There is a shortcut you hear often in this trade: powder coated means the budget version. That equation is wrong. Powder coating is used not because it is cheap but because it carries no laminate layer. There is no film to peel, no panel to delaminate, no edge banding to draw moisture. That is exactly why it is the standard surface on fire doors and pressed sheet panel doors.

The process

The coating arrives as dry powder, not liquid. The spray gun charges the powder at high voltage; the charged particles cling to the earthed steel and wrap around edges and corners. The leaf then goes into an oven at around 180-200 °C, where the powder melts, flows, fuses and cools into one hard film. Overspray is collected in the booth and reused, so material waste is far lower than with liquid paint.

Pretreatment is half the job

Service life is decided before any powder is sprayed. The sequence is degreasing to remove mill oil and machining residue, rinsing so no chemical stays on the surface, phosphating or a nano-ceramic pretreatment to create the micro-profile the coating grips and to delay corrosion creep, then drying so no water remains to blister in the oven. Skip these and the finish looks perfect for a year, then lifts outward from the first scratch. When you assess a supplier, ask about the pretreatment line rather than the oven temperature.

What it gives you

  • No laminate layer, so no edge lifting.
  • Higher film build than liquid paint, so better scratch and impact resistance.
  • Even thickness on corners and folds, where liquid paint thins out.
  • Solvent-free, with minimal emissions during cure.
  • Polyester-based powders hold colour outdoors against UV.

Texture and colour

Powder is not limited to flat gloss. Matt, satin, fine texture, sand and hammer-texture finishes are all available, and textured surfaces hide scratches and fingerprints in high-traffic entrances. Colour is specified to RAL. One caution for export buyers: the same RAL number can shift slightly between powder batches, which is visible on creams and whites and invisible on black steel doors and dark anthracite. If your order ships in stages, ask for the whole quantity to be coated in one run.

Where it is specified

Fire doors carry no combustible cladding because it would compromise the tested assembly, so the surface is powder coat directly on steel. Pressed-pattern leaves also use it, since film cladding softens the corners of deep embossing while powder keeps the pattern sharp; our sheet panel door production is built entirely on this finish. Gate leaves, shaft hatches and meter cabinet doors are coated the same way.

Repair and maintenance

Repair is the weak point. Full repair needs an oven, so deep scratches are touched in with matched paint, leaving a small difference in sheen. Textured finishes hide touch-ups better. Ask for a touch-up pen in your RAL code with the delivery rather than hunting for one later. Wipe the surface twice a year with a damp cloth, more often in coastal locations where salt accumulates, and avoid abrasive pads and solvents. Treat any rust spot immediately, while it is still a spot. Send us your openings in centimetres and the RAL code you want and we will quote accordingly; orders load in Istanbul for road or container freight.