Why is proper preparation important?
80% of the final result of powder coating depends on the preparation. Even if we use top-quality powder paint and modern equipment, if the workpiece is poorly prepared, the coating will not adhere durably.
Here are the 7 most common mistakes our customers make, in our experience — and how you can avoid them.
1. Plastic or rubber parts on the workpiece
The problem: Curing in the powder coating oven takes place at 180–200°C. At this temperature, plastic melts, rubber burns, and adhesive runs.
The solution: Remove all plastic, rubber and adhesive residues from the workpiece before bringing it for coating. This also applies to stickers, seals, plastic plugs and wheelless valves.
2. Oily, greasy surface before sandblasting
The problem: If the workpiece is oily or greasy and goes for sandblasting, the oil contaminates the blasting media (steel shot, corundum). This contaminated media then contaminates every subsequent workpiece as well.
The solution: If you also need sandblasting, the part must be free of oil and grease. If necessary, we can carry out prior degreasing — but please mention this in advance with your quote request.
3. Un-deburred laser-cut edges
The problem: After laser cutting, burrs remain on the edges and corners — sharp, pointed pieces of metal. In these spots the powder coating does not cover evenly, and the layer is thinner, so it wears off sooner.
The solution: Bring laser-cut parts deburred for coating. Edges should be rounded and burrs removed.
4. Missing hanging hole
The problem: During powder coating, the workpiece is suspended from the conveyor system. This requires a hanging hole. If there isn’t one, we can add it, but this is not part of the basic service and takes extra time.
The solution: Plan for the hanging hole during manufacturing. Usually an 8–10 mm hole in a less visible spot on the part is sufficient.
5. Old paint or rust on the surface
The problem: If there is old paint or rust on the surface, the powder coating does not adhere directly to the metal but to the old layer — which can come off over time, taking the new layer with it.
The solution: We remove old paint and rust by sandblasting. This is an extra cost, but the durable result is worth it. With us, sandblasting and powder coating take place in one location, in a single facility.
6. Poorly specified colour or finish type
The problem: “Some sort of grey” or “like my neighbour’s fence” — these do not produce an accurate specification. A later colour change means a full re-coat.
The solution: Use a RAL code to specify the colour. If you don’t know the exact code, check our RAL Colour Chart page, or bring a sample piece with you. It is also worth deciding the finish type (matt, gloss, structured) in advance.
7. Drop-off without an appointment
The problem: If you bring workpieces without notice, the oven may be full or the requested colour may not be in stock, and you will have made an unnecessary trip.
The solution: Always arrange the drop-off by phone. Call +36 20 455-25-44, and we will agree on quantity, deadline and preparation requirements.
Summary
| Mistake | Solution |
|---|---|
| Plastic/rubber on the part | Remove it |
| Oily surface | Degrease, or mention in advance |
| Un-deburred edges | Deburr them |
| No hanging hole | Plan it in manufacturing |
| Old paint/rust | Sandblasting |
| Inaccurate colour spec | Use a RAL code |
| Drop-off without notice | Call first |
Have a question about preparation? Call us: +36 20 455-25-44 or request a quote online.