Whether you need a primer depends on how your hull is currently built up. What matters most is this: F2 should always be applied on a stable, clean, and dry surface. 

Short answer

  • New or freshly sanded hull: Yes – first apply a suitable barrier coat/primer, then the F2 system.
  • Intact barrier coat already in place: No additional primer – sand, clean, then build up F2.
  • Old antifouling: Antifouling is not a primer. We recommend sanding off the layers until you reach a sound, stable barrier coat/primer.
  • Solvent-based primer: Let it fully cure, sand, degrease – then start directly with F2 EcoHull Adhesive Coat (without F2 EcoPrimer).

1. When you need an additional primer

New or bare hull

For new hulls or hulls that have been completely sanded back, we recommend applying a solvent-free barrier coat (e.g. Hempel High Protect II) underneath F2 to protect the hull against moisture. After that, the F2 system is built on top of this barrier coat – in this case, no F2 EcoPrimer is required. 

Important: We recommend using a solvent-free primer (e.g. Hempel High Protect II) so you can then continue with the F2 system as specified in the application instructions. 

If you use solvent-based primers, the surface must be allowed to off-gas for at least 7 days at 20 °C before it is sanded again (P180) and degreased. Only then can you proceed with the F2 EcoHull Adhesive Coat. 

2. When you don’t need an additional primer

Intact barrier coat in place

If there is already a sound barrier coat in place (no blisters, cracks, flaking), you normally don’t need to apply another primer. 

  • Remove old antifouling down to the sound, load-bearing barrier coat (if present).
  • Sand the barrier coat (e.g. P180) and clean thoroughly.
  • Degrease with F2 Degreasing Solution (1:10 with fresh water, wipe in one direction only, rinse, let dry).
  • Then build up the F2 system according to the instructions (F2 EcoPrimer if specified, F2 EcoHull Adhesive Coat, F2 EcoHull Top Coat).

3. Antifouling is not a primer

Conventional antifoulings (especially soft systems) are not designed to serve as a base layer for a modern fouling-release system like F2. If these layers remain underneath F2, they can later swell, chalk, or detach – and this can compromise the entire F2 coating. 

Our recommendation is therefore clear: sand off old antifouling layers consistently until you reach a sound, load-bearing barrier coat/primer.