Short answer: National Polyester Putty is a two-pack, polyester-based repair and dent filler for automotive bodywork and levelling wood, on wood and steel. Mix base and hardener 98:2 by weight and use it within 3 to 5 minutes at 30°C. It builds 100 to 1000 microns per coat and can be wet sanded after 20 to 30 minutes or dry sanded after 50 to 60 minutes.
Polyester Putty or N.C. Putty?
| Polyester Putty | N.C. Putty | |
|---|---|---|
| Pack | Two (98:2 by weight) | Single, ready to use |
| Build per coat | 100 to 1000 µm | 40 to 50 µm |
| Working time | 3 to 5 min pot life | No pot life |
| Sanding | Wet 20 to 30 min, dry 50 to 60 min | Hard dry 4 to 5 h |
| Best for | Dents and deep repairs | Fine glazing |
Key facts
| Type | Two-pack polyester putty |
| Uses | Automotive repair and dent filling; levelling wood; on wood and steel |
| Finish and colour | Matt, grey |
| Volume solids | 99 ± 1% |
| Mixing ratio | Base 98 : hardener 2, by weight |
| Pot life at 30°C | 3 to 5 minutes |
| Film per coat | 100 to 1000 microns |
| Sanding at 30°C | Wet sand after 20 to 30 minutes; dry sand after 50 to 60 minutes |
| Application | Glazing knife; no thinning |
| Cleaning | National Lacquer Thinner |
| Flash point (mixed) | 7°C |
| Shelf life | 6 months, sealed |
Step 1: prepare
- Steel: degrease, then remove rust to Sa 2.5 or St 2, per National’s surface preparation guide.
- Wood: dry, rubbed down with glass paper and dusted.
- Apply one coat of N.C. Primer Surfacer first, as the system lists.
Step 2: the system
- N.C. Primer Surfacer, one coat.
- Polyester Putty, one coat, sanded.
- N.C. Primer Surfacer, one coat.
- N.C. Auto Lacquer Topcoat or Clear, two coats.
Mixing maths
| Base | Hardener (98:2 by weight) |
|---|---|
| 100 g | about 2 g |
| 250 g | about 5 g |
| 500 g | about 10 g |
At 99% solids, almost all the putty stays on the surface. A litre spread at 1000 microns covers about 1 m²; at 100 microns about 10 m². Real repairs are patchy, so buy by the size of the damage, not the panel.
Mistakes to avoid
- Mixing a large batch. At 3 to 5 minutes’ pot life, small batches waste less.
- Guessing the hardener. Weigh it at 2% of the base.
- Thinning it. The sheet says no thinning.
- Keeping stock too long. Shelf life is 6 months, shorter than most National products.
Frequently asked questions
Can I use it on walls?
It is listed for wood and steel. For wall cracks, use Joint Filler.
Is it flammable?
Yes. The mixed product’s flash point is 7°C. Ventilate well and read the safety data sheet.
Buy in Sharjah and Dubai
Al Tashteb Al Saree is an authorised National Paints retailer in Bu-Tina, Sharjah. Message us on WhatsApp for Polyester Putty.
Sources
All via AEC Online, retrieved 4 November 2026. Calculations are our own. The main image is illustrative.
