The two leading types of paint finishes for exterior metal products that we use on our products are Wet coat/baked enamel and Powder Coat . Depending on what product you choose for your project will typically be the deciding factor for which type of paint finish that it will have and Contrary to what you may hear these products are different and as time will tell most likely perform differently.
Powder Coating involves three basic steps. These processes can be done in very expensive and elaborate facilities or believe it or not in somebody’s garage With any painting process the prep is very important and done with chemicals.
- Part preparation / pre-treatment Chemical pre-treatments involve the use of phosphates or chromates in submersion or spray application. These often occur in multiple stages and consist of degreasing, etching, de-smutting, various rinses and the final phosphating or chromating of the substrate. The pre-treatment process both cleans and improves bonding of the powder to the metal.. It is also the biggest difference between the many powder coaters we have worked with over the years. Most facilities are not equipped with the proper cleaning facilities to give you a ready piece of material for coating.
- The powder application, The most common way of applying the powder coating to metal objects is to spray the powder using an electrostatic gun. The object is then heated, and the powder melts into a uniform film, and is then cooled to form a hard coating.
- Curing. This cure process, requires a certain temperature for a certain length of time in order to reach full cure and establish the full film properties for which the material was designed. Normally the powders cure at 200°C (390°F) for 10 minutes.
- Powder coatings emit zero or near zero volatile organic compounds.
- Powder coating overspray can be recycled and thus it is possible to achieve nearly 100% use of the coating.
- Small jobs are much more cost effective than using a Baked Enamel/Wet coat
- Very hard and expensive to get Written warranty from powder coaters due to powder coatings will break down when exposed to UV rays between 5 to 10 years
- Touch up colors very hard to match powder colors
- Scratches are very noticeable due to powder is much thicker than Baked Enamel/Wet coat
Liquid Coat/baked enamel is the type of paint that most people think of when paint is mentioned. It comes in liquid form and is sprayed to a substrate. The types of paint can vary allowing you to pick how the paint will hold up to certain elements, discolor/oxidize and how long it will last. The process of applying the paint can be done vertically or horizontally .Since our products consist of Aluminum extrusions I am going describe the vertical Paint line system which is how 99 percent of our material is coated. This vertical line is a state of the art multimillion dollar paint line and every step is in a controlled environment. The paint of choice is a Duracron coating manufactured by PPG who isthe leading paint manufacturer in the world. The first stage is a five stage pre treatment process. It is then cured prior to printing. The paint process is done on a vertical pint line which carries the extrusions from the beginning to the end of the process and electro statically applied so the finish is very thin and consistent. The materials are then run thru the oven process. This cures the paint giving a fish that cannot be obtained by just spraying paint to a substrate.
- Custom Colors are easily mixed and able to reproduce.
- Finish is thinner than powder coating so touching up is easier and less noticed
- Written Warranties from the paint manufacturers are easily obtained
- Small jobs are not economical
- Lead times tend to be longer
In closing, Working with these paints for thirty plus years(longer than Most paint warranties) has allowed me to see the Advantages of each type of paint and how each of them perform over time. We utilize both types of paint in our business but the majority of our products are liquid coated /Baked enamel. This is mainly due to the fact we believe the quality of the paint and process is superior for our type of product . Most important when comes to getting a written warranty for our customers it has never been an issue or a fictitious piece of paper.