Short answer: National Synthetic Enamel Gloss I is a general-purpose, alkyd-based enamel that dries to a high-gloss film. National describes it as resistant to cracking, abrasion and washing, with good weather resistance, for interior and exterior walls, steel and wood. It goes over Synthetic Undercoat and a primer suited to the surface. It is touch dry in 6 hours and needs 18 hours before a second coat at 30°C. Thin with National G.P. Thinner.
Gloss I or another National enamel?
| Enamel | Finish | Best known for | Touch dry | Recoat (30°C) |
|---|---|---|---|---|
| Gloss I | High gloss | General purpose, walls and steel | 6 h | 18 h |
| Gloss II | High gloss | Fast drying; equipment and vehicle repaint | 1 h | 8 h |
| Flat/Matt | Matt | Interior walls, ceilings, wood, metal | 2 to 3 h | 8 h |
| Eco Enamel | Gloss, semi-gloss or flat | Described as lead-free | 3 to 4 h | 8 h |
Gloss I’s main limit is time: 18 hours between coats at 30°C. On jobs where a second coat must go on the same day, Gloss II is the National alternative.
Key facts
| Decorative sheet | Protective sheet | |
|---|---|---|
| Type | Alkyd synthetic enamel, single pack | |
| Finish and colours | High gloss; National shade card | |
| Volume solids | 45 ± 2% | 50 ± 2% |
| Specific gravity | 1.05 ± 0.05 (white and pastels) | |
| Spreading rate | 11 to 15 m² per litre | 12.5 to 16.5 m² per litre |
| Film per coat | 30 to 40 µm dry (65 to 90 wet) | 30 to 40 µm dry (60 to 80 wet) |
| Drying at 30°C | Touch dry 6 h; recoat 18 h; hard dry 24 h | |
| Application | Brush, roller or spray (airless 2200 psi, tip 0.015 to 0.020 inch; air 50 psi) | |
| Thinning | 5 to 15% | Airless 5 to 10%, air 10 to 15%, brush 10% |
| Thinner, flash point | National G.P. Thinner; 38°C | |
| Shelf life | 18 months, sealed | |
Step 1: prepare the surface
| Surface | National’s preparation |
|---|---|
| Steel | Degrease; clean to St 2 or blast to Sa 2.5; prime clean and dry. |
| Concrete and plaster | Clean, dry and sound; remove laitance, efflorescence, dust and grease. Fresh concrete can reach pH 13, so use an alkali-resistant primer. |
| Wood | Dry and clean; smooth with glass paper; apply knotting or preservative if needed; then prime. |
Step 2: build the system
| Surface | Primer and filler | Undercoat | Gloss I |
|---|---|---|---|
| Concrete, walls | PVA Primer Sealer × 1, Stucco Filler × 2 | Synthetic Undercoat × 1 | × 1 |
| Steel | Red Oxide Primer × 1 | × 1 | × 2 |
| Wood (doors, frames) | Wood Primer × 1, Stucco Filler × 2 | × 1 | × 1 |
| Galvanised | Wash Primer, Zinc Chromate × 1 | × 1 | × 1 (40 µm) |
For structural steel, National’s specifier sets out heavier alkyd builds referenced to BS 5493: two Red Oxide coats, two undercoats and one Gloss coat (165 to 190 microns) for non-polluted air, or two Gloss coats (190 to 230 microns) for polluted air.
What the numbers mean
- Coverage = volume solids × 10 ÷ dry film. At 45%: 450 ÷ 30 = 15, 450 ÷ 40 ≈ 11.3 m² per litre (the decorative range).
- Wet film for a 35-micron coat = 35 ÷ 0.45 ≈ 78 microns. Stay within the sheet’s 30 to 40 micron range per coat and build with a second coat rather than one heavy one.
How much to buy
| Area | 1 coat | 2 coats |
|---|---|---|
| 20 m² (about four doors, both sides) | 1.3 to 1.8 L | 2.7 to 3.6 L |
| 50 m² | 3.3 to 4.5 L | 6.7 to 9.1 L |
| 100 m² | 6.7 to 9.1 L | 13.3 to 18.2 L |
Mistakes to avoid
- Recoating the same day. 18 hours at 30°C is the sheet’s minimum, and longer in cool or humid weather.
- Going straight onto primer. National’s systems put Synthetic Undercoat underneath for holdout and opacity.
- Using water or acrylic thinner. It is an alkyd; use G.P. Thinner.
- Painting walls without filler. Gloss shows every flaw; National’s wall system uses two coats of Stucco Filler.
Frequently asked questions
Can I use it outside?
Yes. Both data sheets list interior and exterior use and describe good weather resistance.
Gloss enamel or Gloss Emulsion on walls?
Gloss I is a solvent-based alkyd that recoats in 18 hours; Gloss Emulsion is water-based acrylic and recoats in 6 to 8 hours. For masonry, wood and plastic with less odour, consider the emulsion.
Buy in Sharjah and Dubai
Al Tashteb Al Saree is an authorised National Paints retailer in Bu-Tina, Sharjah. Message us on WhatsApp with your shade for Gloss I, undercoat, primer and G.P. Thinner.
Sources
- National Synthetic Enamel Gloss I, decorative data sheet (PDF)
- National Synthetic Enamel Gloss I, protective data sheet (PDF)
- National Paints surface preparation guide, Sec. A-2 (PDF)
- National Paints systems specifier (PDF)
All via AEC Online, retrieved 4 November 2026. Quantities are our own calculations. The main image is illustrative.
