Short answer: if the part is metal, can go into an oven and fits the line, powder coating almost always gives a more durable and cheaper result. Wet paint comes in when the part contains a heat-sensitive material, is very large, or a special effect is required.
Decision table
| Criterion | Powder coating | Wet paint |
|---|---|---|
| Typical film thickness | 60–120 microns in a single coat | 25–50 microns, usually multi-coat |
| Impact and scratch resistance | High; the film is thick and cross-linked | Medium; thickness is limited |
| Solvent / VOC | None | Present; released during drying |
| Overspray | Recovered by cyclone | Not recoverable; it is waste |
| Drying | Ready for use at oven exit | Needs inter-coat and final drying time |
| Heat-sensitive material | Not suitable; the oven runs at 180–200 °C | Suitable |
| Very large parts | Limited by oven and booth size | Almost unlimited flexibility |
| Colour blends and special effects | Limited; each colour is a separate powder | Wide; blending and gradients possible |
| Small touch-ups | Difficult; the part must be re-cured | Easy; can be done in place |
| Unit cost in series work | Low | High |
The limits of powder coating
Powder is not the right method for every job, and saying so at the start is cheaper than saying it after taking the work. Wet paint is the better answer in three situations:
- Heat-sensitive components. If the part carries a gasket, plastic, electronics or a heat-treated zone, the oven regime will damage them.
- Size beyond the oven. Parts exceeding the conveyor and oven envelope need either split fabrication or wet paint.
- Blends and special effects. In powder each colour is a separate product; gradients or on-site mixing are not possible.
How the decision is made
Four questions settle most jobs: is the part metal? Does it tolerate 180–200 °C? Does its largest dimension fit the line? Is the colour single and flat? Four yeses mean the decision is made; a single no is the point worth discussing.
Send the dimensions, the material and the service environment, and we will determine together which method is right and whether it fits our line.