When you’re changing between colors, cross-contamination is common and can lead to finished parts being rejected. To eliminate the chances of this, spray guns have to be completely cleaned before another color can be added to it. Not only does this remove the wrong color being added to the product, but it eliminates the risk of two incompatible powders being added to the same thing. This only complicates the curing procedure and will result in an uneven finish.
All equipment and even the booth should be completely cleaned in order to avoid cross-contamination. Removal of the powder also prevents the powder getting stuck int he air conditioning systems, which can wear down and break over time with all the powder getting stuck in it.
When working with powder coatings, is essential that proper procedures be followed to the letter. This is not only to ensure the safety of yourself and those around you, but you’ll have better quality products at the end of the process. Ensure that everyone is aware of the common practices to minimize these problems in the future, and oversee the application of new powders so that the proper steps are being followed. After all, your business is likely to suffer for it if these practices aren’t turned into habits.
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