Powder coating can be used to coat many types of materials. The most common material is metal, but you can also powder coat wood, plastic, composites, glass, and MDF. The first consideration for coating objects besides metal, is can it withstand the temperature. Most plastics will melt when subjected to 400 degree heat for any length of time so it is important to research exactly what your object is made of before you try to powder coat it.
|This glass vase was powder coated red for Valentines Day.|
How can you powder coat non-metallic items when they aren't electrically conductive?
When powder coating metal, the powder is electro-statically attracted to the metal as long as it is grounded. Well your average plastic, wood, or glass object is not electrically conductive. If you try to spray powder on them, the powder will just fall off and end up on the ground. The solution to powder coating these items is pre-heating. You can heat up the object in the oven, remove the object and powder coat it before it cools. When the powder hits the heated part, it will slightly melt on contact, causing it to stick. After coating the entire part like this, you then place the part back in the oven and cure it like normal.
Something you must watch out for when powder coating a pre-heated item is that it is very easy to put on too thick of a coating. Because the powder is melting as soon as it hits the part, it makes it difficult to judge how much powder is on the part. If a coating is too thick, it can run like paint, it can show craters, and the chip resistance will suffer. A similar method is called hot-flocking. This method involves heating the part up to the cure temperature of the powder(usually 400 degrees F), removing the item from the oven and immediately spraying with powder. The powder will melt and flow out instantly, using this technique greatly increases the chances of too thick of a coating however.
The ability to coat several types of materials is something that is not very well-known but it allows you to apply the same beautiful finishes that can with metal, to many other objects. Next time you are feeling creative, grab a glass from your cabinet, mask off some neat designs, and see what you can come up with.
Powder coated wood by The Powder Coating Institute.