Solution of Bubbles or Pin-holes in epoxy coatings？

1. Workpiece degreasing and rust removal is not complete or phosphating after washing is not clean
The strict control of surface treatment quality

2. Moisture not thoroughly dried after surface treatment
Appropriately increase the pre-drying temperature

3. The surface of the workpiece has pores (such as cast iron parts, aluminum castings, galvanized steel, etc. with many capillaries on the surface)
A) It is recommended to use preheating and baking for 20 minutes at 20°C above the powder curing temperature to avoid the presence of tiny air bubbles.
B) Add defoaming additives in powder coating to help eliminate bubbles.

4. Static Breakdown
A) adjust the static voltage down
B) pull the distance between the gun and the workpiece, and pay attention to the gun should not work on the workpiece local place for a long time to stay
 
5. Powder coating is too thick
Control the proper coating thickness

6. Compressed air contains moisture
Improve compressed air purification equipment

7. The quality of the powder itself
Contact with powder suppliers