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Liquid Finishes

Decoration and protection of metals are quasi always associated.For the purpose, all kinds of surface treatments exist (chrome or nickel plating, aluminum coating, etc.), and other coatings. In this particular area, paints fill in a large opening. Paints are universally utilized, and can be applied to just about everything: wood, metal, stone, leather, plastics, elastomeres… Paints by themselves are not a finished product, and the quality of the application will be depending on all the steps of its implementation, generally known as “the painting system”.The steps are :

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surface preparation (pre-treatment)

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spraying of the materials ( varnishes, tints, paints…)

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curingwhatever kind of parts are being sprayed.For your information, we will review here the basics of each of those steps.

Surface preparation (pre-treatment)

This is the whole host of treatments, mechanical or chemical that any surface must be subjected to, prior to the application of the first layer of paint, tint or varnish. An appropriate surface treatment is the essential premise for a good protection and the final visual aspect of the finished part. Surface treatment is often the most extensive, and the most expensive area of a painting system.

Material Pre-treatment Chemical Steel :sand and shot blastingacid brushing Aluminum : brushing vapor blastWood :sanding Plastics : flaming torch plasma

Once treated, the surfaces must be:

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Free of powdered or non adherent residues,

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Free of oil, grease, humidityTo get a very good anti-corrosion protection, mostly on metals, one industrial sprays:

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either a primer, or a filler

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or an anti-corrosion paintA primer is a liquid material at approximately 16 s, CA4 ( or Ford #4 cup),which is sprayed as a thin film, designed to penetrated the unevenness of the metal’s surface. The phosphoric acid in the primer, attacks the metal surface, resulting in an isolating and inert phosphate. Primers are appreciated for their very good adhesion to metals. They MUST be coated with paint, which will eventually shield them.An anti-corrosion paint is applied in thicker industrial films than primers. As theycontain corrosion inhibitors, they protect metals chemically and mechanically. They save time, as one applies in one pass the corrosion inhibitor and the mechanical protection. These materials are often used for infrastructures and metallic carpentry, as they offer the choice of being left as is, or of being covered with a film of colored finish.

Selection guide - Liquid solutions 2004