Powder coating troubleshooting

Start with the symptom, not random changes to equipment settings. These practical checks help coating specialists organise an investigation.

These are diagnostic pointers, not a product-specific process specification. Before maintenance, safely stop and isolate equipment according to its manual. Change one parameter at a time, within permitted limits, and record the outcome.

Uneven powder delivery

Check powder flow, moisture, feed hoses, filters and compressed-air condition. Compare with a previously satisfactory batch. Increasing air pressure without diagnosis is not a universal remedy.

Poor coverage in recesses

Review hanger cleanliness and workpiece grounding, part geometry, gun position and the equipment maker’s charging guidance. Test on a part with the same geometry.

Poor adhesion or flaking

Check oil and rust removal, pretreatment, substrate dryness and the actual workpiece temperature profile. Oven-air temperature alone does not prove adequate cure.

Craters, inclusions or contamination

Look for oil, silicone, dust or residues of an incompatible coating. Check compressed air, cleaning materials and colour-change procedures. Run a separate clean-panel trial.

Pinholes and small voids

Review substrate porosity, residual moisture and measured film thickness. Galvanised or cast parts may need a separately agreed process. Do not raise oven temperature without checking the product limits.

Orange peel and uneven flow

Compare film thickness with the technical data sheet and check the heating profile and powder storage condition. Assess against the agreed sample for that product: a textured finish is not a smooth finish.

Colour, gloss or metallic effect varies

Compare batch numbers, thickness, curing conditions and reclaim proportion. Assess metallic finishes under consistent lighting and part orientation. Agree a control sample before the production run.

What to send with a problem report

Send product and batch codes, substrate and pretreatment details, film-thickness readings, the temperature profile and clear photos. State whether all parts are affected and what changed in the process.

Sources and further reading

Information reviewed on 20 October 2026.

Let’s discuss your question

Send the product code, intended application and your question. Include the document or physical-sample details if available.

Send an enquiry