Most coating complaints we are asked to solve are not coating problems. They start before the first drop of paint reaches the panel: dust left after sanding, burrs on the edges, pores that were never filled, or a board that came out of storage too wet.
Sanding sets the surface, not the finish
Calibration sanding brings the panel to thickness and gives the primer something to key into. What it also does is generate dust and raise fine fibres on the surface. A panel that leaves the sander looks clean and is not. Coating straight off the sander traps that dust under the film, where it shows up as specks and a rough hand feel after curing — and by then the only fix is sanding the coat back off.
Dust removal is the cheapest quality stage on the line
A dust remover runs the panel between rotating brush rollers and an extraction hood, lifting chips and fibres off the surface and pulling them away. It is a small machine with a small power draw, and it removes a defect class that is expensive to correct downstream.
- Single-sided is enough when only one face is coated — cabinet panels, single-sided UV lines. See the precision single-sided dust remover.
- Double-sided cleans both faces in one pass and is the standard unit on a basic coating line. See the precision double-sided dust remover (FZCH-1300D, 1300 mm working width, 10–50 mm panel thickness).
Place it after sanding and immediately before the first coating station. Distance matters: every metre of open conveyor between the dust remover and the coater is a chance for airborne dust to settle back on the panel.
Filling pores: UV putty before primer
MDF edges, particleboard and open-grain veneers absorb coating unevenly. Without a fill stage, primer sinks into the pores and the top coat telegraphs every one of them — a matt, pitted look on what should be a level surface.
The fill coat is normally applied with a double roller coater: the first roller lays putty into the pores, the second scrapes the surplus back off, so you fill without building unnecessary film thickness. Cure, sand lightly, then dust-remove again before primer. This sand-and-clean cycle between coats is the part most buyers underestimate when they plan a line’s length.
Moisture and temperature
Wood-based panels move with their moisture content. A board coated at high moisture will release it later, lifting or cracking the film. Condition panels in the same environment as the coating hall before they enter the line, and keep the hall temperature stable — coating viscosity, and therefore film thickness, changes with it.
The sequence that avoids rework
- 1. Calibration sanding to thickness.
- 2. Dust removal, both faces if both are coated.
- 3. UV putty fill, cure, light sand, dust removal again.
- 4. Primer, IR levelling, cure, sand, dust removal.
- 5. Top coat and final cure.
Every dust-removal step in that list is there because the step before it made dust. Skip one and it becomes visible in the finish.
Send us your panel material, thickness and coating system and we will lay out the pretreatment section that fits it.