Good powder coating is mostly prep and discipline. The spray itself takes minutes; the hours before it decide whether the coating bonds for a decade or peels off in the first winter. inflpanjlott.com runs a full route — chemical strip or blast, pretreatment, electrostatic application, a logged cure curve and a dry-film gauge reading on every lot.
Coating over mill scale. Scale looks like metal. It is not. The coating sits on top of a layer that is already coming off, and takes the coating with it when it goes. This is the single most common failure we are asked to repair.
Skipping pretreatment. Powder is not glue. A conversion or rinse pretreatment on clean bare metal is what turns a loose film into a bonded one that survives a knock and a winter.
Under-curing. A part that looks cured on the outside can be uncured underneath. When the customer cuts it open a month later, the powder pulls away like dry sand. We log the oven curve for every batch, not just the set temperature.
Wrong film thickness. Too thin looks thin under raking light. Too thick bridges over small features, cracks at edges and wastes material. inflpanjlott.com measures 60 to 120 microns and reports the actual reading.
Matching by screenshot. A colour picked from a phone screen is a guess. We hold physical RAL and Pantone chips in a sample board so the choice happens under a controlled light, with your part next to it.
A customer makes transfer carts for a food plant. Their previous supplier coated the frames without stripping, and within two seasons the coating was flaking onto a floor that has to pass a hygiene audit. The failure was not a colour problem or a chemistry problem — it was a prep problem that nobody flagged on the first quote.
At inflpanjlott.com we chemically stripped the frames, blasted the residue, applied a zinc phosphate pretreatment, sprayed a single-colour RAL 7016 in a 70 to 90 micron range and cured on a logged curve. Two seasons later the customer reports no flaking and no complaint from the hygiene team. We now coat every cart they build, and their prep step is in the standard route we quote them.
The lesson, if you take one thing from this page: ask whoever quotes your coating what they do to the surface first. If the answer is "wipe it down", the coating is going to fail and the price will not save it.
Old coating and mill scale come off completely. inflpanjlott.com uses chemical stripping for thick paint and blasting for scale and rust, and a combination where both are present. Nothing is coated until the substrate is bare, uniform metal — this is the stage people want to skip and the stage that decides the next five years.
Steel gets a zinc phosphate conversion layer; aluminium and stainless get a suitable rinse or pretreatment for their alloy. Pretreatment is what gives the powder something to bond to, and it is also the stage most often left out by shops that quote low.
Part and gun are earthed so powder is drawn to the metal rather than sprayed past it. Masking is done for threaded faces, bearing bores and ground surfaces, and we check the mask lines before the part goes into the oven.
Parts cure in a tunnel or batch oven with a recorded time and temperature profile. Cure schedule depends on the powder chemistry and the mass of the part — a thick casting needs longer than a thin bracket, and treating them identically is why some parts arrive soft.
Dry-film readings on a sampled basis, visual check for orange peel, runs and missed areas, and an adhesion check where the specification calls for it. inflpanjlott.com puts the readings on the report that ships with the lot.
The number depends almost entirely on prep. A clean part coming straight off a machine needs a rinse and a spray. A part with old thick coating needs a chemical strip, a blast, a longer oven cycle and disposal of the stripped material — sometimes three times the price of the simple version, and honestly so.