Painting metal parts can be a royal pain. It’s time consuming, messy and imprecise, with runoff and dripping and uneven coats. Even worse, after you paint it, the coating isn’t permanent. It has to be touched up time and again, and eventually the paint gets so thick the whole thing needs to be stripped and redone. Powder coating can be a great alternative that provides a rock hard permanent and even coating with a minimum of fuss. Here’s how the powder coating process works.
Understanding Powder Coating
The powder coating process is an alternate means of coloring metal parts, whether they’re automotive parts or pieces of a model. The process uses a specialized pigment that starts off as a powder that is applied to the dry parts (hence the term, “powder coating”).
When exposed to heat and electrical charges, the powder goes through a chemical bonding process and melts, hardening into a solid surface that perfectly contours to the item covered. It is eco-friendly, inexpensive and far more durable than paint.
The first step in applying the powder coat is to clean the part. It must be completely clear of grease, oil or dirt. This includes oil from the skin that may be transferred from handling the piece. Usually when cleaning the item is sandblasted or an acid bath used to clear debris, then brushed to remove remaining grit and moisture.
Applying the Powder Coat
After being cleaned off, the item is connected to an electrode which gives it a positive electrical charge. The powder is then applied using a Corona Gun, which is similar to a paint sprayer, but contains the powder coat, a thermoset (or heat curing) polymer which has a negative electrical charge. As the powder is blown over the part, the positive and negative charges are magnetically attracted to one another, causing the powder to cling to the part, like a balloon sticks to a wall from static electricity.
After the item is completely covered in powder, it is placed into an industrial oven. Once inside, the oven bakes the powder onto the piece. The powder does not simply melt over the part; rather, some of the powder carbonizes from the heat, a process which releases no noticeable gas or smoke. The remaining powder bonds to the carbonized powder at a molecular level.
This leaves behind a rock-hard shell which is highly resistant to scratches, chipping or rubbing off. After the part cools, it is ready to go, with a coat of vibrant color that forms perfectly to every contour of the item in question.
Do you have a metal part that needs coloring, and you don’t think that paint is the right solution? The powder coating process might be perfect for you. If you have any questions about the process of powder coating to color metal parts, we can help. Feel free to read over the services we offer and then give us a call today for more information.