If you’re just getting into the world of powder coating you surely have read or heard about “hot-flocking” but few understand why it can be beneficial. We decided to put together a few tips about the process of Hot Flocking powder on an item when powder coating. Read more below!
So what is “Hot Flocking”? Hot Flocking is the process of pre-heating an item and immediately spraying powder onto the part while it is still hot. This helps with adhesion, but can be VERY tricky if you aren’t careful. Start by cleaning your parts as good as possible, including any paint, grease or oil. I then like to run the part through the heat and cool cycle once. This consists of heating the part past the curing temperature of your powder (check your powder bottle for the temperature). I then do one last wipe down with Acetone and then put it back in the oven and heat it to the curing temperature until the ENTIRE part is reading the cure temperature. Using an IR thermometer is key here. Larger cast parts like engine parts or even dense items like a car wheel will take longer to fully get the part up to temp. I like to prepare my powder in my powder gun and my work area while the parts are getting hot, this way I’m fully prepared to spray when it’s time.
Once the part is up to temperature immediately pull it out of the oven and set it by your powder gun. You don’t need to even use the ground clip here as the powder will instantly “cling” to the part because it melts as soon as it hits the surface and starts curing. You need to move quicly as the powder will only cling when the part is hot. If you take too long to apply the powder it won’t stick well and the powder will start applying “dry” or won’t stick at all (if the ground clip isn’t attached). You also want to be sure to keep track of how much powder or how many passes you’ve made over the part. The powder starts flowing out almost on contact and it can be hard to tell how thick your film build is. I’ve seen people apply so much the powder actually runs and then hardens as a thick, solid run. This means you need to grind the run off and recoat the entire part; not very fun!
Hot Flocking is really handy when you’re doing multiple coats on a part and you’re having problems with getting a good static charge on the part for the additional coats. This is also necessary when you’re using an entry-level fixed voltage powder gun as it won’t have the power to pull the charge through the part. Again here you want to be careful you don’t overcoat the part as it may change the hue or finish of the top coat you put on.
Finally, Hot Flocking is great for coating parts that have little or no conductivity. This includes non-metallic materials like glass! The hot part will allow the powder to adhere and cure just like metal leaving a durable, beautiful finish! Read more on how to powder coat glass here.