Powder coating is a phenomenal product which, in terms of advantages, far surpasses liquid paint products in a myriad of ways. Powder-coating farm equipment, vehicles, patio furniture, metal fencing, military components and medical instruments only scratches the surface regarding the types of products that can be optimally protected and beautified, via powder-coating products.
Though some do-it-yourself projects involving powder coating can turn out quite nicely and look quite professional, unless one is extremely well-versed in powder coating-procedures, it is best to utilize the expertise of those who know, exactly, what they are doing. Unprofessional attempts at powder coating can leave a finished product with less-than-stellar results. For example, very characteristic defects – such a rumpled finish – is the result of electrostatics when excessive charge builds up in a powder coating layer. This can happen if the powder is applied too thickly or two quickly. Also, if one is not entirely well-versed on powder-coating procedures, flaking, bubbling, chipping and cracking can severely compromise the finish. Procedural errors such as inaccurate temperatures, incorrect pre-treatment, inadequate curing, and more, can wreak havoc on the appearance of the final surface. Powder coating involves layering; and any botched stage of the coating process can adversely affect the next layer.
Let’s take a look at a few examples where DIY powder coating projects can result in powder-coating failures:
*** Insufficient Substrate Preparation
If the surface to be powder-coated is not properly smoothed out – such as blasted metal or sharp edges – premature corrosion can set in even if a thicker layer of powder-coating is applied. However, even when thicker applications are utilized, microscopic protrusions may not be fully covered, especially in recessed areas that can be difficult to reach. If any area is not properly coated due to inadequate substrate preparation, it will compromise the longevity and durability of the finished surface.
Also, the substrate or the composition of the substrate can negatively affect the adhesion and/or corrosion-resistant properties of the powder-coating. Underestimating the effect of the composition of the substrate can result in minimized performance of the powder-coat.
*** Inadequate Pre-Treatment
It is easy for sediment to accumulate around the bottom of objects that have been hung for the pre-treatment rinse. If sediment remains unnoticed and is allowed to dry, failure of the powder-coating should be expected. Also, when incorrect pre-treatment chemicals are used or if edges, corners, and/or recessed areas are overlooked during any pre-treatment procedure (sometimes these areas are a challenge regarding penetration of pre-treatment), corrosion will result. Corrosion typically starts on the edges or in deep recesses where the coverage of the powder-coat is thinner and where the pre-treatment has a more-difficult time penetrating.
*** Coating Too Thick or Too Thin
How powder-coating is applied is vitally important. When applied too thinly, not only will an uneven appearance become a problem, but corrosion is sure to set in since water, debris and salt particles can become embedded into even the smallest crevices and migrate under the thin coating. If powder-coat is applied too thickly, any inherent flexibility and impact resistance of the powder-coating will be dramatically reduced. When powder-coating is applied as multiple layers, each layer must be absolutely perfect to guarantee the coating’s optimal performance for pliability and protection.
*** Improper Curing
Proper curing during the powder-coating process is crucial; and even if the object’s surface has been properly pre-treated, inadequate curing will cause minimized durability, color degradation, and a dulled finish. The time required to completely cure at a given temperature should never be rushed. Under-cured powder coating can appear smooth and glossy, but a break-down in performance will, soon, be noticed.
*** Failure to take Environment into Account
In real-estate, it’s all about ‘location, location, location’; and the same can be said for powder-coating. Underestimating how environmental factors can affect powder-coating is a common error. Coastal locations, for example, should be especially noted since extremely high UV indexes and continuous salty, wet environments will take their toll on incompatible powder-coating products. Planning for the most-adverse atmospheric conditions is extremely important.
If the powder-coating product used in a marine or coastal environment is unsuitable, water, dirt and salt will permeate the film and lead to early corrosion. It’s important to realize that not all powder-coatings are created equally, nor are all powder-coatings designed to work optimally in every type of environment.