Coverage figures quoted per litre are best-case. The number to plan with is millilitres per square metre – and it has a two-fold spread you need to account for before you order.
The only figure that matters
The datasheet consumption for N-Bond is 2.5 to 5 ml per square metre. Every “m² per litre” claim you will see is derived from that, including ours.
At the thin end, one litre covers 400 m². At the thick end, 200 m². We plan at 320 m² per litre – about 3.1 ml/m² – because that is where normal float glass work in a normal workshop actually lands.
If you are quoting a job, use 320 m²/litre. If you are ordering stock for a substrate you have never primed before, budget at 200 m²/litre and you will not run out mid-run.
Why the spread is so wide
The manufacturer names three variables, and all three are under your control:
- Substrate. Glass and ceramic sit at the efficient end. On metal, consumption depends on the surface finish.
- Surface structure. Anything textured or etched has more area to wet than its nominal dimensions suggest.
- Application temperature. This is the one that quietly doubles your usage. On a hot panel the solvent flashes off before the primer levels, so you apply more, get clouding, and then polish some of it back off. Work between +5 and +35 °C.
What each pack actually covers
| Pack | Plan for | Realistic range | Typical use |
|---|---|---|---|
| Wet wipe sachet | up to 2 m² | fixed | Qualifying a new ink or substrate |
| 250 ml | 80 m² | 50-100 m² | Occasional glass work, small batches |
| 1 litre | 320 m² | 200-400 m² | Regular production |
| 20 litre drum | 6,400 m² | 4,000-8,000 m² | Roller coater or spray line |
The sachet figure is stated by the manufacturer. The rest are calculated from the 2.5-5 ml/m² consumption spec.
Start with a sachet, not a bottle
A single sachet covers up to 2 m² – enough for a test panel and a cross-cut check, which is exactly what you should do before committing any production run on an ink or substrate you have not used with this primer before.
That is not a sales line. The manufacturer’s own instruction is to verify adhesion on untested media first, and on acrylic, metals and composites to run trials as a matter of course. A sachet costs you one panel and twenty minutes. A failed run costs you the glass. If you are not sure what a failure looks like, the four mistakes that cause UV ink to peel off glass covers the checks worth running.
Over-applying costs you twice
The instinct with a primer is that a heavier coat is a safer coat. With N-Bond it is the opposite, and it is expensive in both directions.
Too much primer gives worse adhesion, not better. N-Bond is a monolayer technology – it is not film building. Applied as a wet film it clouds, and the excess has to be polished off before printing. Meanwhile you have burned through stock at up to twice the necessary rate.
Visible haze after drying is your signal that you are over the mark. Reduce the amount on the next panel. Applied correctly the layer is invisible, streak free, and leaves the light transmission of the glass unchanged.
Buying the bigger pack only pays if you store it properly
Sealed in its original container, N-Bond keeps for 36 months from delivery. That makes the litre sensible for most workshops – but the shelf life assumes the container is treated correctly:
- Reseal tightly after every use. The solvent is a fast, residue-free evaporating alcohol blend and it does not wait for you.
- Do not dilute it and do not mix it with anything else.
- Store above 4 °C.
- Sachets go somewhere cool and dry, out of direct sunlight and away from heat.
Safety. N-Bond is a flammable liquid and vapour with a flash point of 21 °C. Store and apply away from sources of ignition, in a well-ventilated area, and read the Safety Data Sheet before use.
Quick reference
| Consumption | 2.5-5 ml/m² |
| Planning coverage, glass and ceramic | 320 m²/litre |
| Coverage on metal | depends on surface finish |
| Sachet coverage | up to 2 m² |
| Application temperature | +5 to +35 °C |
| Storage temperature | not below 4 °C |
| Shelf life, sealed | 36 months |
| Pack sizes | sachet, 250 ml, 1 litre, 20 litre drum |
Coverage rates are a guideline and vary with substrate, surface structure and application temperature.