Resin for Primers
Primer is a pre-coat for paint that ensures better longevity and quality finish to the substrate on which it’s supposed to be applied on. Hence the main objective of primer is to adhere to the surface and form a binding layer between the surface and the applied paint. Once the formulation of primer is done, properties like durability along with better filling and binding properties, better and smoother finish of the surface are kept in mind. Primer makers, achieve such chemical union, by using special formulas, as in the case of aluminum primer, but more often, this is achieved through controlling the primer’s physical properties such as porosity, flexibility, tackiness and likewise.
In practice, Primer is generally used while painting and sealing of porous materials, such as concrete or wood. Priming is necessary if the substrate is not water resistant and if it will be exposed to the elements of nature. There are many special primers also which are applied on various metal surfaces specifically for its protection and corrosion resistance properties.
Primers for wood
There are numerous reasons for applying Primer before painting a wood surface. Foremost reason being, wood is very porous substrate and can absorb the solvent part from paint when applied directly, resulting in drying of the paint in a premature stage. The resin used in manufacturing of the paints undergo complex chemical reactions during the process of drying , which demands that the water or solvent used in the system evaporates gradually, rather than being absorbed quickly by the underlying substrate, which leaves the paint coat uncured. Hence a few layers of priming on the surface beforehand help the paint to undergo proper completion and achieve the desired look.
When wood is exposed to moisture, the thin film of paint covering on the surface will still be water permeable. The end result will be warped parts, mildew, and dry rot. Addition of the Primer layers hence adds on to the waterproofing potentials of the paint.
Primers for metal
Metals specifically untreated Aluminum, Iron requires a primer coating. Special formulation primers designed particularly for metal is still highly recommended if some proportions of the metal substance are susceptible to be exposed to moisture. If in any case water seeps through to the bare metal, oxidation shall soon begin. Metal primers might contain additional materials like sacrificial zinc, to protect the core against oxidation and corrosion.
Impurities like metal hydroxides or oxides on the substrate surface provide a very loose surface for the paint to adhere to. Paint coat comes off in large flakes when applied to such surfaces directly. Using a primer will provide extra resistance coat for such scenario. One more reason for using primer on metal surface could be to avoid roughening of the surface. The best solution is though to clean the metal thoroughly before applying any coat to it, but when this is not a viable option, special kinds of primers can be used that can chemically convert rust to the solid metal salts. Though such surfaces lack the strength and luster in comparison to the cleaner metal, it is still better than weak, porous rust.
We manufacture ready to use mediums that are capable to make Aluminium based corrosion resistant paints. CASKYD is used by both large and small scale primer manufacturing companies for betterment in the overall properties like resistance against water, acid, alkali and other chemicals, fighting against corrosion, enhancing brilliance, increasing flexibility and as well as imparting sturdiness. INDUSTRIAL RESINS & CHEMICALS™ supplies CNSL and Cardanol Resin which can be specifically utilised for the formulation of a huge variant of primers.