Primer is the coat people most often skip, and the one that decides whether the paint above it lasts. Short answer: National Acrylic Primer (W.B.) is a white, water-based, alkali-resistant primer for interior and exterior concrete and plaster, and the primer National names for its Shield texture coatings. Use one coat on new or porous masonry before emulsion or texture. This guide follows National Paints’ technical data sheet.
Key facts
| Type | Water-based acrylic primer with antifungal and antibacterial additives |
| Properties | Adhesion, alkali resistance, penetration and sealing |
| Colour / finish | White, smooth matt |
| Volume solids | 36 ± 2% |
| Spreading rate | 10 to 12 m² per litre (theoretical) |
| Film per coat | 30 to 35 microns dry |
| Drying at 30°C | Touch dry 1 hour; recoat 2 to 3 hours |
| Thinning | 10 to 15% water |
| Application | Brush, roller or spray |
| Shelf life | 18 months, sealed |
When you need it
- New plaster or concrete, inside or out: the alkali resistance protects the paint from the fresh cement surface.
- Before textured finishes: National lists it as the primer for Shield texture coatings, and as an option before Nutex under Acrylic Rock. See National Tex textured coatings.
- Interior smooth finishes: it is one of four primers in National’s interior system, before Stucco Filler and emulsion. See the interior wall system.
When you may not
On a sound, previously painted wall in the same type of paint, a repaint usually goes straight on after cleaning and spot repairs. Prime bare patches where filler or new plaster shows. For metal, use a metal primer instead; see painting steel with National Paints.
How much to buy
| Area, one coat | At 10 to 12 m²/L | Packs |
|---|---|---|
| 35 m² | About 3 to 3.5 L | One 3.6 L gallon |
| 100 m² | About 8 to 10 L | Three 3.6 L gallons |
| 200 m² | About 17 to 20 L | One 18 L drum plus a gallon |
Frequently asked questions
Can it be used outside?
Yes. National lists it for exterior and interior concrete and plaster.
How many coats?
National’s recommended system is one coat of primer, then one or two coats of the topcoat system.
Which National masonry primer?
| Acrylic Primer (W.B.) | PVA Primer White | PVA Primer Sealer | |
|---|---|---|---|
| Colour | White | White | Clear |
| Volume solids | 36% | 35% | 30% |
| m² per litre | 10 to 12 | 10 to 11.5 | 10 to 15 |
| Recoat (30°C) | 2 to 3 h | 2 to 3 h | 2 to 3 h |
| Application | Brush, roller or spray | Brush, roller or spray | Brush or roller |
| Listed under | Shield textures, Synplast, interior emulsions | Acrylic Rock, Nutex | Eggshell Silky, Tex, Graffio |
Step 1: prepare the wall
- National’s surface preparation guide asks for a clean, dry, sound surface. Exteriors are washed with high-pressure water (2200 psi minimum) and left to dry.
- Remove laitance and efflorescence. New concrete can reach pH 13, which is why an alkali-resistant primer goes first.
- Acid-etch or roughen very smooth concrete. Fill cracks with Joint Filler and open block with Block Filler.
What the numbers mean
Coverage = volume solids × 10 ÷ dry film: 36 × 10 ÷ 30 = 12 and 36 × 10 ÷ 35 ≈ 10.3 m² per litre, matching the sheet’s 10 to 12. The 10 to 15% water added for application does not add film, so work out litres from the unthinned figure.
Mistakes to avoid
- Priming damp or dusty walls. Wash, dry and brush down first.
- Swapping primers under Shield textures. Their sheets name Acrylic Primer (W.B.).
- Topcoating too soon. Wait 2 to 3 hours at 30°C.
Which topcoats go on it?
National names it under Shield Fine Silk, Shield Tex Silk, Synplast, Super Matt and Acrylic Super, among others.
Buy National Acrylic Primer in Sharjah and Dubai
Al Tashteb Al Saree is an authorised National Paints retailer. Shop the 3.6 L gallon or 18 L drum, or message us on WhatsApp.
Sources
- National Acrylic Primer (W.B.) data sheet (PDF, via AEC Online)
- National Paints: Paint Systems Specifier (PDF)
- National Paints surface preparation guide, Sec. A-2 (PDF)
Retrieved 3 November 2026. Quantities are our own calculations. The main image is illustrative.
