When a surface is painted, primers do several jobs. Besides improving adhesion, they can build a corrosion-resistant layer, neutralize rust and hide minor surface defects. By the order of application, primers are either primary or secondary. Every job needs the right primer or the right combination of primers, and to choose it you have to know what each of them is for and how it behaves.
Primers are divided into primary and secondary. A primary primer goes directly onto the surface as the first coat. A secondary primer is applied over a primary one: it builds a resilient underlayer and fills minor defects, so that the surface is as smooth and uniform as possible before the paint is applied. Some products combine several properties and work both as a primer and as a topcoat.
Rust stop protective spray 3 in 1
Primary primer
For use on metal surfaces, including surfaces attacked by corrosion. A 3-in-1 product: rust neutralizer, primer and paint. Just clean the surface with a wire brush to remove loose rust and dirt, degrease it, and the direct-to-rust paint is ready to be applied. The corrosion inhibitors in the formula stop the rust from spreading and protect the metal. The color range is matched to the RAL standard.
Alkyd spray primer
Primary primer
Suitable for ferrous metal surfaces that are free of corrosion. Any spots of corrosion must be sanded off and treated with a rust converter before application. Its main advantage is better adhesion of the following paint coats to the metal. Its drawback is a fairly long drying time; it is not meant to be sanded. It can also be applied over old paintwork and on wood. It is best used together with alkyd paints.
Acrylic spray primer
Primary/Secondary primer
The most versatile primer: it can be used both as a primary and as a secondary primer. It has excellent adhesion to wood, plastic and metal. It dries fast, can be applied in a thick coat, sands easily, hides defects in the substrate and gives a perfectly smooth surface. It can also work as an isolator primer. Suitable for acrylic and alkyd paints.
Transparent plastic primer.
Adhesive activator
Primary primer for plastic
For preparing plastic surfaces for painting. It considerably improves the adhesion of paints to plastics. Apply it in one thin coat. It contains a small amount of aluminum powder that acts as an application indicator: it is enough for the powder to spread over the surface as an even light haze. Flexible, fast drying. Any primer or paint can be applied over it.
Spray paint for plastic acrylic RAL
Primary/Secondary primer
It can be used both as a primary primer on plastic and as a secondary primer in combination with the KU-6000 adhesion activator. A 2-in-1 product: it combines high adhesion to plastics with high strength and wear resistance, so it can also be used as a topcoat. The color range is matched to the RAL standard.
Furniture nitrocellulose matt varnish
Primary primer
A varnish is normally a topcoat, but it also works well as a primer. It lays down evenly on a wooden surface and gives excellent adhesion for the following paint coats. A matt nitrocellulose varnish keeps the texture of the wood visible.