Powder Coating Process
The basic process of powder coating is generally, pretty straightforward. All
types of metal can be powder coated such as alloys, aluminum, steel, iron,
etc. If you have a new metal project you can sometimes by-pass the 1st step.
Your powder coater will be able to make this determination.
1. BLAST IT
Sandblasting is the best way to prep a metal surface in need of restoration.
The point of blasting is to remove any mil-scale, rust, or existing coating and
to etch the surface prior to coating. This etching, or “blast profile” is one step
to ensure proper adhesion by creating a mechanical bond when the powder is
fully cured to the surface. It also removes dirt, grime, and corrosion. Existing
paint or powder coated finishes may require a chemical stripping first before
the blasting process can begin. This can save time and keeps blasting to a
minimum.
2. PREP IT
Prepping consists of applying a metal prep chemical solution to neutralize
surface impurities, cleaning off any lingering debris and prevent rust and
corrosion.
Depending on the type of metal there are several kinds of solutions your
powder coater can use to enhance the surface before coating. If this is a
concern for you make sure to ask your powder coater about what they will
be using; this is a step that should not be missed.
The last step of preparation before powder is to be applied is called
outgassing. Outgassing is basically heating up the part to slightly higher
temperature that the powder cures at, in order to release any gasses
trapped in the substrate and to burn off any other oil or solvent
contaminates that may still be left on the surface.
3. POWDER IT
When fully prepped and dry your metal project will be ready for powder
coating.
The coating itself is done through a dry powder, electrostatic
application process, whereby, the metal object is grounded and the
atomized powder travels through a highly positively charged air stream, in
order for the powder to be attracted to the substrate, and bond well
during the curing stage.
There are many colors and brands of powder to choose from depending
on the needs of the customer and the end use of the project. There are
outdoor rated and interior only rated colors and powders. Some
powders require clear coats or base primers which could add to an
increase in costs.
4. CURE IT
The cure times for metal can range depending on how long it takes the
oven to get to temp and the size of the oven.
Typically, temperature ranging from 350 degrees Fahrenheit to 450
degrees Fahrenheit are required for the powder to heat up enough to
make the mechanical and chemical bonds that make powder coating
finishes so much more durable than paint finishing. Once the right temp
is achieved it takes 15-30 minutes for your metal part to achieve the fully
cured state. Once the full cure of the finish has been completed the part is
completely finished and can be used or installed as soon as it has cooled
down to safe handling temperature.
