45 Second Tests for Powder Coating Quality

Posted on Posted on 9th Feb 2017

If you thought doing a quality test on a powder coated steel product like a fence would be difficult think again and read on.

Have you ever painted a house? How much time did you invest in cleaning and preparing the surface before getting stuck into the painting? We all know that how long the paint sticks and looks good, depends in large part on the quality of the surface preparation.

Painting is about looks and protection

Tubular steel fencing is powder coated (painted) for two main reasons: to look good and to make the fence last longer by protecting the steel from corrosion. When the quality of the powder coating process is of a low standard then the coating can fail to deliver these two essential functions. The quicker the deterioration of the coating and the corrosion of the fence, the shorter its service life and the higher its true price.

A good finish delivers strong visual appeal and value

To briefly elaborate: the powder coating provides a colour, gloss and a smooth texture to the finish. Together these elements determine the visual appeal of the fencing itself and the aesthetic value that the fence adds to the space in which it is installed. Obviously when the coating peels (delaminates) away from the steel (the substrate) it detracts from the visual appeal of the fence. The fence looking ‘second hand’ can result in the area or amenity that is fenced being less attractive for people to use (for example, a playground) and/ or reduce the financial value of the property (for example, the front fence of a commercial property).

A good finish resists corrosion for years to come

The coating provides barrier corrosion protection by way of preventing moisture and corrosive elements (salt water, pollutants) coming into contact with the steel resulting the in the corrosion (rusting) of the fence and thus reduce the service life of the fence. Corrosion of the fence reduces the strength of the fence, which can in turn make the fence non-compliant (for example, with child safety requirements). Corrosion will also detract from the visual appeal of the fence.

Testing the finish to the Australian Standard

Looks can be deceiving. To simply look at powder coated fencing material when it is new, it is hard to assess the quality of the powder coating. However, this video clip shows two simple tests you can carry out on the product to determine if the powder coating complies with the Australian Standard AS4506:2005 Metal finishing - Thermoset powder coatings.

As you can see in the above video clip, the powder coating on the non-conforming sample looks fine but the two tests show that it has serious quality issues. We would expect the powder coating on the non-conforming sample to fail (delaminate) within about two years in outdoor conditions. The result being that a modest initial price saving is quickly eliminated.

Cross hatch test: Pass result