Frequently Asked Questions
What are Powder Coatings?
Powder Coatings are a solvent-free paint system in powder form. Powder Coatings consist of resin/binder, pigments, fillers and flow agents blended together and ground into powder form. The powder is applied most commonly by electrostatic spray where the powder particles are charged and the grounded substrate attracts the charged particles which forms a layer of powder. When heated for a specified time and temperature this layer of powder melts, flows and chemically cross-links to produce a solid, continuous coating.
Powder Coatings are a durable, decorative finish which has outstanding mechanical properties such as UV stability, flexibility, adhesion and chemical and corrosion resistance. Powder Coatings are an environmentally friendly alternative to solvent based paints with little or no release of VOC emissions.
What are the main causes for a powder coated finish to peel/flake off the surface?
The main reason for powder to peel or flake off the substrate is due to lack of adhesion between the powder and the substrate. This can be caused in a number of ways such as poor surface preparation, where the surface may be contaminated with oils, paints, chemical sealers, etc.
Under curing is also another issue with peeling powder coat. Powder which is under cured lacks many of the mechanical properties of a cured powder. Aesthetically, the powder finish may look great however it will have poor adhesion and be quite brittle which makes it susceptible to chipping, cracking and flaking off from the substrate.
What is the “bake cycle” of the powder?
This depends on the powder and the resin system used. Most of our polyester powders require a bake schedule of 200°C for 10 minutes at metal temperature. Other polyesters, polyester-epoxy hybrids and pure epoxies require 180°C for 10 minutes at metal temperature. The “...at metal temperature” is very important. The powders require the metal to be at the specified temperature for the 10 minutes to achieve a full cure. Depending on the oven and metal substrate, the time taken to get the metal to temperature varies. This needs to be taken into account when determining the bake schedule for each job.
Can I order small quantities of Powder?
Yes, we can provide our customers small quantities of powder as requested. It’s all part of the service.
Does the powder coated finish need time to harden/dry like wet paint?
No. Once the powder coated finish is removed from the oven after baking all it needs is time to cool down. “If it’s cool to touch, it’s cool to take.”