Why is Primer Important? Professional Application Guide

Primer is the most critical yet most overlooked step in paint application. Paint applications performed without primer, despite appearing visually satisfactory, lead to problems in the long term.

4 Core Functions of Primer

Adhesion: Creates a strong bond between paint and surface. Especially on new plaster, gypsum, and concrete surfaces, primer improves paint adhesion by 40–60%.

Absorption Control: Absorbent surfaces such as new plaster and concrete rapidly absorb paint. This causes uneven appearance and increased paint consumption. Primer balances the surface's absorption.

Alkali Blocking: New cement and concrete surfaces are alkaline. This alkalinity causes standard paint to fade and deteriorate over time. Alkali-blocking primer eliminates this risk.

Stain and Rust Barrier: When paint is applied directly to rusted or stained surfaces, stains bleed through the paint film. Blocking primer prevents this stain transfer.

Which Primer for Which Surface?

New plaster/gypsum → Concentrated Clear Primer (diluted with 20–30% water) Old/absorbent concrete → Blocking Acrylic Primer Stained/faded surfaces → Blocking Acrylic Primer (undiluted) Raw concrete appearance → Luna Tones Raw Concrete Primer

Application Details

Primer is applied with roller or brush. After drying (4–8 hours), proceed to the paint coat. With clear primer, the surface color remains unchanged, retaining concrete and plaster tone. Blocking primer has a light gray tone and covers underlying stains or old paint.