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How is Stainless Steel Powder-Coated?

June 29, 2022

Powder coating is an effective way of protecting metal from corrosion. It involves coating the piece with a thin layer of protective polymer, resulting in a strong product with extra resistance. While stainless steel is already corrosion-resistant, it can benefit from powder-coating. Here, we outline the essential steps in the process.

Table of Contents

How is Stainless Steel Powder-Coated?
Surface cleaning
Passivating
Blasting
Primer and powder coating
Decoration
High-temperature curing
Curing
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Powder Coasting of Stainless Steel Parts in a Metal Fabrication in Mount Isa

Surface cleaning

Before you begin power-coating stainless steel, you must ensure you have a clean workpiece. Surface cleaning removes contaminants or impurities like oil and dirt which can prevent the polymer from binding to the metal.

Passivating

In the passivating process, metals are treated with corrosive chemicals to remove a thin layer of surface material. It's essential this step is done very carefully, as the chemicals used have the ability to cause corrosion. Through passivating, areas in which there is a disturbance of surface distribution of alloying elements - particularly near welds or around scratches or dents - are removed.

Blasting

Even with the care and caution taken in surface cleaning and passivating, impurities can still occur. These final residual imperfections are removed with sandblasting. Following this step, the piece is cleaned carefully and thoroughly to remove residue from blasting.

Primer and powder coating

Layers of primer and powder coating are applied to the piece using an electrostatic charge. The use of a charge rather than paint prevents pinholes on the finished surface. While these layers are very thin, they're exceptionally strong.

Decoration

In some instances, decorative treatments might be applied after the primer and powder coating. Patterns or impressions can be created on the metal using a stencil or template.

High-temperature curing

After the powder coat is applied, it needs to be cured or "baked" onto the surface of the steel. The curing process happens at high temperatures (usually at around 185 degrees) and hardens the powder coat so that it is durable and long-lasting. It's important during this step to maintain a consistent temperature for a period of time, often around 15 minutes, before being removed from the oven and cooled.

Curing

The powder coat must be cured or "baked" onto the steel. The metal is cured at a consistently high temperature, usually around 185 degrees, for a period of around fifteen minutes to ensure the effective hardening of the resin. Curing ensures the steel will be durable, long-lasting and able to withstand corrosion, abrasion and scratches.

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When you need quality steel fabrication, welding, rubber lining or labour-hire in Mount Isa, look no further than HardRok Engineering. We're a local, family-owned business committed to high-quality workmanship, a flexible approach, and our fast turnaround in dealing with breakdowns or repairs. We proudly offer custom designs, manufacturing and installation, all under one roof, so you can be confident whatever your need, we'll meet it to the highest standards. Contact us today on 07 4749 1770 to speak to our friendly team, to learn more about what we do or to arrange a quote.