May 17, 2023

One Year of SilcoPrime

This month marks the one-year anniversary of the release of Pecora SilcoPrime. Pecora’s SilcoPrime is an STPU (silyl-terminated polyurethane) based interlaminary primer that is specifically formulated to promote the adhesion of exterior-grade, non-silicone-based architectural wall coatings when applied over existing silicone-based wall coatings. In celebration we would like to explore what a primer is, types of architectural coating primers, and a little bit about SilcoPrime.


A primer is typically a pigmented or non-pigmented fluid applied material, designed to enhance the adhesion of various top layers of sealants, adhesives, and coatings to porous and nonporous substrates while providing a consistent foundation for application of subsequent coatings or sealants.  A primer’s main functionality is to modify a surface in order to provide a chemical or mechanical bridge, typically bonding a fluid material to a solid surface. Choosing the right primer for specific applications or surfaces is of paramount importance as it will ensure the durability of applied architectural coatings or sealants.

Types of Architectural Coating Primers:

The three most typical types of architectural coatings primers are listed below: (each comes with advantages and disadvantages):

  1. Oil-based/ Alkyd Primer (the most commonly used primer):

Used in exterior/interior application on various finished and unfinished surfaces, including wood, steel, metals etc. where fluctuations due to temperature is expected. However, high VOC and long drying time may make it an undesirable type of primer to some.

  1. Latex/ water-based Acrylic Primer: Flexible and fast drying primer associated with low VOC levels and a simple water cleanup.
  2. Shellac Primer: Used for interior coating applications, typically not as versatile as the other two previously mentioned types.


Typical Exterior Architectural Finish Coat Primer

An exterior wall primer is an adhesion promoting prime coat for use when applying exterior grade water or solvent cut architectural finish coatings. Some of the typical benefits of primer use include enhancement of the wall coatings’ appearance, ensuring higher performing finishes, providing top layer durability, blocking out odors, increased hiding of top coat, and reducing cost/labor by eliminating the numbers of top coat applications. 


SilcoPrime is a specially formulated translucent white prime coat utilizing a proprietary STPU based polymer system. When applied over clean and dry existing silicone-based wall coatings, it promotes the adhesion of most exterior-grade, acrylic based, architectural wall coatings (i.e. Pecora WeatherClad). This adhesion promoting, VOC compliant, low-odor, fast curing primer is specifically formulated to act as an interlaminar primer for restoration and enhancement of exterior walls with a preexisting silicone-based coating.

The SilcoPrime primer option is unique in that, traditionally, only a silicone-based coating would be considered compatible when refreshing or re-coating an existing silicone based architectural wall coating. With the introduction of Pecora SilcoPrime, an option now exists to apply acrylic architectural topcoats directly over existing silicone based architectural coatings. Advantages include cost savings, elimination of atmospheric contamination and discoloration typical of silicone-based coatings, and the flexibility to choose from a wide array of colors and coating manufacturers when considering a recoat application.

As with any re-coat project of significant scope, surface preparation, field testing, and close communications with the manufacturers technical group is a key to success. Pecora SilcoPrime represents a significant tool in surface preparation procedures when seeking a restoration option on buildings that have previously been coated with a silicone based architectural coating.

To check out one of our SilcoPrime projects, click here.

For more information on SilcoPrime from the specification data sheet, please visit our website To speak with someone from our expert team of highly qualified Technical Services Group, please email or by phone at (800) 523-6688. Our Technical Services staff offers training in product technology and use and provides the technical assistance you require in the planning and implementation of your project.


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